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Zoology Unit 2
Terms in this set (76)
Compare and contrast synapomorphies of the phylums Nematomorpha and Nematoda. Draw the life cycle of a nematomorph.
Nematoda: most are less than 5 cm long, they have amphids, and adults have a gut.
Nematomorpha: can be up to 1 meter in length, no gut in adults, no amphids
Same: have cuticle, lack segmentation, and have longitudinal muscles
1. The free living larval stage is aquatic
2. The larva burrow into the gut of an aquatic insect and encyst
3. The cyst survives the metamorphosis of this paratenic host
3. An insect, usually a cricket, consumes the paratenic host containing the cyst
4. Worms live in the hemocoel of the cricket
5. Adult worms manipulate the behavior of the cricket, and it commits 'suicide' by jumping into water. Once the worms sense the presence of water they start actively exiting the host.
What is a cuticle? Define ecdysis
The cuticle is a protective, noncellular, organic layer secreted by the external epithelium of many invertebrates. Ecdysis is the shedding of the cuticle layer, otherwise known as molting.
What is a hydrostatic skeleton?
The hydrostatic skeleton is a mass of fluid of plastic parenchyma enclosed within a muscular wall to provide support necessary for antagonistic muscular action.
Distinguish between a solenocyte from a flame-cell protonephridium.
A solenocyte is a special type of flame bulb that bears a flagella instead of a tuft of flagella; the flagellum wafts excretory products along the tubule.
Found in : Annelida, Platyhelminthes, Rotifera, and other invertebrates
A flame cell protonephridium is one or several small cells that contains a tuft of flagella; it is a specialized excretory cell found in "lower" freshwater invertebrates, like a kidney removing waste materials.
Found in: some Nematoda, Platyhelminthes, Flatworms, and Rotifera
Explain two peculiar features of the body-wall muscles in nematodes.
One is the external tube. It is the body wall consisting externally of a cuticle layer and internally of longitudinal muscle, it is unable to elongate the body. Another is the fact that the muscle arm extends to the nerve cord rather than the nerve extending to the muscle.
Where do kinorhynchs live?
They have been collected as far north as Greenland and as far south as Antarctica. Most live in marine sand or mud from the intertidal zone to a depth of 5000 to 8,000 meters, but some are found in algal mats or holdfasts, sandy beaches. Others have been found living on hydrozoans, bryozoans, or sponges.
In what habitats would you encounter tardigrades? How does cryptobiosis in tardigrades increase the likelihood of survival?
Tardigrades can be found in almost every habitat; mountaintops, deep sea, tropical rain forest, and antarctic. Most species live in freshwater terrestrial environments in water film surrounding moss, lichen, damp soil; some marine. Cryptobiosis, or suspended animation, during which metabolism is virtually imperceptible, allows tardigrades to withstand prolonged harsh environmental conditions for long periods of time, up to many years; tardigrades may then virtually come back to life in the presence of moisture and proper temperatures;
Describe and outline the life cycle of hookworms.
Eggs are contained in feces, where the hookworm embryo develops. Juveniles hatch and develop in the soil. Humans can be be infected via oral route or penetration of the skin. Once in the human, the hookworm travels to the lungs where they enter the aveoli. This causes the human to cough and swallow, allowing the worm to enter the capillary beds of the small intestine where they finish development and mate.
Describe and outline the life cycle of dog heartworms.
Mosquito ingest microfilariae from an infected dog. The microfilariae develop into larva in the mosquito. The larva enter the dog via mosquito saliva, when the mosquito are feeding on the dog. Larva migrate to the heart. Adult worms reproduce, 6 months later microfilariae are released into the blood.
Describe and outline the life cycle of Wuchereria.
Mosquito ingest microfilariae from an infected human. Microfilariae pass through the gut into hemocoel and develop into juveniles. The juveniles enter the human via mosquito saliva, when the mosquito are feeding on the human. Larva travel though lymphatic system until they find a lymph node. Adult worms mature in lymphatic vessels. Adult worms give birth to microfilariae.
Describe and outline the life cycle of Loa loa.
Horse or deer fly ingest microfilariae while feeding on human. Juveniles develop in the fly and are injected into the human when they are bitten by the fly. Juveniles migrate to the eye of the human where they mature. Microfilariae are produced and enter the bloodstream.
Describe and outline the life cycle of Guinea worm.
A water flea ingests the Guinea Worm larva. A human drinks water containing the infected water fleas. The fleas are digested, releasing the larva into abdominal tissue where mating occurs. Female worms move though body. 1 year later a worm emerges burning blister forms, and when the person goes to water to cool the limb in the water. Upon entering the water, the worm releases larva into the water.
Describe and outline the life cycle of Trichuris trichura.
Eggs are passed in feces. Once entering the soil, they become infective. After ingestion, this usually happens by soil-contaminated hands or food, the eggs hatch in the small intestine and release larva that mature and become adults in the colon. The adults are fixed at this location. Females begin to oviposit lay eggs in the cecum. The life span of adults in approximately one year.
Describe and outline the life cycle of Trichinella spiralis.
Raw or poorly cooked meat containing encysted juveniles is swallowed, and worms move to the intestine where they mature. Adult worms burrow in the mucosa of the small intestine where females produce living young. These penetrate blood vessels and are carried throughout the body; eventually they penetrate skeletal muscle cells and turn muscle cells into nurse cells that nourish the worm.
Describe and outline the life cycle of pin worm.
Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area. Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. Following ingestion of infective eggs, the larvae hatch in the small intestine and the adults establish themselves in the colon. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area. The larvae contained inside the eggs develop in 4 to 6 hours under optimal conditions.
Describe and outline the life cycle of ascaris worms.
Adult worms live in the lumen of the small intestine. A female produce eggs daily, which are passed with the feces. Fertile eggs embryonate and become infective. After infective eggs are swallowed, the larvae hatch, invade the intestinal mucosa, and are carried via the portal vein/system, then systemic circulation to the lungs. The larvae mature further in the lungs, penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed. Upon reaching the small intestine, they develop into adult worms.
