In the plasma membrane, _________ form(s) the lipid bilayer, __________ determine(s) the fluid membrane, and ___________ mainly determine(s) the function of the membrane.
phospholipids, cholesterol, proteins
Which of the following functioning proteins are found in the plasma membrane?
-channel proteins
-marker proteins
-receptor proteins
-enzymes
In general, lipid-soluble molecules diffuse through the _________; small, water-soluble molecules diffuse through the ____________.
lipid bilayer, carrier proteins
Small pieces of matter, and even whole cells, can be transported across the membrane in?
vesicles
The rate of diffusion increases if the...
viscosity of a solution decreases
Concerning the process of diffusion, at equilibrium...
-the net movement of solution stops
-random molecular motion continues
-there is an equal movement of solute in the opposite directions
-the concentration of solute is equal throughout the solution
If a cell is placed in a(n) __________ solution, lysis of the cell may occur.
hypotonic
Suppose that a woman runs a long-distance race in the summer. During the race, she loses a large amount of hyposmotic sweat. You would expect her cells to...
shrink
Which of these statements about facilitated diffusion is true?
In a facilitated diffusion, net movement is down the concentration gradient.
Which of these statements concerning the symport of glucose into cells is true?
The concentration of glucose can be greater inside cells then outside cells.
A white blood cell ingests solid particles by forming vesicles. This describes the process of...
phagocytosis
Given these characteristics:
requires energy
requires carrier proteins
requires membrane channels
requires vesicles
Choose the characteristics that apply to exocytosis.
!. Requires energy
4. Requires vesicles
Cytoplasm is found
outside the nucleus and inside the plasma membrane
Which of these elements of the cytoskeleton is composed of tubulin and forms essential components of centrioles, spindle fibers, cilia, and flagella?
A) actin filaments
B) intermediate filaments
C) microtubules
c. microtubules
A large structure, normally visible in the nucleus of a cell, where ribosomal subunits are produced is the
A) endoplasmic reticulum.
B) mitochondria.
C) nucleolus.
D) lysosome.
c. nucleolus
A cell that synthesizes large amounts of protein for use outside the cell has a large
A)number of cytoplasmic inclusions.
B)number of nuclei. C)amount of rough endoplasmic reticulum.
D)amount of smooth endoplasmic reticulum.
E)number of lysosomes.
c. amount of rough endoplasmic reticulum
Which of these organelles produces large amounts of ATP?
A) nucleus
B) mitochondria
C) ribosomes
D) endoplasmic reticulum
E) lysosomes
b. mitochondria
Cylindrically shaped extensions of the plasma membrane that do not move, and are supported with actin filaments; they may function in absorption or as sensory receptors. This describes
A) centrioles.
B) spindle fibers.
C) cilia.
D) flagella.
E) microvilli.
e. microvilli
A portion of an mRNA molecule that determines one amino acid in a polypeptide chain is called a
A) nucleotide.
B) gene.
C) codon.
D) exon.
E) intron.
c. codon
In which of these organelles is mRNA synthesized?
A) nucleus
B) ribosome
C) endoplasmic reticulum
D) nuclear envelope
E) peroxisome
a. nucleus
During the cell life cycle, DNA replication occurs during the
A) G1 phase.
B) G2 phase.
C) M phase.
D) S phase.
d. S phase
Given the following activities:
1. repair
2. growth
3. gamete production
4. differentation
Which of these following activities is (are) the result of mitosis?
1. repair
2. growth