Chapter 7 Flashcards Preview

AP Biology > Chapter 7 > Flashcards

Flashcards in Chapter 7 Deck (68):
1

Asexual Reproduction

making new individuals, common in nature

2

clones

the results of asexual reproduction

3

mutations

the only reason that there would be a change in genetic information in DNA replication

4

Sexual Reproduction

the fusion of two specialized cells called gametes

5

how do gametes form?

by meiosis

6

meiosis

a process of cell division, everything is randomly separated and reorganized so that the daughter cells differ from one another

7

chromosomes

daughter cells consist of chromosomes, they are made up of DNA and proteins

8

somatic cells

cells that are not specialized for reproduction, each contains two sets of chromosomes

9

homologous pairs

the pairs of chromosome sets in somatic cells

10

haploid

haploid gametes only have one homolog

11

zygote

two fused gametes in the process of fertilization

12

fertilization

the fusing of two gametes in meiosis.

13

diploid

after the gametes have fused, they have two sets of chromosomes, a homologous pair,

14

haplontic organisms

most protists, fungi, some green algae, they usually just spread their spores

15

alternation of generations

most plants and fungi go through this. form a haploid lifestage called a gametophyte

16

diplontic organisms

animals, plants, fungi, brown algae, the gametes are the only haploid cells in the life cycle. the mature organism is diploid

17

random selection of half of the diploid chromosome set

to make a haploid genome

18

reproductive signal

initiates cell division

19

replication of DNA

two new cells will have a full complement of genes

20

segregation

the cell must distribute the replicated DNA to each of the new cells

21

cytokinesis

the division of the cytoplasm to make two daughter cells. for this to happen, enzymes must be synthesized, new material must be added to the cell membrane

22

binary fission

this is how prokaryotes divide, the cell grows then it replicates its DNA, then it separates from the cytoplasm, and makes the DNA into two cells

23

replication of DNA

many times chromosomes are cicular, they are joined at the ends.

24

ori

the site where replication of the circular chromosome starts (the origin of replication)

25

ter

the site where replication ends (the terminus of replication)

26

replication complex

chromosome replication takes place as the DNA is threaded through a replication complex of proteins near the center of the cell, it begins at the ori and moves toward the ter. once they are done replicating, they can segregate

27

segregation

so replication begins near the center of the cell, then the ori moves toward the outside of the cell and the DNA binds to proteins adjacent to the ori.

28

cytokinesis

the division of a single cell into two cells begins in the cytoplasm. the fibers of the microtubules actually work to break the cells apart.

29

replication of DNA in eukaryotes

similar to replication in prokaryotes, occurs only at specific stages of lifecycle

30

segregation of DNA in eukaryotes

a copy of each chromosome must end up in each of the two new cells. they are super close to each other in eukaryotes, they become highly condensed, mitosis segregates them into two new nuclei.

31

mitosis

the proces that separates the chromosomes into two new nuclei in eukaryotic segregation, the cytoskeleton is involved

32

cytokinesis

follows mitosis, the literal breaking up of the two cells, always starts in the cytoplasm, different in plant and animal cells because animal cells have no cell walls

33

cell cycle

the period of one division to the next, in eukaryotes this is mitosis and cytokinesis, referred to as the M phase, and a much longer interphase

34

interphase of eukaryotes

the cell nucleus is visible and typical cell functions occur, including DNA replication in cells that are dividing

35

the three subphases of interphase

G1, S, and G2, the G stands for Gap

36

G1

quite variable, cell may spend a long time in this phase carrying out specialized functions

37

S phase

the cells DNA is replicated during this

38

G2

the cell makes preparations for mitosis, EX. like synthesizing components of the microtubules that will move teh segregating chromosomes to opposite ends of dividing cell

39

prophase

the appearance of the nucleus changes as the cell enters this stage, the beginning of mitosis

40

condensed chromosomes

each chromosome contains a very long double stranded DNA molecule

41

sister chromatids

after DNA each chromosome has two DNA molecules, they are held together at the centromere until separation during mitosis

42

centromere

where the two DNA molecules are held together until separation during mitosis

43

kinetochores

special proteins that assemble on the centromeres, one on each chromatid. important for chromosome movement

44

karyotype

constituted by size and number of chromosomes

45

centrosome

the central body

46

centrioles

the centrosome consists of a pair of these

47

spindle

Microtobules in the spindle apparatus that control chromosome movement

48

polar microtubules

Microtobules extending from the centrioles that overlap to form the spindle apparatus,

49

kinetochore microtubules

Microtubules extending from the centrioles to the chromosome kinetechores.

50

daughter chromosomes

the sister chromatids become after separation

51

prometaphase

the nuclear envelope breaks down and the compacted chromosomes, each consisting of two chromatids, attatch to kinetochore microtubules

52

metaphase

the chromosomes line up at the middle of the cell, the equatorial position

53

anaphase

the chromatids separate, the daughter chromosomes move away from each other toward the poles

54

telophase

occurs after the chromosomes have separated and is in the last phase of mitosis

55

animal cell cytokinesis

begins with furrowing of plasma membrane, it like threads through it, this is called the contractile ring

56

the contractile ring

composed of microfilaments of actin and myosin, form a ring on the cytoplasmic surface of the plasma membrane

57

plant cell cytokinesis

the cytoplasm divides differently because plants have cell walls

58

growth factors

mammals produce a variety of these, they stimulate cell division and differentiation, like when you cut yourself

59

G1-S transition

it marks a key decision point for the cell, if it passes the restriction point, it usually means that the cell will proceed with the rest of the cycle

60

the restriction point

the cell must pass this point or it is unlikely that it will finish the cycle

61

cell fusion

the merging of two or more cells into a single cell

62

cyclin dependant kinases

cell cycles that are dependant on protein kinases, they have to go through cdk checkpoints

63

cell cycle checkpoints

each cdk checkpoint has its own cyclin to activate it, it can only be made at the right time

64

what two things happen in meiosis?

crossing over and independant assortment

65

chiasma

the point where genetic material is exchanged between non sister chromatids on homologous chromosomes

66

crossing over

when genetic material is exchanged between nonsister chromatids on homologous chromosomes

67

recombination

what crossing over results in, its the recombination of chromatids, each increases in genetic variation among products of meiosis by reshuffling genetic information among homologous pairs

68

independant assortment

(genetics) The process of random segregation and assortment of chromosomes during anaphase I of meiosis resulting in the production of genetically unique gametes.