"If all the matter in the universe except the ____ were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of _____. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain _____. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile _____ parasites." The missing term in this passage is: _________
The nematode Coenorhabditis elegans has allowed scientists to develop "fate maps" tracing cell lines back to cell origins. The trait of nematodes and some other related groups where they have a set number of cell divisions leading to the same number of body cells in an adult is called ___________.
Minute, mostly terrestrial animals living in the water film that surrounds mosses and lichens belong to the phylum _______________.
A state in which metabolism is extremely low or has stopped, and in which the water content of the body is reduced to a few percent, is called _______________.
A marine sample yields small worms and you are asked to identify them. It has 13 segments, a complete gut, introvert with hooked spines, no external cilia, well developed cuticle, and protonephridia. It belongs to the phylum ______________.
2) Define the following words: Elephantiasis, nematode, Trichinella, hookworm, diploid, heartworm, haploid, pinworm, and nematomorphs.
Elephantiasis: Chronic, often extreme enlargement and hardening of cutaneous and subcutaneous tissue, especially of the legs and external genitals, resulting from lymphatic obstruction and usually caused by infestation of the lymph glands and vessels with a filarial worm.
Nematode: any of several worms of the Phylum Menatoda, having unsegmented, cylindrical bodies, often narrowing at each end, and including parasitic forms such as the hookworm and pinworm.
Trichinella: a nematode genus in the aphasmid group that causes trichinosis in humans and other carnivores
Hookworm: any of numerous small parasitic nematode worms of the family Ancylostomatidae, having a hooked mouthpart with which it fastens itself to the intestinal walls of its host, causing ancylostomiasis.
diploid: 2n chromosome number of cells
haploid: 1n chromosome number cells.
Heartworm: A filarial worm transmitted by mosquitoes and parasitic in the heart and associated blood vessels of dogs and other canids
Pinworm: Any of various small nematode worms of the family Oxyuridae that are parasitic on horses, rabbits, and other mammals. A species that infests human intestines and rectum.
Nematomorphs: Nematomorpha is a phylum of parasitic animals that are superficially morphologically similar to nematode worms. Can be seen in damp areas such as watering troughs, streams, puddles, and cisterns; parasitize arthropods.
Discuss the two phylogenetic theories of the phylum tardigrada. Describe the evidence for each idea. Where do you think the "water bears" fit into evolutionary relationships?
What is meant by the term Lophotrochozoa? What about Ecdysozoa? Propose and discuss the phylogeny of metazoans that includes this term. Include a complete cladogram to illustrate your proposed phylogeny. Make sure to include all relevant phyla. What evidence supports this view? If there is evidence that does not support this view make sure to include it in your discussion. Do you agree with this view?
Onychophorans share some features with arthropods and others with annelids. Discuss the characteristics of this phylum and which features are shared with arthropods and annelids. Discuss some possible phylogenetic implications of these patterns. Explain why this group confuses protostome phylogeny? Discuss the presence of velvet worms in the fossil record.
Discuss arthropod versus non-arthropod growth. Express animal growth in an arthropod versus a non-arthropod on a graph. Describe the layers of an arthropod cuticle and the process of molting.
Arthropods grow by molting, a process in which the exoskeleton (its rigidity does not allow room from growth) is periodically shed. The unprotected and vulnerable arthropod body then undergoes a period of rapid growth, forming a new cuticle or exoskeleton. This is a step by step process. Non-arthropods growth is linear/exponential; continual gradual growth until maximal genetic size is reached.
Procuticle is the inner layer and is covered with a thin, waxy, water-resistant out layer containing no chitin. Made up of an outer exocuticle (before molting) and the inner endocuticle (after molting).
Epicuticle is the outer layer and is much thinner than the procuticle. Moulting or ecdysis is the periodical shedding of the external part of the cuticle. Old procuticle separates from epidermis which secretes a new epicuticle, new exocuticle is secreted as molting fluid dissolve the old endocuticle, at ecdysis, the old cutcles are discarded, and in postechdysis, new cuticle is stretched and unfolded, and endocuticle is secreted.
What is a trilobite? When did trilobites dominate the seas? When did they go extinct? What are the three tagmata in a trilobite?
Trilobites dominated the sea in the Paleozoic era specifically during the Cambrian period and declined during the Ordovician period. They thrived about 500 million years ago and when extinct 200 (251.4) million years ago.
-cephalon with eyes, antennae
-thorax with multiple articulated segments
-pygidium or tail section of fused segments
Name each subphyla of arthopods, and give a few synapomorphies and example organisms for each. About how many species are described from each? Are arthropods monophyletic or polyphyletic? Explain the evidence in detail to support your conclusion. What are important distinguishing features of arthropods?
What are the tagmata and appendages on the head of crustaceans? What other important characteristics of Crustacea distinguish them from other arthropods?
The tagmata on crustaceans are the three regions of the body which are the cephalon (head), thorax, and abdomen. Crustaceans are segmented with one pair of appendages per segment and these segments are arranged into tagmata. They have biramous (two-parted) limbs and have a nauplius larvae form. Have two pairs of antennae and are marine.
Define each of the following: hemocoel, tergum, sternum, telson, protopod, exopod, endopod, epipod, endite, and exite.
tergum: dorsal part of an arthropod segment
sternum: ventral part of an arthropod segment
telson: posterior projection of the last body segment in many crustaceans
protopod: basal segments of crustacean biramous appendage, containing coxa and basis
exopod: lateral branch of biramous crustacean appendage
endopod: medial branch of a biramous appendage
epipod: a lateral process on the protopod of a crustacean appendage, often modified as a gill
endite: medial process on an arthropod limb
exite: process from lateral side of an arthropod limb
What is meant by homologous structures? What is meant by serial homology, and how do crustaceans show serial homology?
A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor; it's when very different animals have bones that appear very similar in form or function and seem to be related.
Serial homology is the adaptation of a series of similar organs to have different functions. Crustacean appendages have adapted to function in sensing their environment, defending against predators, swimming, walking, grasping, transferring sperm, generating water movement, and in gas exchange.
Briefly describe respiration and circulation in crayfishes. Briefly describe the function of antennal and maxillary glands in Crustacea. How does a crayfish detect changes in position?
The open circulatory system of the crayfish has no veins. Two arteries leave the heart, the abdominal aorta (toward the posterior) and the anterior dorsal aorta (toward the anterior). The open circulatory system is common to molluscs and arthropods. Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
Crayfish respire through the exoskeleton and through the gills which are around its legs. As the crayfish walks, the surface area of the gills spread so the water can pass through in order for the crayfish to breath.
The antennal and maxillary glands primarily regulate ionic balance. The total balance of salts and water is also controlled in part by the gut, which can absorb both. The antennal gland also has been shown to reabsorb glucose. Most crustaceans excrete the end product of nitrogen metabolism, in the form of ammonia, through the gills. Some of the more terrestrial forms produce urea or uric acid, which are far less toxic than ammonia. Urea and uric acid may be stored in special large cells near the bases of the legs or excreted without the loss of much water. Both have the same basic structure: an end sac and a convoluted duct that may expand into a bladder before opening to the outside. Antennal and maxillary glands are the excretory filaments in Crustacean. These primarily regulate ionic balance. These are tubular structure of the base of either the maxillae or antennea. These have end sacs called labyrinths which connect to the dorsal bladder via excretory tubes. Hydrostatic pressure forces excrement to move through the labyrinth down the excretory tubules to the bladder. The antennal and maxillary glands also reabsorb nutrients and organic materials.
Crayfish rely upon the tactile input from its second antennae to detect topographical changes in the environment and that such topographical changes can be retained for at least 24 hours.
Through saclike statocyst on the basal segment of each first antenna. These bear sensory setae that serve as statoliths along with grains of sand; animal changes position, so does grain of sand, which stimulate the brain; and the animal adjusts accordingly.
What is a nauplius? What is the difference between direct and indirect development in Crustacea?
A nauplius is the free swimming microscopic first larval stage of many crustaceans, having an unsegmented body; three pairs of appendages and a single median eye.
Direct and indirect development are terms that describe different processes of animal development. Animal development begins with a fertilized egg. The difference between direct and indirect development lies chiefly in the progression through the juvenile phase of life. The path from conception to a sexually mature adult creature is very different in these two processes. Direct development refers to the process of development in which an animal is born in a smaller version of its adult form. There is no major transition in the form of the animal from infancy to maturity. Animals who experience direct development (Reptiles, birds and mammals) may have a large amount of yolk in order to nourish the young, or the young may be fed directly by the mother's body. Both these methods of nourishing the young require a great deal of energy from the mother. Therefore, the number of offspring must necessarily be small. With indirect development (echinoderms, amphibians and insects undergo indirect development: butterflies, dragonflies, frogs), an animal's birth form is very different from the adult form. The embryo hatches from the egg in a larval form. The larva undergoes a drastic metamorphosis in order to achieve its adult stage. Animals that undergo indirect development lay numerous eggs. Because the eggs are small, they have relatively little yolk. Due to the small amount of yolk, the larva develops and hatches rapidly.
Describe the molting process in Crustacea, including the actions of hormones and the process of ecdysis.
The process of moulting in insects begins with the separation of the cuticle from the underlying epidermal cells (apolysis) and ends with the shedding of the old cuticle (ecdysis). In many of them it is initiated by an increase in the hormone ecdysone. After apolysis, moulting fluid is secreted into the space between the old cuticle and the epidermis, this contains inactive enzymes which are activated only after the new epicuticle is secreted. This prevents them from digesting the new procuticle as it is laid down. The lower regions of the old cuticle - the endocuticle and mesocuticle - are then digested by the enzymes and subsequently absorbed. The exocuticle and epicuticle resist digestion and are hence shed at ecdysis.
Compare and contrast Isopoda, Amphipoda, Euphausiacea, and Decopoda.
Isopoda: no carapace; antennules usually uniramous; sessile eyes; gills on abdominal appendages; body dorsoventrally flattened; woodlice
Amphipoda: no carapace; antennules often biramous; eyes usually sessile; gills on thoracic coxae; bilaterally compressed body form; sperm whale lice
Euphausiacea: carapace fused to all thoracic segments but not entirely enclosing gills, no maxilliped; all thoracic limbs with exopods; krill
Decapoda: all thoracic segments fused with and covered by a carapace; eyes on stalks; first 3 pairs of thoracic appendages modified to maxillipeds; shrimp, crab
What is the significance of Remipedia to the hypotheses concerning the origin of crustaceans?
Remipedia is a class of blind crustaceans found in coastal aquifers which contain saline groundwater, with populations identified in almost every ocean basin so far explored. At least seventeen living species have been identified. Remipedes are hermaphroditic crustaceans that occur exclusively in subterranean marine environments. The head region is armed with three pairs of powerful, raptorial limbs. However, it is their long, homonomously segmented trunk bearing biramous, paddle-shaped appendages that has led to the prevalent view that remipedes are primitive crustaceans, although this assumption has not yet been verified or falsified convincingly. Remipedia are crustaceans that resemble centipedes and were once thought to be an evolutionary link between Crustaceans and myriapoda due to superficial and morphological similarities like the gills, larva, naupiles, and decapods. Another evolutionary link could be biramous apendages from uniramous to two individual appendages to a biramous appendage. Today this is disproved through genetics that remipedia is not a link between myriapoda and crustacea.
What is a tongue worm, and where would it be found?
Any wormlike invertebrate of the subphylum Arthropoda, having two pairs of hooks at the sides of the mouth. A blood-sucking parasite that infests the nasal cavity of carnivores; different variations can be found globally. The larvae cause pain, itching, sneezing due to transnasal migration, dysphagia, vomiting and lymphadenopathy; a large bolus of worms may cause a fatal obstruction
Describe in detail the physiology and morphology of insect respiration.
