Question

t4. hydrogen bonds connect base pairs in dna.
a. true
b. false
t5. mutations always result in harmful effects.
a. true
b. false
section 2: dna replication & mitosis
multiple choice questions (1 point each):

1. what is the role of dna polymerase?

• a. unzips dna
• b. synthesizes rna
• c. adds nucleotides
• d. repairs dna

1. what doessemiconservative replication mean?

• a. dna is not copied
• b. one strand is new, one is old
• c. both strands are new
• d. dna is degraded

1. which phase of mitosis involves chromosome alignment?

• a. prophase
• b. metaphase
• c. anaphase
• d. telophase

1. which process occurs in prokaryotes for cell division?

• a. mitosis
• b. meiosis
• c. binary fission
• d. cytokinesis

1. what is the function of cell cycle checkpoints?

Explanation:

• T4: In DNA, hydrogen bonds connect base pairs (e.g., adenine - thymine has two hydrogen bonds, guanine - cytosine has three hydrogen bonds).
• T5: Mutations can be neutral (e.g., silent mutations that don't change the amino acid sequence due to the degeneracy of the genetic code), beneficial (e.g., mutations that lead to antibiotic resistance in bacteria), or harmful. So, mutations don't always have harmful effects.
• Section 2 - 1: DNA polymerase adds nucleotides to the growing DNA strand during DNA replication. Helicase unzips DNA, RNA polymerase synthesizes RNA, and there are specific repair enzymes for DNA repair.
• Section 2 - 2: Semiconservative replication means that each new DNA molecule consists of one old (parental) strand and one new strand.
• Section 2 - 3: In metaphase of mitosis, chromosomes align at the metaphase plate.
• Section 2 - 4: Prokaryotes divide by binary fission. Mitosis and meiosis occur in eukaryotes, and cytokinesis is the process of cytoplasmic division (occurs in both prokaryotes and eukaryotes but is not the main process of cell division in prokaryotes like binary fission is).

Answer:

T4: A. True
T5: B. False
Section 2 - 1: C. Adds nucleotides
Section 2 - 2: B. One strand is new, one is old
Section 2 - 3: B. Metaphase
Section 2 - 4: C. Binary fission