Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

The overall structure of the plasma membrane is a mosaic with the components locked tightly in place.

What is the primary difference between active transport processes and passive transport processes?

Match the term with its appropriate definition. 

Osmosis    

Secondary active transport    

Exocytosis    

Phagocytosis    

Simple diffusion    

Primary active transport    

Pinocytosis    

Facilitated diffusion

a. Type of endocytosis in which a large particle is ingested

b. Transport across the plasma membrane against the concentration gradient via direct use of energy from ATP

c. Passive movement of solute across the plasma membrane

d. Movement of solvent from a solution of lower solute concentration to a solution of higher solute concentration

e. Passive movement of solute across the plasma membrane via a channel or carrier protein

f. Type of endocytosis in which ECF is brought into the cell in a protein-coated pit

g. Release of large substances from the cell through a vesicle

h. Transport of a substance across the plasma membrane against its concentration gradient using the energy from the 'downhill' movement of another substance

A hypotonic solution will cause water to move ________the cell, and the cell will ______.

A hypertonic solution will cause water to move ______the cell, and the cell will ________.

Match the following terms with the correct functions.

Peroxisome     

Ribosome     

Smooth endoplasmic reticulum     

Mitochondrion     

Golgi apparatus     

Lysosome     

Rough endoplasmic reticulum     

Vesicle

a. Modifies and folds proteins into the correct structure

b. Modifies, packages, and sorts proteins

c. Contains digestive enzymes

d. Granular organelle that makes proteins

e. Synthesizes most of a cell’s ATP

f. Contains enzymes that oxidize toxins and fatty acids

g. Membrane-enclosed structure used to transport substances through the cell

h. Detoxifies certain chemicals, makes lipids, stores calcium ions

Explain how the members of the endomembrane system interact.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

Actin filaments combine with myosin motor proteins to provide the cell with mechanical strength.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

The cilia found on sperm cells propel the cells through a liquid medium.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

Microtubules are hollow tubes that align organelles and shuttle them to their proper places in the cell.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

Intermediate filaments are ropelike structures composed of tubulin proteins.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

Centrioles are part of the centrosome from which microtubules originate.

Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.

Endocytosis, exocytosis, muscle cell contraction, and cellular 'crawling' are all mediated by intermediate filaments.

Our somatic cells' DNA is distributed among 46 ________ in the nucleus.

a. Nucleosomes

b. Chromatids

c. Nucleoli

d. Chromosomes

Explain how and why chromatin is condensed in the nucleus.

Which of the following statements correctly describes the function of the nucleolus?

a. Within the nucleolus we find genes for rRNA.

b. Nucleoli manufacture mitochondrial proteins for export to the cytosol.

c. Nucleoli assemble the nuclear envelope.

d. The nucleolus contains the genes that form the Golgi apparatus.

Each of the following statements about protein synthesis is false. Correct each to make a true statement.

In a gene, each nucleotide specifies one amino acid in a protein sequence.

Each of the following statements about protein synthesis is false. Correct each to make a true statement.

A transcription factor must bind to the promoter region of a gene before the enzyme DNA synthetase is able to bind and begin transcription.

Each of the following statements about protein synthesis is false. Correct each to make a true statement.

The enzyme RNA polymerase builds a strand of transfer RNA, whose codons are complementary to DNA's triplets.

Each of the following statements about protein synthesis is false. Correct each to make a true statement.

Proteins destined for secretion from the cell enter the nucleus after translation, to be folded and modified.

Each of the following statements about protein synthesis is false. Correct each to make a true statement.

During translation, amino acids are delivered by the messenger RNA transcript.

Number the following steps of protein synthesis in the order in which they occur, starting with 1 and ending with 9.

a. _____The stop codon is reached, and the polypeptide is released. 

b. _____The small ribosomal subunit finds the start codon, and the large ribosomal subunit joins. 

c. _____The end of the gene is reached, and the pre-mRNA is released and then edited. 

d. _____The transcription factor binds the promoter. 

e. _____The protein is folded and modified to become functional. 

f. _____ RNA polymerase builds the mRNA transcript. 

g. _____mRNA and initiator tRNA bind the small ribosomal subunit. 

h. _____ New tRNAs are brought into the A site successively, and the peptide chain of the tRNA in the P site is joined to the amino acid of the tRNA in the A site.

i. ______mRNA exits the nucleus via a nuclear pore.

Which of the following is not a phase of mitosis?

a. Interphase

b. Prophase

c. Anaphase

d. Metaphase

Why is regulation of the cell cycle necessary?

Mark the following statements about the cell cycle as true or false. If a statement is false, correct it to make a true statement.

During the S phase of the cell cycle, the cell stalls until conditions for division are more favorable

Mark the following statements about the cell cycle as true or false. If a statement is false, correct it to make a true statement.

During metaphase, the sister chromatids are pulled apart and the chromosomes move to the opposite poles of the cell.

Mark the following statements about the cell cycle as true or false. If a statement is false, correct it to make a true statement.

The main enzyme that builds the new DNA strands during DNA synthesis is RNA synthetase.

Mark the following statements about the cell cycle as true or false. If a statement is false, correct it to make a true statement.

The first three stages of the cell cycle are collectively called interphase.

Match the following terms with the correct definitions. 

G1     

Metaphase     

S phase     

Cytokinesis 

Telophase

M phase

G2 

Anaphase

a. Division of the cytoplasm

b. Second growth stage of the cell cycle

c. Stage of the cell cycle in which the cell divides

d. Stage of mitosis in which the sister chromatids line up on the cell's equator

e. Stage of the cell cycle in which DNA is replicated

f. Stage of mitosis in which the chromosomes move to opposite poles of the cell

g. Initial growth phase of the cell cycle

h. Stage of mitosis in which the nuclear envelopes reassemble