Describe two basic types of insect life-cycles and give two examples of each.
What characteristics of hexapods distinguish them from all other arthropods?
Insects have segmented bodies, jointed legs, and external skeletons (exoskeletons). Insects are distinguished from other arthropods by their body, which is divided into three major regions: (1) the head, which bears the mouthparts, eyes, and a pair of antennae, (2) the three-segmented thorax, which usually has three pairs of legs (hence "Hexapoda") in adults and usually one or two pairs of wings, and (3) the many-segmented abdomen, which contains the digestive, excretory, and reproductive organs.
Compare and contrast the flight mechanism of a dragonfly compared to a house fly. Make sure to include the muscles and nerves in your discussion. Explain why indirect flight muscles can beat much more rapidly than direct flight muscles?
What major parts form an insect's gut, and how do these parts function?
Explain the difference between holometabolous and hemimetabolous metamorphosis in insects, including stages of each.
Describe hormonal control of metamorphosis in insects, including the action of each hormone and where each is produced.
What is diapause, and what is its adaptive value?
Diapause - a period of suspended development and growth accompanied by decreased metabolism in insects and some other animals. It is correlated with seasonal changes
Adaptive value (Darwinian fitness, fitness, selective value) - the balance of genetic advantages and disadvantages that determines the ability of an individual organism (or genotype) to survive and reproduce in a given environment. The environment, and the competition or struggle for survival within it, determine which individuals are fittest to achieve this, the 'fittest' being the individual (or genotype) that produces the largest number of offspring that later reach reproductive maturity.
Briefly describe three features that insects have evolved to avoid predation.
A foul smell or a bad taste is often enough to discourage a potential predator. Stink bugs, for example, have specialized exocrine glands located in the thorax or abdomen that produce foul-smelling hydrocarbons.
These chemicals accumulate in a small reservoir adjacent to the gland and are released onto the body surface only as needed. The larvae of certain swallowtail butterflies have eversible glands, called osmeteria, located just behind the head. When a caterpillar is disturbed, it rears up, everts the osmeteria to release a repellent volatile, and waves its body back and forth to ward off intruders.
Insects that blend in with their surroundings often manage to escape detection by predators and parasites. This tactic, called cryptic coloration, involves not only matching the colors of the background but also disrupting the outline of the body, eliminating reflective highlights from smooth body surfaces, and avoiding sudden movements that might betray location. Obviously, this tactic loses much of its effectiveness if an insect moves from one type of habitat to another. Well-camouflaged insects usually stay close to home or make only short trips and return quickly to the shelter of their protective cover. Many ground-dwelling grasshoppers and katydids, for example, have colors of mottled gray and brown that help them "disappear" against a background of dried leaves or gravel. On the other hand, closely related species that live in foliage are usually a shade of green that matches the surrounding leaves. The larvae of some lacewings improve their camouflage by attaching bits of moss or lichen from their environment onto the dorsal side of their body.
If a distinctive visual appearance is sufficient to protect an unpalatable insect from predation, then it stands to reason that other insects might also avoid predation by adopting a similar appearance. This ploy, essentially a form of "false advertising", was first recognized and described by Henry W. Bates in 1861. Today, it is commonly known as Batesian mimicry. Viceroy butterflies (mostly palatable to birds) are largely protected from predation because they resemble monarch butterflies (very distasteful). Batesian mimicry is usually a successful strategy as long as the model and mimic are found in the same location, the mimic's population size is smaller than that of the model, and predators associate the model's appearance with an unpleasant effect.In 1879, Fritz Müller recognized that two or more distasteful species often share the same aposematic color patterns. Many species of wasps, for example, have alternating bands of black and yellow on the abdomen. This defensive tactic, commonly known as Müllerian mimicry, benefits all members of the group because it spreads the liability for "educating the predator" over more than one species.
Describe and give an example of each of four ways that insects use to communicate with each other.
Some insects can't see very well, and some live in dark places, so they need a method of communication that doesn't depend on sight. They have to do something that another bug can feel. When an ant is 'following a leader,' it uses its antennae to tap the leader's legs so the lead ant knows that its follower is keeping up with it. Other bugs send vibrations through the plant they are on to warn each other of approaching danger.
Insects have an incredible sense of smell. They can detect just a few molecules of a certain scent in the air. To communicate by smell within a species, insects release chemicals called pheromones. These special chemicals do many things, including marking trails and attracting mates. An ant who finds a food source leaves a pheromone trail as it heads back to the colony. As other ants come across the trail they follow it to the food source and leave another layer of pheromone on their way back. This makes the trail stronger and attracts even more ants. Sometimes pheromones are released into the air, and insects smell them with their antennae. Other times they are released onto something - like a leaf or another insect - in which case the insect can taste the chemical with its feet.
From the buzzing of a bee to the whine of a mosquito to a cricket's chirp, insects can make lots of sounds. Many times, these sounds are higher than human ears can hear. Insects can hear them with sensitive membranes called tymbals located on their abdomen or legs. Here are a few of the ways that insects make their own sounds. Bugs like crickets and grasshoppers make sound by rubbing one part of the body (like a leg) against another (maybe a wing). This is called stridulation. You can think of it as kind of like playing a violin. Some insects, including cicadas, can make a very loud sound by vibrating a membrane on their body (their tymbal). A hollow part of their body cavity acts as a resonance chamber to amplify the sound. This works like a drum. Most insects breathe through tiny pores called spiracles. Some of them use these spiracles to make sounds, too. The Madagascar Hissing Cockroach, for example, pushes air out of its spiracles very fast to make a hissing sound. Bees and mosquitoes buzz when they fly because their wings vibrate fast enough to produce a sound.
