ap biology

Ligands

A molecule that binds specifically to a receptor site of another molecule.

Local Regulators

A secreted molecule that influences cells near where it is secreted.

Biotic

Describes living factors in the environment.

Abiotic

Non-living things

keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

analogous structures

Body parts that share a common function, but not structure

vestigial structures

A structure that is present in an organism but no longer serves its original purpose

homologous structures

Structures in different species that are similar because of common ancestry.

Positive Feedback

A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.

Negative Feedback

A type of regulation that responds to a change in conditions by initiating responses that will counteract the change. Maintains a steady state.

Stimulus

any event or situation that evokes a response

Stimuli

Changes in the environment

Neurotransmitters

Chemicals that transmit information from one neuron to another

neurosecretory cells

Neurons of the hypothalamus that secrete neurohormone rather than neurotransmitter

Centromere

the region of the chromosome that holds the two sister chromatids together during mitosis

IPMAT-C

Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

G1 phase

stage of interphase in which cell grows and performs its normal functions

G1 checkpoint

checks to see if cell size is adequate; chromosomes replication is successfully completed and checks for DNA errors

G0 phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

G2 phase

The Second stage of interphase in which cell duplicates its cytosol and organelles

G2 checkpoint

The cell checks to make sure the DNA is copied correctly

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Prophase (mitosis)

chromosomes condense and spindle apparatus begins to form

Metaphase (mitosis)

Chromosomes line up in the middle of the cell

Anaphase (Mitosis)

cell elongates and sister chromatids are pulled apart toward the poles

Telophase (mitosis)

chromosomes begin to uncoil, spindles break down, and new nuclear membrane forms.

Cytokinesis in animal cells

The cell membrane is drawn inward until the cytoplasm is pinched into two nearly equal parts

cytokinesis in plant cells

divide from inside out using a cell plate in middle of cell

Growth factor

A protein secreted by certain body cells that stimulates other cells to divide

density-dependent inhibition

The arrest of cell division occurs when cells touch one another.

anchorage dependent

The requirement that a cell must be attached to a solid surface in order to initiate cell division.

Mutations

changes in the genetic material

Deletion

A change to a chromosome in which a fragment of the chromosome is removed.

Duplication

When a fragment from one chromosome joins to a sister chromatid or homologous chromosome

Inversion

When a fragment reattaches to the original chromosome but in the reverse direction

Translocation

The attachment of a chromosomal fragment to a nonhomologous chromosome

Translation

Process by which mRNA is decoded and a protein is produced

Transcription

synthesis of an RNA molecule from a DNA template

DNA polymerase

Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

RNA polymerase

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

p35

tumor suppressor protein that is an IDP, gets highly mutated in cancer patients, transcription factor serves as an interactive hub

Protein Kinase

An enzyme that activates another molecule by phosphorylating it.

Protein Kinase Signal Cascade

A type of intracellular signaling where a series of protein Kinase add a phosphate group to the next protein in the cascade

Oncogenes

cancer causing genes

Proto-oncogenes

normal cellular genes that are important regulators of normal cellular processes, they promote growth. alterations in the expression of these cells result in oncogenes

Carcinogen

A cancer-causing substance

Mutagen

A chemical or physical agent that interacts with DNA and causes a mutation.

Pathogen

a bacterium, virus, or other microorganism that can cause disease.

immune system

A system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response

innate immunity

Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

inflammatory response

An innate body defense in vertebrates caused by a release of histamine and other chemical alarms signal that triggers an increase in blood flow, a local increase in white blood cells, and fluid leakage from the blood

• Results in Redness, heat, and swelling

Adaptive immunity

A vertebrate-specific defense that is activated only after exposure to an antigen and is mediated by lymphocytes

lymph nodes

an organ that filters lymph and that is found along the lymphatic vessels

Passive Immunity

Temporary immunity obtained by acquiring ready-made antibodies

Active Immunity

Immunity conferred by recovering from an infectious disease or by receiving a vaccine.

Antigen

A foreign molecule that evoke an adaptive immune response

Antibody

A protein dissolved in blood plasma that attaches to a specific kind of antigen that helps counter the effects of the antigen

humoral immune response

The type of specific immunity brought about by antibody-producing B-cells

cell-mediated immune response

The type of specific immunity brought about by T-cells; fights body cells infected with pathogens

Clonal selection

The production of a lineage of genetically identical cells that recognize and attack the specific antigen that stimulate their proliferation

Memory Cells

A clone of long-lived lymphocytes formed during the primary immune response; remains in a lymph node until activated by exposure to the same antigen that triggered its formation: when activated, a memory cell forms a large clone that mounts the secondary immune response

Primary immune response

the initial immune response to an antigen, which appears after a lag of several days

Secondary immune response

Immune response after the body has already been exposed to a specific antigen. Response is faster, of greater magnitude, and more prolonged.

Monoclonal Antibodies (mAb)

An antibody secreted by a clone of cells and therefore specific for the one antigen that triggered the development of the clone

B cells

Cells manufactured in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses.

Macrophages

Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.

Helper T-cells

T cells that help the immune system by increasing the activity of killer cells, stimulating the suppressor T cells, and may help stimulate B-cells to produce antibodies

Cytoxic T-cells

A type of lymphocyte that attacks body cells infecteed with pathogens

Killer T-cells

Lymphocytes that use enzymes to destroy the cell membranes of bacteria and other foreign invaders.

Antigen-presenting cells (APCs)

One of a family of white blood cells that ingests a foreign substance or a microbe and attaches antigenic portions of the ingested material to its surface, thereby displaying the antigens to a helper T-cell

Insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues

Glucagon

A hormone secreted by the pancreatic alpha cells that increases blood glucose concentration

Type I Diabetes

Insulin Dependent; Results when the pancreas does not produce insulin

Type II Diabetes

Non-Insulin Dependent; Results when body cells fail to respond to insulin

Hypoglycemia

An Abnormally low level of glucose in the blood that results when the pancreas secrets too much insulin into the blood

Microevolution

Change in allele frequencies in a population over generations.

Macroevolution

Evolutionary change above the species level.

Speciation

Formation of new species

homologous structures

Structures in different species that are similar because of common ancestry.

analogous structures

Body parts that share a common function, but not structure

Directional Selection

Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals.