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from Mr. Hopkin's class

Vegetative propagation

a form of asexual reproduction in which plants produce offshoots that are clones of themselves, which then develop into independent mature plants.


the male gametophyte of gymnosperms and angiosperms.


any of the muscular, ring like regulatory valves along the digestive tract, which control the passage of materials through the alimentary canal.

Vascular cambium

The continuous cylinder of meristematic cells that surrounds the xylem and pith of a plant, which gives rise to secondary xylem and phloem.


The top, sticky part of a plant's carpal, which traps pollen grains from the air.


The continuous production of haploid sperm cells through meiosis in the testis of the human male.


an embryonic leaf in the angiosperm seed; monocots have one cotyledon and dicots have two cotyledons.

Refractory period

the short period just after an action potential has occurred in which a neuron cannot respond to another stimulus; this is due to a sudden increase in the permeability of the membrane to potassium ions.


the hormone secreted by the ovaries that prepares the uterus for implantation of the embryo and helps to maintain the pregnancy.


a usually green structure that is a modified leaf in angiosperms. Sepals enclose and protect the flower bud before it opens.


estrogens are the female sex hormones, which are produced in the ovaries by the developing follicle during the first half of the menstrual cycle and in lesser amounts by the corpus luteum during the second half of the menstrual cycle. Estrogens cause the development and functioning of the female reproductive system.


fingerlike projections of the epithelium of the small intestine, which increase its surface area and allow for greater absorption of nutrients.


fibrous connective tissue that attaches muscles to bone in vertebrates.


microscopic organisms that drift or swim near the surface of bodies of water, including oceans, lakes, and ponds. Two important plankton are copepods, which are tiny heterotrophic crustaceans, and phytoplankton, which include phytosynthetic algae and prokaryotic cyanobacteria. Phytoplankton account for half of global phytosynthetic activity.

Aphotic zone

the zone in the ocean that receives no light. The aphotic zone is beneath the photic zone, and since light does not penetrate the aphotic zone, no photosynthesis can occur here. Many animals in the aphotic zone subsist on detritus that rains down from the ocean layer above.


a structure in the uterus of animals that develops during pregnancy. The placenta nourishes the fetus with the blood supply from the mother and is a fusion of the uterine lining and the embryonic membranes.


the innermost layer of the eye in vertebrates; contains the photoreceptor cells (the rod and cone cells) and neurons. The retina transmits images to the brain through the optic nerve.


in plants, growth toward or away from a stimulus such as light (in phototropism), touch (thigmotropism), or gravity (gravitropism). Occurs through differential growth on the side of the plant away from the stimulus.

Rod cell

one of the two kinds of photoreceptor cells in the retina of the eye; rod cells are sensitive to black and white and enable animals to see at night.

Aposematic coloration

the bright warning coloration of animals that have effective physical or chemical defenses—aposematic coloration tells predators to avoid animals in this state.


a small blood cell that has no nucleus and is important in blood clotting; platelets are derived from larger cells in the bone marrow


the diploid result of the union of the haploid gametes (sperm and egg) in the process of fertilization. Otherwise known as the fertilized egg.


a group of interbreeding organisms (organisms of one species) that inhabit a particular geographic location.


refers to the evolutionary history of a species or a group of related species


the windpipe; reinforced by cartilaginous rings, the trachea is the part of the respiratory tube that leads from the larynx to the two bronchi.


the part of the vascular system in plants that is made up of living cells arranged into long tubes. These tubes transport sugars and other organic substances throughout the plant from the leaves (where they are produced in photosynthesis) to all other parts of the plant.


a harmless variant of the pathogen, which is intentionally introduced into the body. The vaccine stimulates the body's immune system to produce antigens against the pathogen, conferring resistance.


a fleshy underground storage structure composed of an enlarged part of the stem that has buds on its surface capable of growing into mature plants.

Turgor pressure

the force directed against the plant cell walls after water has flowed into the plant from a hypotonic environment.

