Regular Homework #5 Bio 111 - Gen Mager BSU (Mastering Biology)

6. a. What catalyzes DNA synthesis?

DNA polymerase

7. d. Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments?

DNA polymerase can assemble DNA only in the 5' to 3' direction

8. a. Which of these phases encompasses all of the stages of mitosis but no other events?

E

6. f. Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis?

Topoisomerase

6. g. True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.

True

1. a. Does the distribution of bases in sea urchin DNA and salmon DNA follow Chargaff's rules?

Yes, because the %A approximately equals the %T and the %G approximately equals the %C in both species.

1. d. If Chargaff's equivalence rule is valid, then hypothetically we could extrapolate this to the combined genomes of all species on Earth (as if there were one huge Earth genome). In other words, the total amount of A in every genome on Earth should equal the total amount of T in every genome on Earth. Likewise, the total amount of G in every genome on Earth should equal the total amount of C in every genome on Earth. Calculate the average percentage for each base in your completed table. Do Chargaff's equivalence rules still hold true when you consider those six species together?

Yes, the average for A approximately equals the average for T, and the average for G approximately equals the average for C.

7. b. After DNA replication is completed, _____.

each new DNA double helix consists of one old DNA strand and one new DNA strand

8. c. During _____ the cell grows and replicates both its organelles and its chromosomes.

interphase

9. a. Nucleoli are present during _____.

interphase

7. a. Short segments of newly synthesized DNA are joined into a continuous strand by _____.

ligase

7. c. The action of helicase creates _____.

replication forks and replication bubbles

9. b. Cytokinesis often, but not always, accompanies _____.

telophase

7. e. An old DNA strand is used as a _____ for the assembly of a new DNA strand.

template

8. b. During _____ both the contents of the nucleus and the cytoplasm are divided.

the mitotic phase

9. f. During prophase a homologous pair of chromosomes consists of _____.

two chromosomes and four chromatids

9. e. Spindle fibers attach to kinetochores during _____.

prometaphase

9. c. Chromosomes become visible during _____.

prophase

1. b. What is the %T in wheat DNA?

Approximately 28%

6. c. Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis?

Phosphate groups

6. d. Which of the following enzymes creates a primer for DNA polymerase?

Primase

6. b. Which of the following statements about DNA synthesis is true?

Primers are short sequences that allow the initiation of DNA synthesis.

13. c. Assume that an organism exists in which crossing over does not occur, but that all other processes associated with meiosis occur normally. Consider how the absence of crossing over would affect the outcome of meiosis. If crossing over did not occur, which of the following statements about meiosis would be true? Select all that apply.

There would be less genetic variation among gametes.

6. e. Which of the following statements about Okazaki fragments in E. coli is true?

They are formed on the lagging strand of DNA.

9. d. Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

anaphase