AP Biology Unit 4 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Endocrine system - CORRECT ANSWER - Secretes hormones into blood from ductless
glands that coordinate slower but longer-acting responses
Paracrine - CORRECT ANSWER - Signals act on cells near the secreting cell
Local regulators - CORRECT ANSWER - Chemical signals that travel over short distances
due to diffusion
Autocrine - CORRECT ANSWER - Signals act on the secreting cell itself (usually for
apoptosis)
Type I diabetes - CORRECT ANSWER - An autoimmune disorder in which the immune
system destroys pancreatic beta cells (usually develops while you're young)
Type II diabetes - CORRECT ANSWER - Involves insulin deficiency or reduced response of
target cells due to change in insulin receptors (due to being overweight and not exercising)
Signal Transduction - CORRECT ANSWER - The linkage of mechanical, chemical, or
electromagnetic stimulus to a specific cellular response
Hormone - CORRECT ANSWER - A regulatory substance produced in an organism and
transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.
Negative Feedback - CORRECT ANSWER - The diminution or counteraction of an effect by
its own influence on the process giving rise to it, as when a high level of a particular hormone in
the blood may inhibit further secretion of that hormone, or where the result of a certain action
may inhibit further performance of that action.
, anaphase - CORRECT ANSWER - fourth stage of mitosis, in which the chromatids of each
chromosome have separated and the daughter chromosomes are moving to the poles of the cell
benign tumor - CORRECT ANSWER - a mass of abnormal cells that remains at the site of
origin
cell cycle - CORRECT ANSWER - an ordered sequence of events in the life of a eukaryotic
cell, from its origin in the division of a parent cell until its own division into two; composed of
M, G1, S, G2
centrioloes - CORRECT ANSWER - important during cell division; origin spindle fibers
centromere - CORRECT ANSWER - the centralized region joining two chromatids
checkpoint - CORRECT ANSWER - a critical control point in the cell cycle where stop and
go-ahead signals regulate the cycle
chromatin - CORRECT ANSWER - complex of DNA and proteins that makes up a eukaryotic
chromosome; when a cell is not diving it exists as a mass of very long, thin fibers that are not
visible with a light microscope
chromosome - CORRECT ANSWER - a threadlike, gene-carrying structure found in the
nucleus; each consists of one very long DNA molecule and associated proteins
cleavage - CORRECT ANSWER - the process of cytokinesis in animal cells, characterized by
pinching of the plasma membrane. Also, the succession of rapid cell divisions without growth
during early embryonic development that converts the zygote into ball of cells
cleavage furrow - CORRECT ANSWER - the first sign of cleavage in an animal cell;a
shallow groove in the cell surface near the old metaphase plate
Exam Questions and CORRECT Answers
Endocrine system - CORRECT ANSWER - Secretes hormones into blood from ductless
glands that coordinate slower but longer-acting responses
Paracrine - CORRECT ANSWER - Signals act on cells near the secreting cell
Local regulators - CORRECT ANSWER - Chemical signals that travel over short distances
due to diffusion
Autocrine - CORRECT ANSWER - Signals act on the secreting cell itself (usually for
apoptosis)
Type I diabetes - CORRECT ANSWER - An autoimmune disorder in which the immune
system destroys pancreatic beta cells (usually develops while you're young)
Type II diabetes - CORRECT ANSWER - Involves insulin deficiency or reduced response of
target cells due to change in insulin receptors (due to being overweight and not exercising)
Signal Transduction - CORRECT ANSWER - The linkage of mechanical, chemical, or
electromagnetic stimulus to a specific cellular response
Hormone - CORRECT ANSWER - A regulatory substance produced in an organism and
transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.
Negative Feedback - CORRECT ANSWER - The diminution or counteraction of an effect by
its own influence on the process giving rise to it, as when a high level of a particular hormone in
the blood may inhibit further secretion of that hormone, or where the result of a certain action
may inhibit further performance of that action.
, anaphase - CORRECT ANSWER - fourth stage of mitosis, in which the chromatids of each
chromosome have separated and the daughter chromosomes are moving to the poles of the cell
benign tumor - CORRECT ANSWER - a mass of abnormal cells that remains at the site of
origin
cell cycle - CORRECT ANSWER - an ordered sequence of events in the life of a eukaryotic
cell, from its origin in the division of a parent cell until its own division into two; composed of
M, G1, S, G2
centrioloes - CORRECT ANSWER - important during cell division; origin spindle fibers
centromere - CORRECT ANSWER - the centralized region joining two chromatids
checkpoint - CORRECT ANSWER - a critical control point in the cell cycle where stop and
go-ahead signals regulate the cycle
chromatin - CORRECT ANSWER - complex of DNA and proteins that makes up a eukaryotic
chromosome; when a cell is not diving it exists as a mass of very long, thin fibers that are not
visible with a light microscope
chromosome - CORRECT ANSWER - a threadlike, gene-carrying structure found in the
nucleus; each consists of one very long DNA molecule and associated proteins
cleavage - CORRECT ANSWER - the process of cytokinesis in animal cells, characterized by
pinching of the plasma membrane. Also, the succession of rapid cell divisions without growth
during early embryonic development that converts the zygote into ball of cells
cleavage furrow - CORRECT ANSWER - the first sign of cleavage in an animal cell;a
shallow groove in the cell surface near the old metaphase plate