Insects have compound eyes, made up of thousands of tiny lenses instead of just one like we have. These lenses don't allow them to see very clearly, but they do make them highly sensitive to light and movement. When you sneak up behind a fly with the fly swatter, chances are it'll see your movement and get out of the way before you can smash it! Insects communicate visually in a passive way by their colorings and markings. After eating the poisonous Monarch butterfly, for example, predators avoid its orange and black coloring. The Viceroy butterfly looks almost identical to a Monarch, so predators avoid it too, even though it is safe to eat. Some moths have a different way of scaring off predators - they have marks on their wings that look like big eyes, threatening would-be attackers.
What castes are found in honey bees and in termites, and what is the function of each?
Caste, in biology, a subset of individuals within a colony (society) of social animals that is specialized in the function it performs and distinguished by anatomical or morphological differences from other subsets.
-The queen bee is the heart and soul of the colony. She is the reason for nearly everything the rest of the colony does. The queen is the only bee without which the rest of the colony cannot survive. Without her, your hive is sunk. A good quality queen means a strong and productive hive.
Only one queen lives in a given hive. She is the largest bee in the colony, with a long and graceful body. She is the only female with fully developed ovaries. The queen's two primary purposes are to produce chemical scents that help regulate the unity of the colony and to lay eggs — and lots of them. She is capable of producing more than 1,500 eggs a day at 30-second intervals. That many eggs are more than her body weight!
-The majority of the hive's population consists of worker bees. Like the queen, worker bees are all female. Workers are smaller than the queen, their abdomens are shorter, and on their hind legs they possess pollen baskets, which are used to tote pollen back from the field. Like the queen, the worker bee has a stinger. But her stinger is not a smooth syringe like the queen's. It has a barb on the end. The barb causes the stinger, venom sack, and a large part of the bee's gut to remain in a human victim. Only in mammals does the bee's stinger get stuck. The bee can sting other insects again and again while defending its home.
-The only male bee in the colony, drones make up a relatively small percentage of the hive's total population. At the peak of the season their numbers may be only in the hundreds. You rarely find more than a thousand. He is larger and stouter than a worker bee. But his shape is in fact more like a barrel (the queen's shape is thinner, more delicate and tapered). The drone's eyes are huge and seem to cover his entire head. He doesn't forage for food from flowers, and he has no pollen baskets. He doesn't help with the building of comb, because he has no wax-producing glands. Nor can the drone bee help defend the hive — he has no stinger and can be handled by the beekeeper with absolute confidence. An organ inside the queen called the "spermatheca" is the receptacle for the sperm. The queen will mate with several drones during her nuptial flight. After mating with the queen, the drone's most personal apparatus is torn away, and it falls to its death.
-Each termite lives in a nest or colony with hundreds, thousands, or even millions of its brothers and sisters. In fact, the termite colony is really a large, extended family. Within this family, various groups of individuals have different functional roles according to a "caste system". The worker caste is the largest group. It consists entirely of immatures, both males and females. These soft-bodied, wingless individuals perform all of the hard labor in the colony: they clean, maintain, and repair the nest, gather food and water, care for the young, and construct new tunnels and galleries as the colony grows. These juveniles all have the genetic capacity to undergo additional molts and become soldiers or reproductives, but most will spend their entire lives as workers.
-Members of the soldier caste are larger in size but fewer in number than the workers. They are also wingless, but they have large heads with powerful jaws. Their job is to guard the nest site and protect it from attacks by ants or other invaders. In some species the soldiers lack jaws but have a large gland in the head that shoots defensive chemicals through a nozzle at the front of the head. The soldiers are unable to care for themselves so they must be fed and groomed by the workers.
-The reproductive caste always includes a king (male) and a queen (female) who are the parents of the termite family and founders of the colony. Some species also have a few supplemental reproductives who share the egg laying duties. These are the only adult insects in the colony. The queen lays large numbers of eggs which develop into more workers and soldiers as the family grows. In every mature colony, there also develops an annual population of young winged reproductives that swarm from the parent nest for a short mating flight. After flight, the delicate wings break off, and the new king and queen set out to find another nest site and start a new colony. Large colonies with multiple reproductives may also split into two or more daughter colonies, a process known as "budding".
The termite's caste system is regulated by pheromones. The king and queen each produce special pheromones that circulate throughout the colony and inhibit workers of the same sex from molting into reproductive adults. A death in the royal family (or an increase in the size of the colony) results in a lower concentration of the corresponding pheromone and, subsequently, one or more workers will molt into replacement reproductives. Likewise, the concentration of sex-specific soldier pheromones regulate the numbers of male and female soldiers to fall within an optimal range based on colony size. Excess numbers of soldiers or reproductives may be killed and eaten by the workers.
Name several ways in which insects are beneficial to humans and several ways they are detrimental.
Beneficial: they pollinate crops(honeybee, butterfly), are predators of pest(spiders, beetles), they produce things like silk or honey, they are scavengers (ants, beetles, and cockroaches thrive on dead carcasses, left over organic matter or excreta and in the process clean the environment)
Detrimental: Pest of agriculture (caterpillars, locust), are household pest (Beetles, termites), they spread disease (mosquito)
In what ways are detrimental insects controlled? What is integrated pest management?
Pesticides are the only toxic substances released intentionally into our environment to kill living things. This includes substances that kill weeds (herbicides), insects (insecticides), fungus (fungicides), rodents (rodenticides), and others. The use of toxic pesticides to manage pest problems has become a common practice around the world. Pesticides are used almost everywhere -- not only in agricultural fields, but also in homes, parks, schools, buildings, forests, and roads. It is difficult to find somewhere where pesticides aren't used -- from the can of bug spray under the kitchen sink to the airplane crop dusting acres of farmland, our world is filled with pesticides. In addition, pesticides can be found in the air we breathe, the food we eat, and the water we drink.
Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and nontarget organisms, and the environment.
What is a plausible scenario for evolution of wings and flying insects?
