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GRADE 11: BIOLOGY 2 (ANIMAL BIOLOGY) M1-B

Terms in this set (45)

Animal Morphoanatomy
Morphoanatomy - The study of anatomical forms and structures with emphasis on characteristics useful in distinguishing the species
Bilateral Symmetry
Divides an organism into mirror image halves
-EX. Linckia laevigata, Felis domesticus, Beetle
Radial Symmetry
The organism can be divided into similar halves by passing a plane at any angle along a central axis
-EX. Tripneustes ventricosus, Linckia laevigata, Coral Polyp
Asymmetry
Not identical on both sides of a central line; unsymmetrical; lacking symmetry
-EX. Leucosolenida botryoides, Clathrina clathrus, sponges
SPONGES (Phylum Porifera)
• Marine
• tiny pores
• 3 main parts: ostia, osculum, spongocoel.
• Asymmetrical
Phylum Cnidaria
• jellyfish, box jellyfish, hydras, corals, sea anemones.
• radial symmetry
• endoderm and ectoderm
• stinging cells
FLATWORMS (Phylum Platyhelminthes)
• Body is flattened (because of the lack of coelom)
• Has definitive head and tail region; eyespots in head and has thick cuticle outside the body.
• May be free-living or parasitic
ROUNDWORMS (Phylum Nematoda)
• Body is long, smooth, and unsegmented.
• Cylindrical bodies are tapered at both ends.
• Free-living or parasitic
SEGMENTED WORMS (Phylum Annelida)
• Body is segmented internally and externally;
• complete digestive system;
• tube within a tube body plan.
• Most are free-living
• earthworm, leech
Phylum Mollusca (Mollusks)
• soft, unsegmented and has strong muscular foot (in snail). Shell can be external (in snails and shellfish) or internal (in octopus).
• mantle, muscular foot, visceral mass
• snails, shellfish, oysters, clams, octopus, squids, cuttlefish, scallops
Phylum Echinodermata (Echinoderms)
• spiny surface, with an internal skeleton inside their body.
• tube feet
• sea stars, sea cucumbers, sea urchins, brittle stars, sea lilies
Phylum Arthropoda (Anthropods)
• largest of the phyla of the kingdom Animalia
• insects, crustaceans, arachnids, centipedes, millipedes, spiders, scorpions
Phylum Chordata (Chordates)
• Nerve cord, Notochord, Pharyngeal slits, Postanal tail, Segmentation
• fishes, amphibians, reptiles, birds mammals
Asexual reproduction
- individuals are exact clones of the parent with identical genetic makeup
- Regeneration, Budding, Parthenogenesis
Regeneration
• Involves the production and differentiation of new tissues to replace missing and damaged parts of the body.
• Cellular replication by mitosis, followed by differentiation
Budding
• Involves forming of new individual from an outgrowth or 'bud' on the parent's body.
• It doesn't involve any sex organs.
• Hydra and polyps (cnidarians and sponges)
• If not detached from parent's body, it might grow into a colony
Parthenogenesis
• Involves an activated unfertilized egg that undergoes mitosis in the absence of cytokinesis
• Two nuclei fuse together to form 2n nucleus then further develop as if it had been fertilized.
• E.g., aphids (Aphididae), bees (Apidae), wasps (Vespidae) and ants (Formicidae), few species of vertebrates e.g., Bynoe's gecko (Heteronotia binoei)
Sexual reproduction
individuals are formed from the combination of n gametes to form a genetically unique offspring (variety)
ISOGAMY (Form of Sexual Reproduction)
• similar gametes
• male and female gametes are not distinguishable
• both gametes are either motile or immotile
ANISOGAMY (Form of Sexual Reproduction)
• dissimilar sizes
• male and female gametes are present
• both gametes are either motile or immotile
OOGAMY (Form of Sexual Reproduction)
• large immotile female gametes with small motile male gametes
• male and female gametes are present
• egg cell = immotile; sperm = motile
Monoecious (Monoecism/Hermaphroditic)
Having male and female sex organs in the same individual
Dioecious (Dioecism)
Having male reproductive organs in one individual and female in another
Self-Fertilization
Fertilization effected by union of egg cell and sperm cell from the same individual.
Cross-Fertilization
Fertilization in which gametes are produced by separate individuals or sometimes by individuals of different kinds
Sequential hermaphroditism
• occurs when the individual changes sex at some point in its life.
• Protandry (male to female)
• Protogyny (female to male)
Indirect development
• Involves one or more intermediate larval forms before the adult form is attained.
• Occurs mostly in invertebrates
• Metamorphosis present
• butterfly and frogs
Direct development
• Offspring hatch or are born in miniature adult form.
• Occurs mostly in vertebrates
• Metamorphosis absent
• dogs and humans
Gonads
• Sex organs (Both male and female)
• Produce hormones that regulate the development of gametes and secondary sex organs act as pheromones and produce sexual differences in appearance and behavior.
Spermatogenesis
• Testes; testosterone
• produces spermatozoa from PGC by way of mitosis and meiosis.
Oogenesis
• Ovaries; estrogen
• produces oogonia from PGC by way of mitosis and meiosis.
NERVOUS SYSTEM
• allows body to respond quickly to changes in the environment by gathering information, transmitting, and processing information to determine the best response, and sending information to muscles, glands, and organs so they can respond correctly.

