University:
University of Cincinnati
Course:
BIOL 2084C | Evolution and Ecology
Academic year:

2023
Views:

486

Pages:

2
Author:

Emilee Donaldson

Essential Biology DNA Replication 1. Identify the phase of the cell cycle during which DNA replication occurs. Answer: Interphase; also known as the S-phase 2. State the function of DNA replication. Answer: Copying DNA to produce new molecules with the same base sequence 3. Identify the end product of DNA replication in a human somatic cell. a) 23 chromosomes b) 46 chromosomes c) 23 pairs of chromosomes d) 23 pairs of sister chromatids 4. Describe how mitosis ensures that each new daughter cell is identical (mitosis review). Answer: • • When cells divide through mitosis, each daughter cells contains full set of DNA Mitosis ensures the daughter cells to get the correct number of each chromosome during metaphase and anaphase (separation of chromatids by the spindle microtubules.) • Once cell is divided through cytokinesis, full sets of chromosomes get produced on each pole, forming a new nucleus 5. Explain the process of DNA Replication: Answer: i. - ii. DNA Helicase unwinds and unzips the DNA double helix: Helicase Hydrogen bonds broken Bases exposed Parent strand Parent strand DNA polymerase creates complementary strands: Free nucleotides: are collected by DNA polymerase, attached to new strand by complementary base pairing - Parent strand DNA Polymerase moves in opposite directions on each strand - Complementary strands Parent strand 6. Explain the importance of complementary base pairing in conserving the base-sequence during DNA Replication Answer: • • • Ensures identical copies of DNA Base sequence of nucleotides conserved Mistake in gene expression could be fatal to organism 7. Describe why DNA replication is considered ‘semi-conservative’. Answer: - Produces two copies that each contain one original strand and one new copied strand. New strands Replicate Unzip Unwind Parent strand Copied (complementary) strand Copied (complementary) strand Parent strand -