Derived from aquatic/juvenile-aquatic insects that bore external gill winglets on their thorax from which wings could have been derived
These winglets were apparently movable and articulate; capable of swimming movements
Selectively evolved larger for more surface area = better temperature control/faster swimming
Set the stage for the evolution of a functional wing with neuromuscular control
Describe three different types of mouthparts found in insects, and tell how they are adapted for feeding on different foods.
-Chewing insects have two mandibles, one on each side of the head. The mandibles are positioned between the labrum and maxillae. They are typically the largest mouthparts of chewing insects, being used to masticate (cut, tear, crush, chew) food items. They open outwards (to the sides of the head) and come together medially. In male stag beetles, the mandibles are modified to such an extent that they do not serve any feeding function, but are instead used to defend mating sites from other males. In ants, the mandibles also serve a defensive function (particularly in soldier castes). In bull ants, the mandibles are elongate and toothed, used as hunting (and defensive) appendages. In bees, which feed primarily by use of a proboscis, the primary use of the mandibles is to manipulate and shape wax, and many wasps have mandibles adapted to scraping and ingesting wood fibres.
-Situated beneath the mandibles, paired maxillae manipulate food during mastication. Maxillae can have hairs and "teeth" along their inner margins. At the outer margin, the galea is a cupped or scoop-like structure, which sits over the outer edge of the labium. They also have palps, which are used to sense the characteristics of potential foods.
-The labium is a quadrupedal structure, although it is formed from two fused secondary maxillae. It can be described as the floor of the mouth. With the maxillae, it assists manipulation of food during mastication or chewing or, in the unusual case of the dragonfly nymph, extends out to snatch prey back to the head where mandibles can eat. In the honey bee, the labium is elongated to form a tube and tongue, and these insects are classified as having chewing and lapping mouthparts.
-The hypopharynx is a somewhat globular structure, arising from the base of the labium. It assists swallowing.
-This section deals only with sucking insects, not those that pierce prior to sucking. The typical example is the moths and butterflies, although as is always the case with insects, there are variations. Some moths have no mouthparts at all. All but a few adult Lepidoptera lack mandibles (the mandibulate moths have fully developed mandibles as adults), with the remaining mouthparts forming an elongated sucking tube, the proboscis. The proboscis is a long tube that is formed by heavily modified maxillae, specifically the galea.
Piercing and sucking
-A number of insect orders (or more precisely families within them) have mouthparts that pierce food items to enable sucking of internal fluids. Some are herbivorous, like aphids and leafhoppers, while others are insectivorous, like assassin bugs and mosquitoes (females only). The defining feature of the order Hemiptera is the possession of mouthparts where the mandibles and maxillae are modified into a proboscis, sheathed within a modified labium, which is capable of piercing tissues and sucking out the liquids. For example, true bugs, such as shield bugs, feed on the fluids of plants. Predatory bugs such as assassin bugs have the same mouthparts, but they are used to pierce the cuticles of captured prey. In female mosquitoes, all mouthparts are elongate. The labium encloses all other mouthparts like a sheath. The labrum forms the main feeding tube, through which blood is sucked. Paired mandibles and maxillae are present, together forming the stylet, which is used to pierce an animal's skin. During piercing, the labium remains outside the food item's skin, folding away from the stylet. Saliva containing anticoagulants, is injected into the food item and blood sucked out, each through different tubes.
-The housefly is the typical sponging insect. The labium gives the description, being articulate and possessing at its end a sponge-like labellum. Paired mandibles and maxillae are present, but much reduced and non-functional. The labium forms a proboscis which is used to channel liquid food to the oesophagus. The housefly is able to eat solid food by secreting saliva and dabbing it over the food item. As the saliva dissolves the food, the solution is then drawn up into the mouth as a liquid. The labellum's surface is covered by minute food channels, formed by the interlocking elongate hypopharynx and epipharynx, which form a tube leading to the oesophagus. The food channel draws liquid and liquified food to the oesophagus by capillary action.
Describe the physiology of malpighian tubules.
Malpighian tubules remove wastes from insects by producing urine and solid nitrogenous waste, which are then excreted from the body.
Malpighian tubules are found in the posterior regions of insects, where they work with glands in the rectum to excrete waste and maintain osmotic balance.
Ions are transported through active pumps found in the malpighian tubules; as the ions are secreted, water and waste are drawn to the tubules due to the change in osmotic pressure.
Nitrogenous wastes, such as uric acid, are precipitated as thick pastes or powder to be excreted.
Describe the physiology of the tracheal system in insects. How does this system relate to the circulatory system in insects? What adaptations do insects have that make the use of respiratory pigments unnecessary or of less value? Make sure to accurately describe insect respiration in your discussion.
Tracheae open to the outside through small holes called spiracles. The spiracles can act as muscular valves in some insects. The network of tracheae equalized pressure throughout the system.
Gas exchange occurs at the cellular level; no need for respiratory pigment because the tracheoles that carry fresh air come in direct contact with almost every cell.
The circulatory system functions in oxygen transport in some aquatic immature insects; hemolymph consists of plasma and amebocytes for lymphatic system and immune/cellular house keeping. Body parts are bathed in hemolymph.
Insects have a unique respiratory system that is separated from the circulatory system. This respiratory system is composed of slender tracheae that enter the hemocoel from spiracles. Insects have an open circulatory system meaning that blood and interstitial fluids move freely throughout the hemocoel, not in vessels that reconnect to the heart. This system typically causes organisms to have bursts of movement followed by oxygen deprovation. Insects counter this by the means of a separate tracheal system in which oxygen flows in through the spiracles into slender tracheal tubes. These tracheal tubes function like air ducts in a house, starting from being relatively large, and becoming more slender as they spread throughout the hemocoel. This eventually leads to capillary like endings called tracheal end cells which are fluid filled cells at the end of the trachea. These transport oxygen directly to the surrounding tissue, thus providing a constant flow of oxygen to the tissue. This allows insects to have incredibly high endurance for example houseflies are able to beat their wings non stop 24/7 and turn upside down and beat their wings until they starve to death.
What appendages are characteristic of chelicerates?