Autonomic nervous system

a subdivision of the nervous system; the autonomic nervous system is involuntary and is composed of the sympathetic and parasympathetic division, which work together to regulate the internal environment.


in the life cycle of plants or algae that undergo an alternation of generations, a spore is a meitotically produced haploid cell that then divides through mitosis (and without fusing with another individual) to produce a multicellular gametophyte.


the nutrient-rich food source that is formed from the union of a sperm cell with the polar nuclei in double fertilization; this is the source of nutrients for the developing seeds in angiosperms.


the female reproductive organ of the flower; made up of the stigma, the style, and the ovary. The pistil is sometimes called the carpal.


an integrated group of cells that have a common structure and function in the body. These cells cooperate to create a specific structure or together have a specialized function in the body.


a female organ in which eggs are fertilized and the development of the embryo/fetus occurs.


A plant's physiological response to day length- the amount of sunlight that occurs during a twenty-four-hour period. Flowering is one example of a photoperiod-dependent plant activity.

Photic zone

the topmost layer of the ocean; the area of the ocean that light can penetrate sufficiently for photosynthesis to take place.


the male reproductive structure of a plant. The anther is at the end of the filament and contains the pollen sacs, where pollen grains (the male gametophytes) are produced.


a macromolecule in a host organism that is foreign to that organism and therefore instigates an immune response.


saprotrophic fungi or bacteria that absorb nutrients from nonliving organic matter, for example, dead organisms (including plants and animals) and the wastes of living organisms, and convert that to inorganic form.


an adaptation of terrestrial plants; seeds consist of the plant embryo encased along with a store of food in a tough, resistant coat.

Semicircular canal

a three-part, partially fluid-filled chamber of the inner ear that aids in maintaining equilibrium (balance) of the body.


a protein secreted by B cells (B lymphocytes; white blood cells) in the immune system; antibodies interact with antigens to generate an immune response.


a member of one of the two major branches of coelomates (the other is the deuterostomes); this branch of coelomates includes the annelids, mollusks, and arthropods. Protostomes have spiral cleavage patterns in early development and the mouth develops from the blastopore; they exhibit determinate cleavage during development.


an animal that has a solid body and lacks a cavity between the digestive tract and body wall. Some examples of acoelomates are platyhelminthes, which include the flatworms.


the synapse is the narrow cleft between the synaptic terminal of an axon and the signal-receiving part of another neuron or effector cell. Neurotransmitter molecules diffuse across the synapse from the presynaptic to the postsynaptic membrane, relaying their message.

Pituitary gland

the master gland of the endocrine system. At the base of the hypothalamus, the pituitary gland consists of an anterior section, which stores and releases two hormones produced by the hypothalamus, and a posterior section, which produces and secretes a variety of hormones


a type of flowering plant that possesses two embryonic seed leaves or cotyledons


a multicellular, diploid organism in plants that undergo alternation of generations; sporophytes are the result of the union of gametes and undergo meiosis to produce haploid spores


the tube that leads from the pharynx to the stomach. It conducts food to the stomach through peristalsis

Fallopian tube

the duct that connects the ovaries with the uterus; the passage through which the egg travels during ovulation from the ovaries to the uterus


the male reproductive organ of a flower, consisting of an anther and a filament; the stamen is the site of pollen production in the plant

Somatic nervous system

the branch of the motor division of the peripheral nervous system in vertebrates that carries signals to skeletal muscles in response to external stimuli; this system is responsible for voluntary, conscious movement. Acetylcholine is a neurotransmitter

Fixed action pattern

a series of behavioral acts that is unchangeable and usually carried to completion once initiated. FAPs are triggered by a specific stimulus

Double fertilization

in angiosperms, a method of fertilization where two sperm cells where two sperm cells unite with two cells in the embryo sac to form the zygote and the endosperm (a nutrient-rich triploid tissue that is used as the food source for the developing embryo)


the loss of water from a plant through evaporation

Root cap

a grouping of cells at the tip of the plant's roots that serve to protect the apical meristem. Root caps secrete a polysaccharide that helps break up soil and allow for enlongation of the root.


one of the two body forms of cnidarians; cnidarians with the polyp body form are sessile and have a a mouth-up body plan, such as sea anemones.

1. Hypha

The filaments that collectively make up the body of fungi. Hyphae are made up of thin threads of tubular walls that surround eukaryotelike cells.

2. Cartilage

One type of flexible connective tissue that contains collagenous fibers that are embedded in chondrin; a firm and flexible substance t hat is found in certain regions of the vertebrate skeleton.