CNIDARIAN
• In Hydra, nerve nets are diffused all over the body to control the contraction of the gastrovascular cavity or the gastrocoel.

FLATWORM (PPLANARIA/PLATYHELMINTH)
• CEPHALIZATION - the onset of cephalization marks a more complex nervous system
• In simple cephalized animals (ex: Planaria) a simple central nervous system or CNS with a small brain and longitudinal nerve cords is present.

ANNELIDS AND ANTHROPODS
• In more complex invertebrates like annelids and arthropods, the nervous system is divided into two regions: the CNS and PNS.
• CNS or Central Nervous System is composed of brain and ventral nerve cords with clusters of neurons called ganglia.
• The rest of the nerves in animal's body is the PNS or peripheral nervous system.

HUMAN
• Central (Brain and Spine) and
• Peripheral (Cranial and Spinal Nerves)
1. Somatic Nervous System (voluntary)
- Relays information from skin, sense organs & skeletal muscles to CNS
- Brings responses back to skeletal muscles for voluntary responses
2. Autonomic Nervous System (involuntary)
- Regulates bodies involuntary responses
- Relays information to internal organs
- Two divisions:
A. Sympathetic nervous system - in times of stress
➢ Emergency response
➢ Fight or flight
B. Parasympathetic nervous system - when body is at rest or with normal functions; Normal everyday conditions

• Basic Cells of the Nervous System:
- Parts of a Neuron
1. Dendrite - receive stimulus and carries it impulses toward the cell body
2. Cell Body with nucleus - nucleus & most of
cytoplasm
3. Axon - fiber which carries impulses away from cell body
4. Schwann Cells- cells which produce myelin or fat layer in the PNS
5. Myelin sheath - dense lipid layer which insulates the axon - makes the axon look gray
6. Node of Ranvier - gaps or nodes in the myelin sheath
- Impulses travel from dendrite to cell body to axon

• Three types of Neurons
o Sensory neurons - bring messages to CNS
o Motor neurons - carry messages from CNS
o Interneurons - between sensory & motor neurons in the CNS
IMMUNE SYSTEM
• responsible for defending organisms from pathogens such as:
✓ Viruses: Ebola, rabies, HIV, HPV
✓ Bacteria: E. coli, Salmonella, Staphylococci
✓ Fungi: Trichophyton, Candida
✓ Systemic: cancer cells

• Innate immunity
- Nonspecific response to a broad range of microbes
- Formed by skin and mucous membrane accompanied by macrophages and other phagocytic cells

• Acquired immunity
- Lymphocyte provides specific defense against pathogens.
- The body detects antigen, which is either: a foreign object, molecule or invading pathogens.
- The immune system now will produce antibodies: which will attach to the antigens.
SKELETAL SYSTEM
• support the body, protect internal organs, and allow for the movement of an organism.
• hydrostatic skeleton, exoskeleton, and endoskeleton.

• HYDROSTATIC SKELETON
- fluid-filled compartment
- coelom
- hydrostatic pressure
- sea anemones, earthworms, Cnidaria, and other invertebrates (soft-bodied animals)

• EXOSKELETON
- external, hard, encasement on the surface of an organism.
- shells of crabs and insects
- defense against predators, supports the body, and allows for movement
- chitin
- calcium carbonate

• ENDOSKELETON
- consists of hard, mineralized structures located WITHIN the soft tissue of organisms
- human and horse bones
- support for the body, protect internal organs, and allow for movement
MUSCULAR SYSTEM
• controls numerous functions, which is possible with the significant differentiation of muscle tissue morphology and ability.
• Skeletal Muscle Tissue, Cardiac Muscle Tissue, Smooth Muscle Tissue

