Biology

A plant cell is placed in a hypotonic solution. As a result, the cell will

(A) lyse
(B) swell but remain intact
(C) shrivel
(D) remain unchanged
(E) take up solutes
Biology

A cell normally contains 54 chromosomes. During which phases of mitosis does the cell contain 108 chromosomes?

(I.) Anaphase
(II.) Metaphase
(III.) Prophase
(IV.) Telophase

 

(A) I and IV
(B) II and III
(C) II and IV
(D) I, II, and III
(E) I, II, and IV
Biology

Organisms that comprise the greatest mass of living substance (biomass) in a terrestrial food chain

(A) Decomposers (e.g., bacteria)
(B) Producers (e.g., grasses)
(C) Primary consumers (e.g., mice)
(D) Secondary consumers (e.g., snakes)
(E) Tertiary consumers (e.g., hawks)
Biology

A solute cannot move into a cell by crossing the phospholipid bilayer of the membrane. It can, however, enter through a membrane protein. The fact that solute molecules are entering the cell MOST LIKELY indicates that

(A) energy is being expended by the cell
(B) the solute is moving against its concentration gradient
(C) the solute molecules are hydrophilic
(D) the cell is in a hypotonic solution
(E) solute concentration is higher inside than outside the cell
Biology

Which of these cell structures contains one or more membranes?

(I.) Ribosome
(II.) Plasma membrane
(III.) Endoplasmic curriculum
(IV.) Golgi body

 

(A) II only
(B) IV only
(C) I and II
(D) I, II, and III
(E) II, III, and IV
Biology

In a breeding experiment using gray and white mice of unknown
genotypes, the following results were obtained.

If two gray progeny of cross IV mate with each other, what is the probability that any one individual offspring will be gray?

(A) 100%
(B) 75%
(C) 50%
(D) 25%
(E) 0
Biology

Which of these BEST describes the part of the molecule shown?

(A) It is hydrophilic.
(B) It forms the outer layer of the plasma membrane.
(C) It is composed of phosphate atoms.
(D) It contains nonpolar covalent bonds.
(E) It is capable of hydrogen bonding.
Biology

The genetic code table shows the amino acids that correspond to mRNA codons. Each codon is read from 3′ (first nucleotide) to 5′ (third nucleotide). A DNA template strand is shown.

Which amino acid sequence will be assembled from the mRNA associated with this strand?

DNA template strand: 5′-GCG ACA TAC ACT-3′

(A) Ala-Cys-Met
(B) Arg-Cys-Met
(C) Ala-Thr-Tyr-Thr
(D) Ala-Thr-Tyr-Trp
(E) Arg-Thr-Tyr-Thr
Biology

An original cell replicates its DNA. The cell undergoes mitosis and cell division, and one of the daughter cells replicates its DNA. Which of these BEST describes the DNA of the second-generation daughter cells?

(A) One of the cells will contain DNA consisting of one strand from the original cell.
(B) One of the cells will contain DNA consisting of two strands from the original cell.
(C) Both of the cells will contain DNA consisting of one strand from the original cell.
(D) Both of the cells will contain DNA consisting of two strands from the original cell.
(E) Neither of the cells will contain DNA consisting of strands from the original cell.