Chapter 2: chromosome and cellular reproduction

Question 1

what happens before cell division

Answer 1

-dna chromosome replicates, after replication there are two copies of sister chromatids

Question 2

what are some characteristics of a prokaryotic cell

Answer 2

• pro does not have a nuclear membrane or nuclues
• cell is small
• one circular dna
• no membrane bound organelles

Question 3

what are some characteristics of a eukaryotic cell

Answer 3

• nucleus is present
• cell is big and complex
• large dna
• membrane bound organelles

Question 4

what is binary fission

Answer 4

asexual reproduction where a parent cell divides into 2 identical cells used by bacteria and archea

Question 5

what is the process for cell reproduction in bacteria

Answer 5

1. pro cell contains one single circular chromosome that is made of double stranded dna
2. as the chomosomes replicate the origins segreagate to opposite sides
3. the cell divides into identical copies

Question 6

what is the origin of replicaiton

Answer 6

it is where the dna sequence begins replication

Question 7

LO 2.6: describe what a diploid organism is and what homologous chromosomes are

Answer 7

1. diploid organism has 2 sets of chromosomes
2. homologous chromosomes have the same genes and one comes from mom and one set comes from dad

Question 8

what are sister chromatids

Answer 8

two identical copies of a chromosome that are formed by dna replication

Question 9

how many pairs of chromosomes does a human have

Answer 9

23

Question 10

how many total chromsomes does a human have

Answer 10

46 chromosomes

Question 11

what are the stages of the cell cycle before mitosis

Answer 11

interphase which is g1, s phasee, g2 phase

Question 12

where does the cell spend most of its time in the cell cycle and what happens during that stage

Answer 12

in interphase and it is where cell growth happens

Question 13

what happens in the mitosis phase

Answer 13

nuclear and cell divison

Question 14

what is the purpose of mitosis

Answer 14

to produce 2 genetically identical cells

Question 15

what is the purpose of meiosis( gametogeneis)

Answer 15

to create gametes for sexual reproduciton

Question 16

what are the results of meiosis

Answer 16

4 genetically variable cells who have 1/2 chromosome numbers

Question 17

what is one difference between meiosis 1 and meiosis 2

Answer 17

reduction divison: chromosome number is 1/32 and then equational division” similar to mitosis

Question 18

what is interkinesis

Answer 18

the stage that is in between meiosis 1 and meiosis 2 and it is when the chromosomes become relaxed and the nuclear membrane begins to form again

Question 19

what happens in prophase 1 of meiosis

Answer 19

• chromosomes condense.
  -crossing over takes place
• nuclear membrane breaks down
• miotic spindle forms

Question 20

metaphase 1

Answer 20

• homolog chromosomes line up on the metaphase plate

Question 21

anaphase 1

Answer 21

homolog chromsomes separate and go toward opposite poles

Question 22

telophase 1

Answer 22

chromosomes arrive at the spindle poles

Question 23

cytokinesis 1

Answer 23

cytoplasm divides to produce two cells each having halve the og number

Question 24

prophase 2

Answer 24

• chromosome condense
• spindle forms
• nuclear memebrane disentegrates

Question 25

metaphase 2

Answer 25

sister chromatids line up on the metaphase plate

Question 26

anaphsae 2

Answer 26

sister chromatids separate and the individual chromosomes move toward opposite poles

Question 27

telophase 2

Answer 27

chromosomes arrive at the spindle poles
- spindle breaks down and a nuclear envelope forms

Question 28

how is genetic variation created in meiosis

Answer 28

through crossing over and random distribution of chromiosomes during metaphase 1

Question 29

how does cohesin control the separation of chromatids and chromosomes in mitosis and meiosis

Answer 29

cohesin holds the homologous chromosomes together st th chiasmata and it can also break down so that the homologs to separate

Question 30

when does male spermatogenesis occur

Answer 30

from puberty through adulthood
- produces 4 sperm cells for each round of meiosis

Question 31

when does female oogenesis begin

Answer 31

prior to birth and is not complete until after fertilization
- 1 egg is produced for each round of meiosis