meiosis

Question 1

Genes

Answer 1

hereditary units - chromosomes contain many genes

Question 2

Locus

Answer 2

“place” on a gene. The specific location of a gene on a chromosome

Question 3

Sexual Reproduction

Answer 3

gametes with 2 different sets of genes combine to form new, genetically unique offspring
unique combination of genes = individual variations

Question 4

Asexual Reproduction

Answer 4

single individual provides exact copy of genetic material to offspring
creates clone

Question 5

Budding

Answer 5

• asexual outgrowth
• hydra (simple animal)
• redwoods

Question 6

Parthenogenesis

Answer 6

process by which offspring are created

Question 7

Genome

Answer 7

complete compliment of genes

Question 8

Homologous chromosomes

Answer 8

2 versions of a chromosome. Code for the same traits: each homolog contains information for the same traits

Question 9

Autosomes

Answer 9

all the other 22 pairs of chromosomes

Question 10

Diploid

Answer 10

2n = 2 copies of each chromosome

Question 11

Haploid

Answer 11

n = 1 copy of each chromosome

Question 12

Mitosis

Answer 12

maintain 46 chromosomes (2n)

Question 13

Meiosis

Answer 13

reduce chromosome to 23 (n)
take 1 homolog from parent to genome from gamete

Question 14

Meiosis 1

Answer 14

separates homologous chromosomes
(2 haploid daughter cells)

Question 15

Meiosis 2

Answer 15

separates sister chromatids
(4 haploid daughter cells)

Question 16

at end of meiosis 2 the cells are…

Answer 16

4 genetically haploid cells

Question 17

Synapsis

Answer 17

homologous chromosome line up

Question 18

Crossing Over

Answer 18

homologous chromosome

Question 19

chiasmata

Answer 19

point of contact between the homologous chromosomes (exchange of chromosomal segments take place)

Question 20

Meiosis 1: prophase 1

Answer 20

• chromosomes condense
• synapsis occur
• crossing over occurs
• chiasmata are apparent

Question 21

Meiosis 1: Metaphase 1

Answer 21

tetrads line up at the metaphase plate, with one chromosome facing each pole
- microtubules attach to kinetochores

Question 22

Meiosis 1: Anaphase 1

Answer 22

• pairs of homologous chromosomes separate, guided by spindle fibers
• sister chromatids remain attached at the centromere and move as one unit towards the pole

Question 23

Meiosis 1: Telophase 1 & Cytokinesis

Answer 23

• each half of the cell has a haploid set of chromosomes; each chromosome still consists of two sister chromatids

Question 24

Meiosis 2: Prophase 2

Answer 24

• spindle apparatus forms
• chromosomes (each still composed of two chromatids) move towards the metaphase plate

Question 25

Meiosis 2: Metaphase 2

Answer 25

• sister chromatids arrange at the metaphase plate
  (bc of crossing over in meiosis 1, sister chromatids are no longer identical)
• the kinetochores of sister chromatids attach to microtubules extending from opposite poles

Question 26

Meiosis 2: Anaphase 2

Answer 26

• sister chromatids separate
• sister chromatids of each chromosome now move as two newly individual chromosomes towards opposite poles

Question 27

Meiosis 2: Telophase 2 & Cytokinesis

Answer 27

• chromosomes arrive at opposite poles
• nuclei form, and the chromosomes begin to decondensing
  ( at the end of meiosis, there are 4 daughter cells, each with a haploid set of unduplicated chromosomes)

Question 28

Allels

Answer 28

different versions of genes

Question 29

3 processes that help with genetic variation

Answer 29

1) Independent assortment
2) crossing over
3) random fertilization

Question 30

Independent assortment

Answer 30

• arrangement of homologs at metaphase plate in metaphase 1 is random
• each homolog has a 50/50 chance of ending up in each daughter cell

Question 31

Crossing Over

Answer 31

genetic material is exchanged at the site of the chiasma