DNA And Chromosomes

Question 1

Evidence of when a cell is undergoing mitosis

Answer 1

• chromosomes are visible because they have condensed
• each chromosome is made up of two chromatids cuz DNA has replicated

Question 2

How does placing a cell in a solution w/ higher WP than cytoplasm move chromosomes apart?

Answer 2

• water moves into cell by osmosis
• cell gets bigger so chromosomes occupy space

Question 3

How can the structure of chromosomes differ along its length to result in the stain binding in more areas than some?

Answer 3

• difference in base sequences

Question 4

What is a homologous pair of chromosomes?

Answer 4

• two chromosomes that carry the same gene

Question 5

When a chromosome is affected why does all body cells have this mutation ?

Answer 5

• all cells derive from that single cell by mitosis
• mitosis produced genetically identical cells

Question 6

How can observing chromosomes from an embryonic cell help to determine sex?

Answer 6

• female: XX
• male: XY

Question 7

What is a haploid cell?

Answer 7

• cell w/ single complete set of unpaired chromosomes

Question 8

How is a gene the code for the production of a polypeptide?(3)

Answer 8

-base sequences
-in triplets
-determines 1’ in pp

Question 9

How does a phosphodiester bond form b/t 2 nucleotides w/in a DNA molecule? (3)

Answer 9

-condensation reaction
-b/t phosphate and deoxyribose
-by DNA polymerase

Question 10

Why might a mutation not cause a change in pp structure? (2)

Answer 10

-occurs in introns (non-coding seq)
-degenerate: triplets code for same aa