Chromosome Structure and Packing

Question 1

What is a genome?

Answer 1

sum total of an organism’s genetic information

Question 2

What is a chromosome?

Answer 2

each piece of double stranded DNA

Question 3

How many chromosomes do humans have?

Answer 3

46, 23 from each parents

Question 4

What do prokaryotic genomes look like?

Answer 4

single circular chromosome

Question 5

What do viral genomes look like?

Answer 5

circular or linear RNA or DNA

Question 6

What is DNA gyrase?

Answer 6

protein in prokaryotes that uses ATP energy to twist the circular genome to make it more compact

Question 7

What are the twists called that DNA gyrase forms?

Answer 7

supercoils

Question 8

What is the flow of DNA structure in the nucleus from start to completely packaged?

Answer 8

Deoxyribose → add a base → nucleoside → add three phosphates → nucleotide → polymerize with loss of two phosphates → oligonucleotides → continue polymerization → single-stranded polynucleotide → two complete chains H-bonded antiparallel → ds DNA chain → coiling occurs → ds helix → wrap around histones → nucleosomes → complete packaging → chromatin

Question 9

What are the dark regions called when DNA is stained?

Answer 9

heterochromatin

Question 10

What are the lighter regions called when DNA is stained?

Answer 10

euchromatin

Question 11

What is the Giemsa stain?

Answer 11

staining that produces G-banding patterns used to produce karyotypes