Unusually for arthropods, they have no antennae. Usually, six pairs of appendages occur on the six segments of the prosoma. The first pair (at the anterior, i.e. 'head end') is distinctive, and forms the chelicerae (for which the group is named). The chelicerae are often modified into claw-like structures. They are followed by the pedipalps, which are also commonly modified. Depending on the group, the chelicerae and pedipalps may be modified for feeding, sensing, defence, reproduction or locomotion. The remaining four pairs of appendages on the prosoma are usually modified for walking.
Briefly describe the distinguishing morphological features of each of the following: eurypterids, horseshoe crabs, pycnogonids.
Eurypterids - extinct; giant water scorpions; 3m in lenth; spike like telson, large crushing claws; lived in marshy habitats; crawled on land for short distances
-Xiphosura aka Horseshoe crabs - unsegmented carapace; long point telson; book gills; hinged between cephalothorax and abdomen; crustaceans; did well 400 mya as organisms began to move on land (Debonian); gestation of eggs is in a tidal cycle; move in on highest tide of the month, plant eggs in sand and cover them, then ride back out; 28 days later, the babies hatch and release into the water; what comes out of the egg is called a trilobite larva; over time grows and feeds; successful strategy; only 4 or 5 species compared to so many, years ago. Limulus (Atlantic horse shoe crab) are successful due to sandbar stability.
-Pycnogonida - Sea spiders can get very large (70inches); sort of live like the tick like existence except life on Cnidarians, clams and starfish as well; stick proboscis in the organism and feed; overall in most organisms in the world the parents do not usually protect the eggs but females are primary or evolved; seahorse and sea spiders males are the primary role in reproduction; females live for multiple years; females release all of her eggs at one time; males with as many mates as they can; males glue the eggs on the arms or ovitures and carry them; sometimes 15-20 egg masses; larval stage is...; sea spiders have an epistostoma abdomen which is smaller than land spiders which have a larger abdomen that carries most of the organs.
What are the tagmata of arachnids, and which tagmata bear appendages?
Arachnids have two stagmata the prosoma (cephalothorax) and opisthosoma (abdomen); meaning the after-part of the body; it is the compound body section resulting from fusion of segments.
Prosoma bear all appendages
Describe the mechanism of each of the following with respect to spiders: feeding, excretion, sensory reception, web-spinning, reproduction.
Feeding - fangs inject venom with digestive enzymes that liquefy prey's tissues, which are then sucked through chelicerae
-Sensory reception - 8 simple eyes; used to detect movement, some may form images; rely largely on cuticular mechanoreceptors (sensory setae) that detect vibrations or air movements
-Excretion - use of Malpighian tubules; work with reabsorbtive cells in the intestinal epithelium which recapture potassium
-Web spinning - silk glands secrete a scleroprotein that hardens to form silk thread; stronger than steel threads; spin webs for various purposes
-Reproduction - courtship ritural; male spins small web, deposits a drop of sperm on it, carries sperm on pedipalps to genital opening on female; female lays eggs in silken net
What are the most important spiders in the United States that are dangerous to humans? How does their venom work?
Black widow - more systemic, general inflammation around the body, mild diarrhea, pain at site of wound; meter readers are more susceptible to black widows; rarely come in the home; solitary; females are more of a threat; venom is neurotoxic; acting on nervous system and affects breathing, muscle contraction, heart pumping; 5/1000 bites are fatal
- Brown recluse - by far the most risk to health; brown recluse are in the homes; find the moults of the shells; sinks or bathtubs; stay in places that are moist; reclusive spider; shoes or clothes on the ground left overnight, brown recluse hides in clothes, feels threatened and bites; cause selling and lead to necrosis; venom causes necrosis and splitting of tissue; antibiotics are given to avoid secondary infection; venom is hemolytic.
-Hobo spider is found throughout the Pacific Northwest. It is large and brown with a distinct pattern of yellow markings on its abdomen. Unlike many other similar looking spiders, hobo spiders do not have dark bands on their legs. To catch their prey, hobo spiders build funnel webs in holes, cracks, and recesses. They may be found in outdoor workplaces with retaining walls, and in foundations, window wells, and stacks of firewood and bricks. Indoors, they can nest between boxes or other storage items, on window sills, under baseboard heaters or radiators, behind furniture, and in closets. Hobo spiders do not climb like most spiders but are fast runners. These spiders are much more likely to attack if provoked or threatened. The bite of a hobo spider may go unnoticed; however a moderate to severe, slow-healing wound will develop.
Distinguish each of the following orders from each of the following orders from each other: Araneae, Scorpiones, Opiliones, Acari.
Aranea - spiders; average cephalothorax, large thick abdomen; small pedipalps and chelicerae
Scorpiones - scorpions; short cephalothorax; long preabdomen; long slender post abdomen that ends in a stinging apparatus; small chelicerae but large pedipalps act as pinchers
Opiliones - daddy longlegs; small, rounded tagmata with long legs; only arachnids with penis besides mites
Acari - ticks and mites; mostly very small; complete fusion of cephalothroax and abdomen, no segmentation; mouthparts carried on a small anterior projection called a capitulum.
You are given a large tropical millipede to raise in a humid terrarium lined with soil and leaf litter. What should you feed it?
The millipede will eat the leaf litter/ decayed plant material; sometimes eat living plants
Define the following: trilobites, horseshoe crabs, chelicerate, mandibles, pedipalp, eurypterids, sea spiders, ovigers, protonymphon, green glands, Malpighian tubules, gills, antennae, telson, biramous, coxal glands, Acari, chitinous exoskeletons, abdomen, myriapod, cephalothorax, biramous, Arthropoda, millipedes, entomology, book lungs, tracheae, Uniramia.
trilobite - an extinct marine arthropod that occurred abundantly during the Paleozoic era, with a carapace over the forepart, and a segmented hind part divided longitudinally into three lobes.
-Horseshoe crab - a large marine arthropod with a domed horseshoe-shaped shell, a long tail-spine, and ten legs, little changed since the Devonian.
