Mcat Biology Lecture 2

Front 1

If during anaphase I or II the centromere of any chromosome does not split this is called ___.

Back 1

nondisjunction

Front 2

____ a nuclear membrane may or may not reform & cytokinesis may or may not occur.

Back 2

telophase I

Front 3

meiosis I is ____.

Back 3

reduction division

Front 4

meiosis II -

Back 4

proceeds w/ prophase II, metaphase II, anaphase II & telophase II apearing under a light microscope like normal mitosis.

Front 5

___ the homologues remain attached & move to the metaphase plate. tetrads align in meiosis.

Back 5

metaphase I

Front 6

Genes located close together on a chromosome are more likely to cross over together and are said to be ___.

Back 6

Linked

Front 7

chiasma

Back 7

"x" shape

Front 8

tetrads

Back 8

x shape, has (4) chromotids (46) chromosomes

Front 9

spermatagonium
oogonium

Back 9

gonna be a sperm
gonna be an egg

Front 10

diploids = ____

Back 10

homologues

Front 11

____ - a process of genetic recombination in which homologous chromosomes may exchange sequences of DNA nucleotides.

Back 11

crossing over

Front 12

meiosis is like ___, except in ___ there are ___ rounds, the daughter cells are ____ & ____ occurs.

Back 12

mitosis
mitosis
2
haploid
genetic recombination

Front 13

oogonium development

Back 13

1. oogonium (haploid)
2. primary oocyte (haploid)
3. 2nd oocyte (diploid) and polar bodies
4. more polar bodies
5. join w/ sperm and zygote (haploid)

Front 14

spermatagonium development

Back 14

1. spermatagonium (diploid)
2. primary spermatocyte (diploid)
3. 2ndary spermatocyte (haploid)
4. spermatatids (haploid)
5. spermatazoa (haploid)

Front 15

meiosis has ___ rounds of division called ___ & ____.

Back 15

2
meiosis I
meiosis II

Front 16

after replication occurs in the S phase of interphase, the cell is called ____ or ___. (m or f)

Back 16

primary spermatocyte
primary oocyte

Front 17

In humans only ____ & the ____ undergo meiosis. All other cells are ___ & undergo ____ only.

Back 17

spermatagonium
oogonium
somatic cells
mitosis

Front 18

meiosis-

Back 18

a double nuclear division which produces 4 haploid gametes.

Front 19

gametes -

Back 19

germ cells

Front 20

____ - a structure of protein & DNA located at the centromere of the joined chromatids of each chromosome.

Back 20

kinetochore

Front 21

microtubles radiating from the centrioles

Back 21

Aster

Front 22

a group of proteins located toward the center of the chromosome.

Back 22

centromeres

Front 23

____ is characterized by the condensation of chromatin into chromosomes. centrioles move to the opposite ends of the cell. first the nucleolus and then the nucleus disappear. the spindle apparatus begins to form connecting the two centrioles.

Back 23

prophase

Front 24

____ - begins when sister chromatids split at their attaching centromeres & move toward opposite ends of the cell. This split is termed disjunction. Cytokinesis, the actual separation of the cellular cytoplasm due to constriction of microfilaments about the center of the cell, may commence toward the end of this phase.

Back 24

anaphase

Front 25

____ chromosomes align along the equator of the cell.

Back 25

metaphase

Front 26

mitosis -

Back 26

nuclear division w/o genetic change
4 stages (pmat)
prophase
metaphase
anaphase
telophase

Front 27

___ - the cell has just split & begins to grow in size.
The cell must reach a certain size & synthesize sufficient protein in order to continue to the next stage.

Back 27

g1 phase

Front 28

___ - the cell prepares to divide
The ___ checkpoint checks for mitosis promoting factor (MPF). When the level of MPF is high enough, mitosis is triggered.

Back 28

g2 phase
g2

Front 29

___ - the cell devotes most of its energy to replicating DNA.
Each chromosome is exactly duplicated. The cell still has the same number of chromosomes (46); only now each chromosome is made of 2 identical sister chromatids.

Back 29

s phase

Front 30

___ - a nongrowing state distinct from interphase.

Back 30

g0 phase

Front 31

Interphase -

Back 31

g1, S & g2 phases collectively

Front 32

Cell life cycle -

Back 32

g1 - 1st growth phase
s - synthesis
g2 - 2nd growth phase
M - mitosis or meiosis

Front 33

The chromatin associated w/ each one of these (46 double stranded DNA) molecules is called a _____.

Back 33

chromosome

Front 34

human somatic cell has ___.

Back 34

46 double stranded DNA molecules.

Front 35

haploid -

Back 35

w/o homologues

Front 36

diploid -

Back 36

w/ homologues

Front 37

Chromatin -

Back 37

the entire dna/protein complex
by mass chromatin is only about 1/3 DNA, 2/3 protein and a small amount of RNA.

Front 38

8 histones wrapped in DNA form a ___.

Back 38

nucleosome

Front 39

The sections of DNA that are not in use are wrapped tightly around globular proteins called ____.

Back 39

histones

Front 40

in ___, DNA is found only in the ___ & the ____.

Back 40

Animals
nucleus
mitochondria