Chapter 8

Question 1

why do cells reproduce?

Answer 1

growth (repair, replacement), sexual reproduction, asexually

Question 2

summary of important events that take place

Answer 2

cell cycle

Question 3

does a cell constantly divide?

Answer 3

no

Question 4

do ALL cells divide?

Answer 4

no

Question 5

75% of a cells life is spent in this phase with no active cell division

Answer 5

interphase

Question 6

STAGE OF INTERPHASE:
Cellular growth
• DNA supervises work of the
cell
• Metabolism occurs
• Cells breathe & “eat”

Answer 6

G1

Question 7

STAGE OF INTERPHASE:
• DNA replication occurs
• Chromosomes are duplicated,
forming identical sister
chromatids joined at the
centromeres

Answer 7

S

Question 8

STAGE OF INTERPHASE:
• More cellular growth
• Chromosomes are still inside
nucleus
• Chromosomes are not visible,
because DNA is still relaxed

Answer 8

G2

Question 9

colonial cell division where two identical daughter cells are produced from a parent cell

Answer 9

mitosis

Question 10

what happens during prophase?

Answer 10

chromosomes condense
centrioles replicate
nuclear membrane is broken
spindle fibers are formed and attach to duplicated chromosomes at the centromere

Question 11

what happens during metaphase?

Answer 11

duplicated chromosomes are lined up along the equatorial plate

Question 12

what happens during anaphase?

Answer 12

spindle fibers contract and pull molecules of DNA apart; they are now unduplicated chromosomes

Question 13

what happens during telophase?

Answer 13

chromosomes decondense and formation of a new nuclear membrane; cytokinesis takes place

Question 14

division of the cytoplasm

Answer 14

cytokinesis

Question 15

what do animal cells do during cytokinesis?

Answer 15

furrow

Question 16

what do plant cells do during cytokinesis?

Answer 16

cell plate is formed

Question 17

when cells divide out of control and regions of abnormal growth are formed

Answer 17

tumor

Question 18

tumor that is harmless and typically stays in one place

Answer 18

benign

Question 19

cancerous tumor, typically spreads or migrates

Answer 19

malignant

Question 20

involves two rounds of division and results in the production of four genetically distinct daughter cells

Answer 20

meiosis

Question 21

sex cells

Answer 21

gametes

Question 22

sex is a source for what genetically?

Answer 22

genetic variation

Question 23

what are the similarities between mitosis and meiosis?

Answer 23

involve cell division

have similar stages with similar names

Question 24

body cells that don’t make gametes

Answer 24

somatic cells

Question 25

somatic cells reproduce by what? mitosis or meiosis?

Answer 25

mitosis

Question 26

capable of replicating by mitosis; also produces gametes by meiosis

Answer 26

germ cells

Question 27

what are the difference between mitosis and meiosis?

Answer 27

MITOSIS ONLY: occurs in the somatic and germ cells and produce two genetically identicle daughter cells MEIOSIS: occurs only in germ cells and results in production of 4 genetically distinct gametes

Question 28

before division in meiosis what will a cell go through?

Answer 28

G1, S, G2

Question 29

what happens in prophase 1?

Answer 29

``` DNA condenses formation of spindle fibers duplicated centrioles *pairing of homologous chromosomes known as synapsis this forms tetrods nuclear envelope breaks down crossing over @ chiasmata *recombination (switch places) spindle fibers attach @ centrioles and move the pairs ```

Question 30

what happens in metaphase 1?

Answer 30

spindle fibers lineup chromosome pairs along the equatorial plate and independent assortment takes place

Question 31

what happens in anaphase 1?

Answer 31

spindle fibers pull homologous pairs apart | full haploid set of duplicated chromosomes at each pole of cell

Question 32

what happens in telophase 1?

Answer 32

spindle fibers degrade, chromosomes may or may not relax, new nuclear membrane may/may not form around chromosomes; cytokinesis happens

Question 33

what happens in meiosis 2?

Answer 33

very similar to meiosis 1, start with two haploid cell and form into four

Question 34

prophase 2?

Answer 34

2 cells form telophase 1 and condense and centrioles will duplicate, nuclear membrane breaks down and spindle fibers attach ***two chromosomes aren't identicle due to crossing over**

Question 35

metaphase 2?

Answer 35

identical to mitosis

Question 36

anaphase 2?

Answer 36

sister chromatid are pulled apart

Question 37

telophase 2?

Answer 37

chromosomes decondense, new nuclear membrane formed, cytokinesis takes place resulting in four genetically distinct gametes

Question 38

sperm formation by meiosis 1 germ cell ----> 4 sperm cells

Answer 38

spermogenesis

Question 39

egg formation by meiosis 1 germ cell---> 1 functional egg cell and 3 polar bodies

Answer 39

oogenesis

Question 40

what are problems with meiosis?

Answer 40

not perfect nondisjunction trisomy monosomy

Question 41

failure of chromosomes to separate correctly (typically in meiosis 1 or meiosis 2)

Answer 41

nondisjunction

Question 42

3 copies of a chromosomes in a cell that should be diploid

Answer 42

monosomy

Question 43

monosomy and trisomy together=

Answer 43

aneuploidy

Question 44

incorrect number of chromosomes in a cell

Answer 44

aneuploidy

Question 45

only non lethal monosomy in humans

Answer 45

turner syndrome

Question 46

what are the physical diffrences in people with turner syndrome?

Answer 46

nonfunctional ovaries, short, low set ears, webbed neck, several diseases

Question 47

what is wrong with klienefelter syndrome?

Answer 47

male with female features, typically infertile, LD, risk of breast cancer

Question 48

what is the difference in XXX syndrome?

Answer 48

appear normal, typically taller, normal sexully, LD,

Question 49

XYY syndrome? "super male"

Answer 49

tall, LD

Question 50

trisomy 21 is also known as what?

Answer 50

downs