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Flashcards in Chromosomes & The Cell Cycle Deck (46)
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1
Q

Prokaryote vs. eukaryote chromosomes

A

Prokaryote: short and circular

Eukaryote: long and linear

2
Q

Prokaryote basics

A

no nucleus

Single celled

Always haploid

3
Q

Eukaryote basics

A

Have a nucleus

Some single celled, some multicellular

Both haploid and diploid

4
Q

Every cell has it’s own ____ and can be ___ or ___

A

Genes, haploid, diploid

5
Q

Haploid definition

A

1 copy of every gene

6
Q

Diploid

A

2 copies of every gene

1 from mom and 1 from dad

7
Q

Mitosis definition

A

Cell division that makes 2 daughter cells identical to the mother cell–whether haploid or diploid

8
Q

Meiosis definition

A

Cell division that splits diploid cells into haploid cells

9
Q

Cell division in prokaryotes

A

Very simple–circular haploid chromosome of DNA duplicates, then cell splits in two

Result: 2 identical haploid daughter cells

10
Q

Human diploid cell chromosome #

A

23 pairs, or 46 chromosomes

11
Q

After DNA duplication, Human diploid cell chromosome #

A

23 pairs, or 46 chromosomes

BUT each chromosome has a sister chromatid = 92 chromatids in the cell

12
Q

When the cell is about to divide it first…

A

Duplicates chromosomes

13
Q

After duplication of chromosomes…

A

Each chromosome consists of 2 sister chromatids

14
Q

What is a chromosome?

A

A strand of DNA that carries genetic info in a cell

15
Q

Human haploid and diploid #s

A

Haploid (N) = 23

Diploid (2N) = 46

16
Q

spindle fiber

A

long protein molecule (microtubule) that tows chromosomes during division

17
Q

centromere

A

area of a chromosome where spindle fibers attach during division

18
Q

kinetochore

A

protein structure on a centromere where spindle fibers attach

19
Q

centrosome

A

the structure (centriole + aster) where microtubules pull the chromosomes

aka. microtubule organizing center (MTOC)

20
Q

centriole

A

strange little cylinder made of short microtubules

located at the center of a centrosome

21
Q

aster

A

cluster of spindle fiber

converge at centrosome

22
Q

bands on chromosomes

A

numbered in both directions starting at centromere

only visible when chromosomes are stained with a special technique

23
Q

the earlier in ___ the longer the chromosomes are, and more bands are ____

A

prophase, visible

24
Q

karyotype

A

visual of a person’s 23 chromosome pairs

25
Q

during the mitotic cell cycle a human cell has how many chromosomes?

A

46 (23 pairs)

26
Q

during the mitotic cell cycle is a human cell always diploid?

A

yes

27
Q

interphase

A

happens between cell divisions

chromosomes are decondensed and invisible

3 stages (G1, S, G2)

28
Q

G1

A

each chromosome consists of 1 chromatid

29
Q

S

A

DNA is duplicated

30
Q

G2

A

each chromosome consists of 2 chromatids

31
Q

G0

A

some cells exist in this state of non-division

may be permanent (nervous cells) or reversible (immune cells)

32
Q

at what stage can you see a karyotype?

A

at the end of G2 in interphase

33
Q

cytokinesis

A

dividing the cytoplasm and membrane

34
Q

at mitosis the cell splits each _____ into _____

A

2-chromatid chromosome, single-chromatid chromosomes

35
Q

higher plants don’t have…

A

centrioles

36
Q

the haploid number of chromosomes is called __ and the diploid number is called ___

A

N, 2N

37
Q

in simple eukaryotes the ___ stage of life is dominant

A

haploid

38
Q

fungi spend most of their lives as ____

A

haploids, growing as little invisible threads called mycelia

39
Q

more complex plants spend most of their lives as ___

A

diploids

40
Q

animals spend their whole lives as ____ except for the _____ stage

A

diploids, gamete

41
Q

the diploid stage of any eukaryote begins with ____

A

syngamy: when two haploid gametes combine to form a diploid cell

42
Q

meiosis can only occur in the ___ stage because…

A

diploid

it requires a cell with pairs of homologs

43
Q

what are the two types of cells in animals in the diploid stage?

A

somatic and germline

44
Q

somatic cells

A

everything other than germline

only go through mitosis

45
Q

germline cells

A

exist only in the gonads (testes & ovaries)

go through either mitosis OR meiosis

46
Q

what is the important function of meiotic recombination?

A

to shuffle the genes, making new chromosomes with new combinations of parental alleles