14.1 + 14.2

Question 1

goals of cell reproduction

Answer 1

1. pass the cells genetic info onto daughter cells
2. pass sufficient amount of cellular contents to insure daughter cell survial

Question 2

prokaryotic cells reproduce by binary fission

Answer 2

1. a copy of the cells DNA is created
2. cell elongates and septum forms
3. septum forms completely and daughter cells seperate

Question 3

eukaryotic cells reproduce by mitosis and cytokinesis

Answer 3

mitosis= nuclear division
cytokinesis= cytoplasmic divison
both rely on temporary cytoskeletal machines

Question 4

eukaryotic chromosomes

Answer 4

-different species have different numbers of chromosmes
-chromosome number is not correlated with organism complexity
-gain or loss of chromosomes is usually fatal

Question 5

karyotype

Answer 5

the array of chromosomes in a species or individual
-may be arranged according to size, straining properties, or other features

Question 6

haploid (1n)

Answer 6

complete set of chromosomes necessary to define the species

Question 7

diploid (2n)

Answer 7

2 complete sets of chromosomes
-usually orginate through sexual reproduction
-each parent provides one set
- the 2 copies are termed homologus
-each chromosome of a pair is a homolog

Question 8

eukaryotic chromosomes

Answer 8

-composed of chromatin (a complex of DNA and protein)
-each single chromosome is one continuous DNA molecule
-typical human chromosome is 140 milllion nucleotides
-a human cell contains 6 feet of DNA
- 2 types of chromatin are present in the nucleus (heterochromatin and euchromatin)

Question 9

heterochromatin

Answer 9

tightly packed and not expressed

Question 10

euchromatin

Answer 10

more loosely packed and able to be expressed

Question 11

DNA packagin

Answer 11

DNA-> nucleosome->solenoid-> mitotic chromsome

Question 12

nucleosome

Answer 12

DNA + histones 10nm fiber “beads on a string”

Question 13

solenoid

Answer 13

compacted 10nm fiber=> 30 nm fiber
usual interphase state