-Chelicerate - an arthropod of the large group Chelicerata; an arachnid, sea spider, or horseshoe crab.
- mandibles - the jaw or a jawbone, especially the lower jawbone in mammals and fishes; half of the crushing organ in an arthropod's mouthparts.
-pedipalps - each of the second pair of appendages attached to the cephalothorax of most arachnids. They are variously specialized as pincers in scorpions, sensory organs in spiders, and locomotory organs in horseshoe crabs.
- Eurypterids - an extinct marine arthropod of a group occurring in the Paleozoic era. They are related to horseshoe crabs and resemble large scorpions with a terminal pair of paddle-shaped swimming appendages.
- sea spider - a spiderlike marine arachnid that has a narrow segmented body with a minute abdomen and long legs.
- ovigers - In Pycnogonida, one of a pair of legs, located behind the palps and in front of the walking legs, used for grooming and, in the male, for carrying eggs. In females of some species the ovigers are reduced or absent.
- protonymphon - second instar in mites; early nymph instart of arthropod lifecycle
- green gland - excretory antennae gland in some Crustaceans
- Malpighian tubule - a tubular excretory organ, numbers of which open into the gut in insects and some other arthropods.
- gills - aquatic arthropods respire with these
- antennae - either of a pair of long, thin sensory appendages on the heads of insects, crustaceans, and some other arthropods.
- telson - the last segment in the abdomen, or a terminal appendage to it, in crustaceans, chelicerates, and embryonic insects.
- biramous - appendages with two distinct branches
- coxal glands - modified nephridia that opens at the base of the first and third walking leg
- acari - ticks and mides order of arachnida
- chitinous exoskeletons - A tough, semitransparent substance that is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects. Chitin is also found in the cell walls of certain fungi and algae.
- abdomen - the posterior part of the body of an arthropod, especially the segments of an insect's body behind the thorax.
- myriapod - centipede or millipede; many legs
- cephalothorax - the fused head and thorax of spiders and other chelicerate arthropods.
- Arthropoda - phylum with chitin exoskeleton; an invertebrate animal of the large phylum Arthropoda, such as an insect, spider, or crustacean.
- millipede - a myriapod invertebrate with an elongated body composed of many segments, most of which bear two pairs of legs. Most kinds are herbivorous and shun light, living in the soil or under stones and logs.
- entomology - study of insects
- book lungs - respiratory structure of chelicerates where many thinwalled air pockets extend into a blood filled chamber in the abdomen
- tracheae - any air tube of insects
- uniramia - uniramous arthropod subphylum
Discuss the economic and medical importance of members of order Acari to human well-being.
Economic importance - damage many types of crops which in turn cost money
Medical importance - can carry many diseases and allergic reactions to bites
Why are horseshoe crabs in the same subphylum as spiders?
There are two tagmata; 6 pairs of cephalothorax appendages, two of which are chelicerae mouthparts
Spiders and insects have an excretory system composed of what?
How do spiders eat? Spiders breathe by means of what?
Nearly all spiders subdue their prey by injecting venom through their fangs, which operate much like a pair of hypodermic needles. Besides the paralytic action of the venom compounds, the spider regurgitates digestive fluids onto the prey to digest it, working more or less like a meat tenderizer. Once the prey begins to liquefy, the spider uses its jaws and pedipalps to further masticate its meal. The "meat ball" is then slowly imbibed by the mouthparts, taken in mostly in liquid form. Spiders in the obscure family Uloboridae do not possess venom glands, but the rest of the feeding process remains the same. Prey is subdued by tightly wrapping it in silk.
Describe scorpion mating.
The males need to be stealthy, strong, and quick; typically seen as food to females, sex then eaten; males dance by grabbing on to her claws; stinger isn't as quick as most think, plant front legs and then swing the stinger over the head; male grabs females claws and retreat, female pushes forward, male deposits sperm mass on ground and tries to line up the spermatophore with the female, male thrusts forward forcing the female to crack the sperm mass hoping the sperm fertilize the female, male runs away; when fertilized the babies climb on the mothers back, if fall off moms do not recognize the baby as their own anymore and may eat it.
Scorpions have their own special mating ritual in which the male will use his pinchers to grab the female's pinchers and pull her along in what can only be classified as a "courtship dance". In some species the male will even sting the female, however, this does not cause her any harm. During this "dance" the male will drag the female along the ground until he has found a good spot to lay his seeds (usually on a twig or rock). After the male has lain his seeds, he will then drag the female through them and she will secrete them into her body through an opening in her abdomen.
The eggs will stay within the female for several months to a year depending upon species. The young are born live and fall into the mother's legs which she especially folds up for this occasion, creating a sort of basket and means for them to climb up to her back. A female Scorpion carries her babies (usually 25-35) on her back for 10 to 15 days before they go off on their own and are fully independent.
Diagram and explain the phylogeny of arthropods. Make sure to include a feature or two between each branch and node of the cladogram. Make sure to include each subphyla and significant classes. Also include the outgroups; tardigrades and onychophorans.
There are over ¾ of a million species in the class ______________________.
Grub like myriapods that live in leaf mold and have no heart or tracheae are called _________________________.
The "poison claws" of centipedes are called _____________________.
Xiphosurians have a larva called a _____________________ larva.
Male pycnogonids brood eggs on specialized appendages called __________________.
Pycnogonids have a __________________________ larva.
Arachnids have an epicuticle with high ______________ content to reduce water loss.
Fill in the name of the class by each common name.
________2________ seed shrimp
1. Water Fleas/Class Branchipoda
2. Seed Shrimp/Class Ostracoda
3. Barnacles/Scientific name: Cirripedia/Class Crustacea
4. Crab/Class Malcostraca
Recommended textbook explanations
Miller and Levine Biology
Joseph S. Levine, Kenneth R. Miller
Biology Study Guide
Biology The Dynamics of Life
Modern Biology: Student Edition
Janet L. Hopson, Postlethwait
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