Practice test

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?

A + G= C + T

The rungs of the twisted ladder are composed of

A to T, G to C

Eukaryotic sexual life cycles show tremendous variation. Which of the following characteristics do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores A) II, III, and IV B) I, II, III, IV, and V C) I, II, and IV D) II, IV, and V

A) II, III, and IV

Which of the following statements correctly describes a karyotype? A) It is an organized image of a cell's chromosomes. B) It reveals the appearance of an organism. C) It is a display of a cell's mitotic stages. D) It is a display of all of the cell types in an organism.

A) It is an organized image of a cell's chromosomes.

During which of the following phases of meiosis do homologous chromosomes separate? A) prophase I B) anaphase II C) mitosis D) anaphase I

Anaphase I

A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon based life form that has DNA. You grow the cells in N15 medium for several generations and then transfer them to 14N medium. Which pattern in the figure above would you expect if the DNA was replicated in a conservative manner

B

Which of the following is not true of RNA processing? A) RNA splicing can be catalyzed by spliceosomes. B) Exons are cut out before mRNA leaves the nucleus. C) Nucleotides may be added at both ends of the RNA. D) Ribozymes may function in RNA splicing.

B) Exons are cut out before mRNA leaves the nucleus.

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal? A) Crossing over of chromosomes takes place in meiosis II. B) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells. C) Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. D) Homologous chromosomes align on the metaphase plate in meiosis II.

B) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

Which of the following processes occur during meiosis but not mitosis? A) Haploid cells multiply into more haploid cells. B) Haploid cells fuse to form diploid cells. C) Diploid cells form haploid cells. D) A diploid cell combines with a haploid cell.

C) Diploid cells form haploid cells.

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. A bar graph shows DNA content (n) from 0 to 8. Three samples have the following amounts of DNA: Sample I, 2 units; sample II, 4 units, sample III, 1 unit. Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior to meiosis?

C) II

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents? A) It has one-fourth the DNA and one-half the chromosomes as the parent cell. B) It has half the chromosomes but twice the DNA of the parent cell. C) It has half the amount of DNA as the cell that began meiosis. D) It is genetically identical to another cell formed from the same meiosis I event.

C) It has half the amount of DNA as the cell that began meiosis.

An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. What type of mutation does this change represent? A) a silent mutation B) a missense mutation C) frameshift mutation D) a point mutation

C) frameshift mutation

Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase? A) aminoacyl-tRNA synthetase B) anticodons C) several transcription factors D) ribosomes and tRNA

C) several transcription factors

Meiosis II is similar to mitosis in that A) the daughter cells are diploid. B) DNA replicates before the division. C) sister chromatids separate during anaphase. D) homologous chromosomes synapse.

C) sister chromatids separate during anaphase.

In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen and (N15) and then transferred them to a medium containing N14. Which of the results in the figure above would be expected after one round of DNA replication in the presence of N14

D

Okazaki fragments are formed because

DNA polymerase can only work from the 3' to the 5' end

Which of the following is NOT a difference between DNA and RNA

Found in eukaryotes and not prokaryotes

In his transformation experiments, what did Griffth observe

Mixing a heat- killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form

It was recognized that nucleic acids were the hereditary material. Garrod deduced that they expressed themselves by producing enzymes by

Noting that people with a hereditary disorder lacked one particular enzyme

Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be able to grow on medium supplemented with which of the following nutrient(s)? A) nutrient A only B) nutrient B only C) nutrient C only D) nutrients A and C

Nutrient C only

In 1944 Avery, MacLeod, and McCarty performed transformation experiments using live, harmless bacteria and extracts from virulent bacteria treated with various enzymes. Which of the following enzymes were used and why?

Proteases and RNases to rule out protein and RNa as the transforming factors

Once the pattern found after one round of replication was observed, Meselson and Stahl could be confident of which of the following conclusions

Replication is not conservative

If the nucleotide base sequence of one strand of a DNA molecule reads AACGGTGACTGG, then then complementary strand is

TTGCCACTGACC

In DNA replication, DNA polymerase catalyze the reaction in which

a nucleotide with a base complementary to the base on the template stand is added to the new DNA strand

The fact that the 3' to 5' end of one strand runs opposite to the 3' to 5' end of the other is the phenomenon of

antiparallelism

Changes in DNA in your cells ocurs frequently. Most of these changes are repaired EXCEPT WHEN

both DNA strands are damaged beyond recognition at the same time

In semiconservative DNA replication

each strand acts as the template for a complementary strand

https://apcentral.collegeboard.org/pdf/ap-biology-practice-exam-2013.pdf?course=ap-biology

metahphase

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A) metaphase B) anaphase C) prophase D) interphase

metaphase

Rosalind Franklin's x-ray diffraction images taken in the 1950s most directly support which of the following claims about DNA

the basic molecular structure is a helix