3. Neurotransmitter

A chemical messener that is released from the synaptic terminal of a neuron and diffuse through the synaptic cleft to bind to the postsynaptic membrane. Neurotransmitters elicit excitatory or inhibitory response, which can effect myriad actions.

4. Lichen

The mutualistic symbiotic association between a fungus and photosynthetic alga.

5. Commensalism

A symbiotic relationship in which one organism (the symbiont) benefit while the other organism is neither helped nor harmed.

6. Cerebellum

Part of the hindbrain of vertebrates, the cerebellum is situated dorsally and plays a role in the unconscious coordination of movement and balance in the organism

7. Histamine

A substance released by injured cells that causes the dilation of nearby blood vessels and capillaries in an inflammatory response

8. Malpighian tubules

A excretory organ that is unique to insects, empties into the digestive tract, and removes nitrogenous wastes from the hemolymph; also plays a role in osmoregulation.

9. Cephalization

An evolutionary trend where the sensory equipment and organs of the body became centralized at the anterior end of the animal. Characteristic of animals that exhibit bilateral symmetry.

10. Pelagic zone

The oceanic zone that is past the continental shelf; this area has the greatest depth in the ocean. The pelagic zone is divided into a photic zone and an aphotic zone.

11. Parathyroid glands

Four endocrine glands that are embedded in the surface of the thyroid gland; the parathyroid glands secrete parathyroid hormoe an act to raise the blood levels of calcium.

12. Ovoviparous

Refers to animals in which the young hatch from eggs that are retained the uterus of the mother

13. Keystone species

Species that are not usually the most abundant species of a community yet have a large role in maintaining the structure of the community through their particular niches or roles. Their removal causes a significant alteration in the community.

14. Imprinting

A type of learning that occurs very early in development over a time known as a sensitive period. In this type of learning, the young animal learns to form a social bond with first individual (of any species) that it sees.

15. Mycorrizhae

The symbiotic association of a fungus and the root nodules of legumes. The fungus provides the plant with minerals that it "fixes" from the soil, and the plant provides the fungus with food in the form of sugars made in photosynthesis.

16. Notochord

A long, narrow, flexible rod of cells that urns along the dorsal axis of the body during development in chordates; the notochord lies in the future position of the vertebral column

17. Homeostasis

Internal maintenance of the steady-state physiological conditions of the body.

18. Mesophyll

The tissue of a plant leaf that is sandwiched between the upper and lower epidermis and contains cells specialized for photosynthesis (these cells contain many chloroplasts).

19. Instinct

Behavior that is innate to an organism and does not have to be learned

20. Lymphocyte

A white blood cell. Lymphocytes that develop in the bone marrow are known as B cells, where those that develop in the thymus are known as T cells


The heavy, dense, interwoven branching of hyphae in a fungus.


A type of protein filament that interacts with actin filaments to cause muscle cell contraction

Minimum viable population (MVP) size

The smallest number of individuals living in a certain habitat needed to perpetuate a population


The movement of cancerous cells to locations distant from their site of origin.


Refers to the type of development in which the young hatches from eggs that are laid outside the mother's body.

Central nervous system (CNS)

The CNS consists of the brain and the spinal cord and acts as the central command center of the body. It is made up mostly of interneurons.

Minimum dynamic area

The least amount of sustainable habitat that is needed to support a population of individuals.


The process that takes place in the ovary and produces the female gametes, the ova (singular, ovum).


A blood filtration and excretory organ characteristic of segmented worms.


A heterotroph that consumes both plants and animal materials.


A moss, liverwort, or hornwort. Any nonvascular, terrestrial plant that lacks many of the traditional terrestrial plant adaptations.

Corpus luteum

A tissue in the ovary that secretes estrogens and progesterone; the follicle becomes the corpus luteum after ovulation (release of the egg).

Interstitial fluid

In vertebrates, the substance that fills the space in between cells and is the site of the exchange of nutrients for waste by capillary exchange.


The structure that develops in the ovary of the plant and contains the female gametophyte and gametes; after fertilization, the ovule develops into the seed.


In animal development, a hollow ball of cells, the formation of which marks the end of cleavage, very early in development.


