Fine Structure of the Chromosome

Question 1

type of DNA found in prokaryotes

Answer 1

closed circular covalently-bonded DNA (cccDNA)

Question 2

amount of DNA in a haploid genome

Answer 2

C-value

Question 3

C-Value Paradox

Answer 3

Phenomenon where neither total length of DNA nor number of chromosomes correlates strongly with perceived complexity of the organisms; The correlation between complexity and genome size is poor because most of eukaryotic DNA is non-coding.

Question 4

non-coding sequences

Answer 4

introns

Question 5

cap ends of linear chromosomes and are needed for successful cell division

Answer 5

telomeres

Question 6

where two daughter chromosomes are held together during mitosis

Answer 6

centromere

Question 7

components of yeast artificial chromosome (YAC)

Answer 7

yeast centromere, telomere, and replication origin

Question 8

end-replication problem of linear DNA

Answer 8

telomeres are shortened after each round of replication

Question 9

normal human cells divide about 52 times before losing ability to divide again

Answer 9

Hayflick limit

Question 10

Underwinding results in ____ supercoils

Answer 10

negative

Question 11

Overwinding results in ____ supercoils

Answer 11

positive

Question 12

These link sister chromatids after replication

Answer 12

cohesins

Question 13

fundamental organizational units of eukaryotic chromatin

Answer 13

nucleosomes

Question 14

also known as one-start helix

Answer 14

solenoid model

Question 15

also known as two-start helix

Answer 15

zigzag model

Question 16

Enumerate the levels of compaction of DNA in a eukaryotic chromosome

Answer 16

DNA (2nm) → nucleosome (11nm) → 30nm fiber → extended form of chromosome (300nm) → condensed section of chromosome (700nm) → mitotic chromosome (1,400nm)

Question 17

serve as points of attachment for microtubules that move chromosomes during cell division

Answer 17

kinetochores

Question 18

proteins that are important for structural and functional aspects of the centromere and kinetochore

Answer 18

centromere proteins (CENPs)

Question 19

Human centromeres are composed of _____.

Answer 19

repetitive alpha satellite DNA