Chapter 8 (PART 2) Flashcards Preview

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Flashcards in Chapter 8 (PART 2) Deck (22):
1

***Diploid =

2n = 2 sets of CHROMOSOMES

2

***Germ cells are ____ goin in, end of mitosis they're half way _______

diploid / gametes

3

***Haploid =

1n = 1 copy of chromosomes

4

Meiosis

-cell division that reduces a diploid cell’s chromosome # by HALF, producing haploid GAMETES

5

Homologous Chromosomes***

-PAIRS of similar chromosomes, one from each parent

6

-each species has a characteristic...

# of chromosomes

7

W/O meiosis, chromosome #’s

grow dramatically

8

Meiosis includes one round of chromosome replication flowed by _____ divisions

TWO cell divisions

9

In Meiosis l...

diploid parent cell divides to produce TWO HAPLOID daughter cells containing REPLICATED chromosomes

-ONLY time you have homologous pairing

-2 members of each homo pair are SEPARATED

10

Meiosis ll

-sister chromatids are SEPARATED

11

Down Syndrome is the result of having...

-3 copies of chromosome 21

-2 copies come from egg, ONE copy from sperm

12

Nondisjunction

-too many or too few chromosomes

-place in Meiosis l

13

Mitosis leads to ____ genetically identical daughter cells

TWO

14

Genetic variation arises through ______ ________ during Meiosis 1

genetic recombination

15

Crossing Over (c/o)

-trade parts btwn. homo chromosomes

-gives chance of more combinations

16

Independent Assortment

-chromosomes are given randomly along the equator of cell

-more combinations of MAternal & PAternal traits

17

Number of possible combinations of chromosomes is 2n, where “n” is the ______ #

haploid #

18

Resulting variations in offspring produce differences in...

fitness, raw material which natural selection acts

19

_______ reproduction may be advantage in constant environments

Asexual

20

Genetic variability made by _____ _______ may be helpful in CHANGEABLE environments

sexual reproduction

21

Mitosis accomplishes 2 things...

1) reproduction of cells

2) equal issuing of DNA to each daughter cell

22

Meiosis accomplishes 3 things:

1) reduces # of chromosomes by HALF so won't be doubled during fertilization

2) c/o allows new combinations of maternal & paternal traits

3) provides more combinations of MAternal & PAternal traits