A cell of the immune system that is amoeboid in structure. Macrophages travel through tissue fibers, phagocytotically engulfing bacteria and dead cells.


All of the organisms that live in a particular geographic area; a community is a group of populations of different species that live close together and interact with one another.


An animal with a fluid-filled body cavity that is completely lined by mesodermal tissue. The layers of this mesoderm tissue connect both dorsally and ventrally and form mesenteries.


A white blood cell; this type of cell has an important role in the immune system and can phagocytosize foreign agents and particles in the body. Leukocytes are also involved in the production of antibodies.

Negative feedback

A mechanism of hormone functionality in the body in which a change in physiological variable that is monitored by the body triggers a response counteracting that change.


The group of flowering plants (angiosperms) whose members possess one embryonic seed leaf (cotyledon) during embryonic development. Monocots are usually characterized by a fibrous root system, flower parts that occur in threes,


A mixture of substances produced by the liver. Bile is stored in the gallbladder and acts as a detergent, contributing to the digestion and absorption of fats through emulsification.


The classification of organismstree; according to the order in time at which they branched off a phylogenetic tree; this system does not take into consideration the amount of morohloical divergence.

Carrying capacity

the maximum population size that a certain environment, with limited resources and geographic space, can support. Carrying capacity is symbolized as K.

Classical conditioning

Associative learning (learning to associate one stimulus with another) in which an animal learns to associate an arbitrary stimulus with a specific reward or punishment.


the indentation, or opening, of the archenteron in the gastrula stage of animal development; in protostomes this eventually develops into the mouthl in deuterostomes it develops into the anus.


the area of a plant stem where one or more leaves are attached. The parts of the stem between nodes are called internodes.

Cone cell

one of the two types of photoreceptors in the retina of the eye; cone cells allow humans to see color during the day.

Interdinal zone

the shallow zone of the ocean where the ater meets the shore; this zone periodically changes with the changing tides. Also called the littoral zone.


the sum of a species' use of the biotic and abiotic resources in its particular environment. No two species can have the same niche in the same environment.

Neritic zone

the shallow zone of the ocean that is above the continental shelves; it extends to about 600 feet beneath the surface and is hoe to many algae, crustaceans, and fish.


a flowering plant; angiosperms have a vascular system and form seeds inside protective compartments known as ovaries.


a cancer-causing gene. A particular type of noncancerous gene, called a proto-oncogene, can be converted to an oncogene through mutation.

Mullerian mimicry

two or more species that have bright warning coloration and are both either unpalatable or have another type of chemical defense capability.


a protein found in red blood cells that has an iron-containing heme group capable of reversibly binding oxygen. This molecule is responsible for transporting oxygen around the body.


the sum of the dry weights of all of the organic matter constituting a group of organisms in a particular habitat. The biomass of a particular species is the sum of the dry weights of all of the species that inhabit the particular habitat. Biomass decreases going up a food chain.


the section of the brain in the ventral part of the forebrain. It is in charge of maintaining homeostasis by coordinating the nervous and endocrine systems. It also secretes hormones targeted to the anterior and posterior pituitary.


an organism that is unable to photosynthesize and must obtain organic molecules by consuming photosynthetic organisms, or autotrophs. All consumers and decomposers are heterotrops, whereas primary producers are autotrophs.

Medulla oblongata

the lowest part of the vertebrate brin, dorsal to the anterior spinal cord, this section of the brain controls the autonomic, homeostatic functions of te body, including breathing, heart and blood vessel changes, swallowing, and digestion.

Define: Telomere

The end of a eukaryotic chromosome; consists of tandemly repeated DNA sequences and protects the end of the chromosomes from being degraded through multiple rounds of replication.

Define: Leading strand

The continuously synthesized strand of DNA in DNA replication, synthesized in the 5' to 3' direction by DNA polymerase. This strand elongates in a direction toward the replication fork.

Define: Lagging strand

The discontinuously synthesized strand of DNA that elongates in a direction away from the replication form through the formation of series of Okazaki fragments. DNA polymerase can only add nucleotides to the 3' end of growing DNA strand.

Define: Promoter

A specific sequence of nucleotides in DNA that binds to RNA polymerase and indicates the starting point of mRNA transcription.

The set of observable and unobservable traits of an organism is known as what?

