Biology: Chapter 15

Front 1

the field of genetics that involves the microscopic examination of chromosomes

Back 1

cytogenetics

Front 2

reveals the number, size, and form of chromosomes found within an actively dividing cell

Back 2

karyotype

Front 3

the two copies of chromosomes that have already replicated

Back 3

sister chromatids

Front 4

the chromosomes tat are not sex chromosomes

Back 4

autosomes

Front 5

humans ave ---- different types of autosomes

Back 5

22

Front 6

when an organism carry two sets of chromosomes, that organism is said to be ___

Back 6

diploid

Front 7

human cells that are haploid

Back 7

sperm and egg cells (1n)

Front 8

the members of a pair of chromosomes from a diploid

Back 8

homologs

Front 9

the sperm and egg cells are referred to as ______

Back 9

gametes

Front 10

the phases of the cell cylce

Back 10

G1 (first gap)

S (synthesis of DNA)

G2 (second gap)

M phase (mitosis and cytokinesis)

Front 11

collectively known as interphase

Back 11

G1

S

G2

Front 12

during ______ the cell grows and copies its chromosomes in preparation for cell division

Back 12

interphase

Front 13

is a nondividing phase

Back 13

G0

Front 14

during this phase, each chromosome is replicated to form a pair of sister chromatids

Back 14

S phase

Front 15

during this phase, a cell synthesizes the proteins necessary for chromosome sorting and cell division

Back 15

G2 phase

Front 16

the division of the cytoplasm to produce two distinct daughter cells

Back 16

cytokinesis

Front 17

the division of once cell nucleus into two nuclei

Back 17

mitosis

Front 18

proteins responsible for advancing a cell through the phases of the cell cycle

Back 18

cyclins

cyclin-dependent kinases (cdks)

Front 19

when is G1 cylcin degraded?

Back 19

after the cell passes into S phase

Front 20

accumulates late in G2; binds to a cdk to form an activated mitotic cyclin/cdk complex

Back 20

mitotic cyclin

Front 21

this complex phosphorylates proteins that are needed to advance the cell into M phase

Back 21

mitotic cyclin/cdk complex

Front 22

these proteins act as sensors to determine if a cell is in the proper condition to divide

Back 22

checkpoints

Front 23

aka G1 checkpoint -- can sense if the DNA has incurred damage

Back 23

restriction point

Front 24

monitors the levels of proteins that are needed to progress through M phase

Back 24

G2 checkpoint

Front 25

senses the integrity of the spindle apparatus

Back 25

metaphase checkpoint

Front 26

a process in which genetically identical offspring are produced from a single parent

Back 26

asexual reproduction

Front 27

a structure necessary for sorting each chromosome

Back 27

kinetochore

Front 28

responsible for organizing and sorting the chromosomes during cell division

Back 28

mitotic spindle

Front 29

aka MTOC - microtubule organizing centers

Back 29

centrosomes

Front 30

3 types of spindle microtubules

Back 30

astral - positions the spindle apparatus

polar - separates the two poles

kinetochore -- sorts each chromosome

Front 31

observed mitosis in 1871

Back 31

Walther Flemming

Front 32

in this phase the mitotic spindle is fully formed; centrosomes move apart and demarcate the two poles

Back 32

prometaphase

Front 33

the pairs of sister chromatids are aligned in a single row during this phase

Back 33

metaphase

Front 34

during this phase, the chromosomes have reached their respective poles and decondense

Back 34

telophase

Front 35

the connections between the pairs of sister chroatids are broken

Back 35

anaphase

Front 36

constriction of cells like a drawstring to separate the cells

Back 36

cleavage furrow

Front 37

forms a cell wall between the two daughter cells

Back 37

cell plate

Front 38

occurs when two nuclei are segregated into separate daughter cells

Back 38

cytokinesis

Front 39

what are the results of mitosis and cytokinesis?

Back 39

production of two daughter cells with the same number of chromosomes as the mother cell

ensures genetic consistency from once cell to the next

Front 40

approximately ___ proteins are involved with cytokinesis

Back 40

20

Front 41

the 20 conserved proteins perform 4 functions :

Back 41

contractile ring

signal transduction

central spindle

cell separation via membrane insertion

Front 42

when two haploid gametes unite, it forms a _____

Back 42

zygote

Front 43

the process by which haploid cells are produced from a cell that was originally diploid

Back 43

meiosis

Front 44

in meiosis, sister chromatids associate with each other forming a____

Back 44

bivalent (aka tetrad)

Front 45

the process of forming a bivalent

Back 45

synapsis

Front 46

involves a physical exchange between chromosome segments of the bivalent

Back 46

crossing over

Front 47

the ____ becomes visible as chromosome arms separate during late prophase

Back 47

chiasma

Front 48

2 key events that occur at the beginning of meiosis that do not occur in mitosis

Back 48

bivalent formation

crossing over of chromosome segments

Front 49

the sequence of events that produces another generation of organisms

Back 49

life cycle

Front 50

animals are ______

Back 50

diploid-dominant species

Front 51

most fungi and some protists are _____

Back 51

haploid-dominant species

Front 52

plants and algae are -______

Back 52

alternation of generations

Front 53

the species of plants and algae alternate between diploid multicellular organisms called _______, and haploid multicellular organisms called _________

Back 53

sporophytes

gametophytes

Front 54

animals produce gametes by ______

Back 54

meiosis

Front 55

plants and fungi produce reproductive cells by ______

Back 55

mitosis

Front 56

chromosomal mutations are categorized into four:

Back 56

deletions

duplications

inversions

translocations

Front 57

organisms that have chromosomes that occur in ore or more complete sets

Back 57

euploid

Front 58

organisms with three or more sets of chromosomes

Back 58

polyploid

Front 59

refers to an alteration in the number of particular chromosomes, so the total number of chromosomes is not an exact multiple or set

Back 59

aneuploidy

Front 60

refers to an event in which the chromosomes do not separate properly during cell division

Back 60

nondisjunction

Front 61

in which phase of the cell cycle are chromosomes replicated?

Back 61

S phase

Front 62

if 2 chromosomes are homologous, they:

Back 62

look similar under a microscope

have very similar DNA sequences

carry the same types of genes

may carry different versions of the same gene

Front 63

checkpoints during the cell cycle are important because they:

Back 63

ensure the integrity of the cell's DNA

Front 64

what are reasons for mitotic cell division

Back 64

asexual reproduction

multicellularity

Front 65

the nuclear envelope breaks down in what phase of mitosis?

Back 65

prophase

Front 66

what phase is the cell in?

2N (n=7)

the cell has 7 replicated chromosomes

sister chromatids are aligned at the metaphase plate of the cell

Back 66

metaphase of meiosis II

Front 67

a replicated chromosome is composed of

Back 67

two sister chromatids held together at the centromere

Front 68

aneuploidy may be the result of:

Back 68

nondisjunction during meiosis