Chapter 3
Chromosomes consist of ________ and ________.
DNA and proteins
Phases of interphase
G1, S, G2
The enzyme ________ is required for the synthesis of mRNA.
RNA polymerase
Identify the role of cholesterol in the plasma membrane.
affects membrane permeability
During mitosis, chromatids separate into daughter chromosomes in
anaphase
The genetically programmed death of cells is called
apoptosis
As a red blood cell matures, it loses all of its DNA. As a result, it __________.
cannot make new RNA
When activated, lysosomes function in
digestion of materials
The intake of materials from the extracellular fluid using vesicles is called
endocytosis
Which of the following is not required for osmosis to occur?
energy
A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.
exocytosis
Passive movement of a solute by a carrier protein is called __________.
facilitated diffusion
Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.
facilitated diffusion
If an animal cell lacked centrioles, it would not be able to
form the mitonic spindle
Renewal or modification of the cell membrane is a function of the
golgi apparatus
A solution that contains a lower osmotic pressure than the cytoplasm of a cell is called
hypotonic
A gene is a set of specific instructions that
indicates the sequence of amino acids in a protein molecule.
The stage in a cell's life cycle in which the cell performs its normal functions is called __________.
interphase
When is DNA replicated?
interphase
During which phase of the cell cycle does DNA duplication, or replication, take place?
interphase (new daughter cell formed)
Receptor molecules on the surface of cells bind specific molecules called, in general,
ligands
The endoplasmic reticulum is an example of a(n) ________ organelle.
memberous
__________ function(s) as the template during translation.
messanger RNA
During which phase of mitosis do sister chromatids line up at the center of the cell?
metaphase
Each of the following is a function of smooth endoplasmic reticulum except
modification of protein
A primary active transport process is one in which __________.
molecules move through transport proteins that have been activated by ATP
what best describes diffusion
movement of molecules from an area of high concentration to an area of low concentration
One of the characteristics of cancer cells is an increased need for protein production. Of the following choices, which organelle would be most closely associated with meeting this need?
necleoli
What is the normal direction of calcium transport via the calcium pump?
out of the cell, against its concentration gradient
Organelles that break down fatty acids and hydrogen peroxide are
peroxosomes
Whenever positive and negative ions have been separated, a(n) ________ will be produced.
potential difference
Mitosis phases order
prohase, metaphase, anaphase, telophase
During which phase of mitosis do the nuclear envelope and nucleoli disappear?
prophase
Tubulin is a
protein that assembles into microtubules.
Facilitated diffusion differs from simple diffusion in that facilitated diffusion __________.
requires a protein carrier
Water crosses the plasma membrane primarily by means of __________.
simple diffusion
Synthesis of lipids and glycogen takes place at the
smooth ER
_______ cells are all of the cells of the body except the reproductive cells (sperm and oocytes).
somatic
As each codon arrives at the active site of a ribosome, it attracts another molecule containing the anticodon. This molecule is called
tRNA
The chromosomal structure that limits the number of cell divisions of a cell is the __________.
telomere
During which phase of mitosis do nuclear envelopes and the nucleoli reappear?
telophase
The smallest living unit within the human body is
the cell
The potential difference across the cell membrane is known as
the membrane potential
The process of protein formation directed by mRNA is called
translation