The phenotype of an organism is the set of all of the physical and physiological traits of an organism.

What type of speciation occurs when populations have geographically separate ranges?

Allopatric speciation. This causes and interrupted of gene flow between members of the two distinct populations and results in the evolution of new species.

Define: Histone

A protein molecule that has a slightly positive charge and binds to the negatively charged DNA molecule; together histones and DNA form chromatin.

Define: Intron

The noncoding regions and sequences of a eukaryotic genome, interrupted by coding regions known as exons.

Define: Sex chromosome

A chromosome involved in determining the sex of an individual. Humans have two sex chromosomes and forty-four autosomes. Human females have two X chromosomes, whereas males have one X chromosome and one Y.

Define: Inclusive fitness

An individual's fitness, including both the genes that the individual passes on to the next generation and the shared genes that the individual helps to pass along through altruism, for example.

Define: Incomplete dominance

In this type of inheritance, the F1hybrids have an appearance that is intermediate between the phenotypes (appearance) of the two parents.

Define: Transfer RNA (tRNA)

An RNA molecule that acts as an interpreter between mRNA and proteins by picking up specific amino acids and pairing them with compatible codons on mRNA during translation.


the innermost layer of the eye in vertebrates; contains the photoreceptor cells (the rod and cone cells) and neurons. The retina transmits images to the brain through the optic nerve.


in plants, growth toward or away from a stimulus such as light (in phototropism), touch (thigmotropism), or gravity (gravitropism). Occurs through differential growth on the side of the plant away from the stimulus.

Rod cell

one of the two kinds of photoreceptor cells in the retina of the eye; rod cells are sensitive to black and white and enable animals to see at night.

Aposematic coloration

the bright warning coloration of animals that have effective physical or chemical defenses—aposematic coloration tells predators to avoid animals in this state.

Origin of replication

Site where the replication of the DNA molecule begins in DNA synthesis. Also the site where DNA polymerase and the other protein associated with DNA synthesis initially bind.


A haploid sex cell (an egg or a sperm cell); male and female gametes join during fertilization to produce a diploid zygote. Gametes are produced by germ cells.


the phenotype of an organism is codominant when two alleles affect the phenotype in separate, distinguishable ways; both alleles are expressed in the phenotype.


A complex that consists of a very long DNA molecule and associated proteins known as histones. Chromosomes are threadlike and carry the genes of an organism.

Amino acid

a monomer of a protein: a central carbon attached to an amino group (-NH2), a carboxyl group (-COOH), and a hydrogen atom that is variable and determines the amino acid's chemical properties.


A theory of evolution on Earth stating that all evolutionary change has been the result of the accumulation of small but continuous changes and processes. This theory was replaced by the theory of punctuated equilibrium.


In a nondividing cell, a mass of long, thin fibers that aren't visible with a light microscope' however, before cell division, the chromatin condenses into chromosomes and becomes visible.


One of two coelomate divisions (the other is the protostomes) characterized by a radial cleavage pattern during early development, indeterminate cleavage, and the development of the blastopore into the anus. This group includes the echinoderms and the chordates.

Natural selection

Darwin's theory that differential success in the reproduction of organisms with different phenotypes results from the interaction of these individuals with their environments. Evolution occurs because those better suited to an environment will survive to produce more offspring and pass along their genes to the next generation.

What term describes the lining up of homologous chromosomes during prophase I of meiosis?

The lining up and pairing of homologous chromosomes during prophase I of meiosis is known as synapsis.


Refers to members of a family of closely related plant organelles, including chloroplasts, chromoplasts, and amyloplasts(leucoplasts).

Polymerase chain reaction

A lab technique for quickly making multiple copies of a DNA segment in vitro by incubating the fragment with a primer, nucleotides, and DNA polymerase


Pyruvate is the end product of glycolysis - a three-carbon compound. Pyruvate is converted to acetyl coA before entering the Krebs Cycle.

Allosteric site

A specific site on the enzyme where an allostatic inhibitor or actovator binds quickly; the binding causes a conformational change in the enzyme that either inhibits the enzyme or stimulates it to catalyze a reaction. This site is separate from the activate site.


A form of endocytosis by which the cell takes in macromolecules


An agent ( either chemical or physical) that causes an alteration in the DNA sequence.

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