Meiosis definitions

Question 1

gamete

Answer 1

sex cells (sperm or egg/ovum) haploid cells

Question 2

somatic cell

Answer 2

body cells: all cells in the body except sex cells (diploid)

Question 3

haploid

Answer 3

a cell with half the number as parent cell, referred to as n

Question 4

diploid

Answer 4

twice the number of chromosomes in a gamete (2n). every cell of the body is diploid, except the sex cells. diploid # is 46

Question 5

sister chromatids

Answer 5

a chromosome and its duplicate attached to one another by the centromere

Question 6

centromere

Answer 6

structure that holds chromatids together

Question 7

homologous pair

Answer 7

paired chromosomes that are similar in size and gene arrangements but have different alleles

Question 8

tetrad

Answer 8

a pair of homologous chromosomes, each with sister chromatids

Question 9

gene

Answer 9

sections of DNA that contain genetic information for the inheritance of specific traits

Question 10

alleles

Answer 10

different forms of the same gene

Question 11

crossing over

Answer 11

the exchange of genetic material between homologous chromosomes

Question 12

what is the purpose of meiosis?

Answer 12

genetic reduction and genetic recombination

Question 13

genetic reduction

Answer 13

diploid to haploid

Question 14

genetic recombination

Answer 14

genetically distinct offspring, which increase genetic variation in a population

Question 15

explain spermatogenesis

Answer 15

it begins at puberty and spermatogonia reproduce by mitosis. they will undergo meiosis to produce 4 haploid sperm cells. at the end of meiosis II, the sperm cells undergo final changes to become functionally mature sperm.

Question 16

sperm

Answer 16

nucleus is organized into a head region, the midsection hold mitochondria to provide energy, and a long tail for movement

Question 17

explain oogenesis and what are the cells that dont mature

4 points

Answer 17

the oogonia reproduces by mitosis before birth and they begin meiosis but stop at prophase I. each month after puberty, one cell completes meiosis. the cytoplasm is unevenly distributed and only 1 cell matures, not 4. this is because the egg needs lots of nutrients to support a zygote if fertilization occurs. polar bodies

Question 18

crossing over

Answer 18

in prophase I only. when on chromosome from each parent is lined up, this is called synapsis and when the exchanging of genetic material occurs this is called crossing over

Question 19

independent assortment

Answer 19

occurs in metaphase I or II. when homologous chromosomes line up at the metaphase plate in a random order.

Question 20

meiosis I

Answer 20

separation of homologous chromosomes

Question 21

meiosis II

Answer 21

separation of sister chromatids

Question 22

meiosis II =

Answer 22

mitosis