10.1

Question 1

Describe the process of binary fission.

Answer 1

1. Single, circular bacterial chromosome is replicated
2. Replication begins at the origin of replication and proceeds in two directions to site of termination
3. New chromosomes are partitioned to opposite ends of the cell
4. Septation - mediated by FtsZ protein

Question 2

Define septation and its role during binary fission

Answer 2

Septum forms to divide the cell into 2

Question 3

Diploid (2n)

Answer 3

 23 in humans (egg and sperm)
 pairs of homologous chromosomes

Question 4

Haploid (n)

Answer 4

 One set of chromosomes
 46 total chromosomes

Question 5

Heterochromatin

Answer 5

not expressed, compact

Question 6

Euchromatin

Answer 6

expressed, non-compact

Question 7

Identify the levels of chromosome packing

Answer 7

Order of packing: nucleosome -> solenoid (30 nm fiber) -> rosettes (scaffold proteins) -> compact chromosome

Question 8

homologous chromosomes

Answer 8

came from mom and dad - pairs of chromosomes

Question 9

Sister chromatids

Answer 9

duplicated chromosome

Question 10

Nonreplicated chromosomes

Answer 10

one DNA molecule – this is prior to S phase in cell cycle

Question 11

Replicated chromosomes

Answer 11

2 identical DNA molecules (sister chromatids) attached at the centromere (butterfly) - happens during S phase

Question 12

Describe the eukaryotic cell cycle.

Answer 12

o Interphase
 Gap 1 (growth, primary, longest phase)
 S phase (synthesis phase , replication of DNA (chromosome duplication)
 Gap2 (organelles replicate, microtubules organize)
o M phase - the process of actual cell division
 Prophase
 Prometaphase
 Metaphase
 Anaphase
 Telophase
 cytokinesis

Question 13

chromatid

Answer 13

individual

Question 14

chromosome

Answer 14

can be replicated or nonreplicated