• Skeletal Muscle Tissue
-attaches to the skeletal system via tendons to maintain posture and control movement.
-voluntary

• Cardiac Muscle Tissue
-found only in the heart
-involuntary

• Smooth Muscle Tissue
-digestive system and respiratory system
-non-striated and involuntary.
DIGESTIVE SYSTEM
• break down large, complex molecules to small, simpler molecules absorbable by cells
• Animals are heterotrophic

• Invertebrate Digestive Systems GASTROVASCULAR CAVITY (GVC)
- Platyhelminthes and Cnidaria
- digest their food a tube or cavity with only one openingthat serves as both mouth and anus
• Invertebrate Digestive Systems (ALIMENTARY CANAL_
-earthworms (Annelida: Oligochaeta) and insects (Arthropoda: Insecta)
-pathway which receives food through mouth on one end and eliminates wastes through the anus on another.

• Vertebrate Digestive Systems
RESPIRATORY SYSTEM
• consists of organs that allow gas exchange. It brings oxygen in the body cells of animals and eliminates carbon dioxide, which is a waste product of cells

• Fish and other aquatic organisms use their gills to take up oxygen dissolved in the water and diffuse CO2 out of the bloodstream.

• Instead of lungs, insects breathe with a network of tiny tubes called tracheae. Air enters the tubes through a row of holes along an insect's abdomen called spiracles. The air then diffuses down the blind-ended tracheae. The tracheoles are the sites of gas exchange.

• When inhaling, there is a decrease in pressure around the lungs, causing air to breathe in. The ribcage expands and moves the diaphragm downward.• When exhaling, there is an increase in pressure around the lungs and force air out of the respiratory tract. The ribcage contracts and moves the diaphragm upward.
CIRCULATORY SYSTEM
composed of heart, blood vessels, and blood.
EXCRETORY SYSTEM
provides a mechanism for the elimination of various wastes from the body
ENDOCRINE SYSTEM
collection of glands that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things
Hormones
chemical substances produced by endocrine gland. They are transported into the circulatory system to target organs where they exert their functions.
HOMEOSTASIS
• tendency for an organism or cell to maintain a constant internal environment within tolerance limits.

Internal equilibrium is maintained by adjusting physiological processes, including
• Body temperature (normally between 36-38°C)
• Carbon dioxide concentration (normally 35-45 mmHg)
• Blood pH (normally between 7 35-745)
• Blood glucose levels (normally 75-95 mg/dL)
• Water balance (varies depending on individual body size)

Homeostatic mechanisms operate via a feedback loop that may involve either the nervous or endocrine systems (or both)
• When specialized receptors detect an internal change to conditions, a response is generated to correct the change
• Most homeostatic responses involve an effect that is antagonistic to the detected stimulus (negative feedback)
• When levels return to equilibrium, the effector ceases to generate a response, and an internal balance is therefore maintained
• if physiological condition moves outside of tolerance limits, the disease will occur as a consequence

• Homeostasis does not involve keeping conditions static it involves keeping conditions within tightly regulated
physiological tolerance limits.
Homeostatic processes are controlled by negative feedback and hence these systems
occur more commonly within the body
TRUE
NEGATIVE FEEDBACK
• involves a response that is the reverse of the change detected (it functions to reduce the change)

• A change is detected by a receptor and an effector is activated to induce an opposite
effect this promotes equilibrium

Examples of processes that utilize negative feedback loops include homeostatic
systems, such as:
• Thermoregulation (If body temperature changes, mechanisms are induced to restore
normal levels)
• Blood sugar regulation (insulin lowers blood glucose when levels are high: glucagon raises blood glucose when levels are low)
• Osmoregulation (ADH is secreted to retain water when dehydrated and its release is
inhibited when the body is hydrated)
POSITIVE FEEDBACK
• involves a response that reinforces the change detected (it functions to amplify the change)

A change is detected by a receptor and an effector is activated to induce the same effect-this promotes further change

Positive feedback loops will continue to amplify the initial change until the stimulus is removed

Examples of processes that utilize positive feedback loops include
• Childbirth - stretching of uterine walls cause contractions that further stretch the walls (this continues until birthing occurs)
• Lactation-the child feeding stimulates milk production which causes further feeding (continues until the baby stops feeding)
• Ovulation- the dominant follicle releases estrogen which stimulates LH and FSH release to promote further follicular growth
• Blood clotting- platelets release clotting factors which cause more platelets to aggregate at the site of injury
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