Mitosis & Meiosis

Question 1

Two types of cell division

Answer 1

• Mitosis
• Meiosis

Question 2

Cytokinesis

Answer 2

Cytoplasm divides into two distinct daughter cells

Question 3

Meiosis leads to:

Answer 3

• Production of gametes
• Daughter cells have 1/2 genetic material as parent cell

Question 4

Mitosis leads to:

Answer 4

• Production of all other cell types (somatic cells)
• Genetic material copied and divided equally
• Daughter cells genetically identical to parent

Question 5

Cell division

Answer 5

Replicate genetic material, divide genetic material evenly, form two daughter cells

Question 6

Single-celled organsims cell division results in _________

Answer 6

asexual reproduction

Question 7

Multicellular organsims cell division allows for _________

Answer 7

• growth
• repair
• asexual reproduction

Question 8

4 phases of the cell cycle:

Answer 8

• M phase
• G₁ phase of interphase
• S phase of interphase
• G₂ phase of interphase

Question 9

Gap phases allow the cell to

Answer 9

• Grow large enough
• synthesize enough organelles for daughter cells
• function

Question 10

G₁ Phase

Answer 10

4 unreplicated chromosomes

Question 11

S phase

Answer 11

DNA synthesis

Question 12

G₂ Phase

Answer 12

4 replicaed chromosomes consisting of 2 sister chromatids

Question 13

M phase

Answer 13

• Start of mitosis, replicated chromosomes condense
• Mitosis

Question 14

Prophase

Answer 14

• Chromosomes condense
• spindle apparatus begins to form

Question 15

Prometaphase

Answer 15

• Nuclear envelope breaks down
• Microtubules contact centromeres

Question 16

Metaphase

Answer 16

Chromosomes line up in middle of cell

Question 17

Anaphase

Answer 17

Sister cromatids separate into daughter chromosomes

Question 18

Telophase

Answer 18

The nuclear envelope reforms and chromosomes condense

Question 19

Cell division

Answer 19

Plasma membrane pinches in and two daughter cells form

Question 20

Chromosome

Answer 20

structure composed of a DNA molecule and associated proteins

Question 21

Chromatin

Answer 21

• The material that makes up eukaryotic chromosomes
• DNA molecule complexed w/ histone proteins

Question 22

Chromatid

Answer 22

One strand of a repliecated chromosome, w/ its associated proteins

Question 23

Sister chromatids

Answer 23

• 2 strands of a replicated chromosome
• Replicated chromosomes consiste of 2 sister chromatids
• When sister chromatids separate during miosis they become independent chromosomes

Question 24

Cytokinesis in plants

Answer 24

microtubules direct vesicles to center of spindle where they fuse to divide the cell in two

Question 25

Cytokinesis in animals

Answer 25

cleavage furrow

Question 26

Bacteria divide via \_\_\_\_\_\_\_\_\_

Answer 26

* Fission * similar to animal cytokinesis

Question 27

\_\_\_\_\_\_\_\_\_ is essentially eliminated in rapidly dividing cells

Answer 27

* G₁ phase * Ex. epithelial cells of intestines

Question 28

G₀ State

Answer 28

* Nondividing cells perminantly stuck in G₁ phase * Ex. nerve cells

Question 29

Mitosis-promoting factor (MPF)

Answer 29

* Present in cytoplasm of M-phase cells * Induces mitosis in all eukaryotes

Question 30

MPF composed of:

Answer 30

* Protein kinase * Cyclin

Question 31

Protein kinase

Answer 31

Enzyme that catalyzes transfer of a phosphate group from ATP to target protein

Question 32

Cyclin

Answer 32

regulatory protein

Question 33

How is MPF turned off

Answer 33

Enzyme complex activated by mitosis degrades MPF cyclin during anaphase

Question 34

Negative feedback

Answer 34

Process slowed or stopped by one of its products

Question 35

Cell-cycle checkpoint

Answer 35

Interactions among regulatory moleculse at each checkpoint allow the cell to "decide" whether to procide with division

Question 36

If checkpoint regulatory molecules are defective:

Answer 36

* The checkpoint may fail * cells may start dividing in an uncontrolled fashion

Question 37

Pass G₁ Checkpoint If:

Answer 37

* Cell size is adequate * nutrients are sufficient * social signals are present * DNA is undamaged

Question 38

Pass G₂ Checkpoint if

Answer 38

* chromosomes have replicated successfully * DNA is undamaged * activated MPF is present

Question 39

Pass M-phase checkpoint if:

Answer 39

* Chromosomes attached to spindle apparatus * chromosomes have properly segregated and MPF is absent

Question 40

Cancer

Answer 40

Family of diseases caused by cells that: * Grow uncontrollably * invade nearby tissues * spread to other sites in the body

Question 41

Cancerous cell defects

Answer 41

* Make the proteins required for growth active when they shouldnt be * Prevent tumor suppressor genes from shutting down cell cycle

Question 42

Benign tumor

Answer 42

may continue to divide, but are not invasive

Question 43

malignant tumor

Answer 43

divide and spread to adjacent tissues through lymphatic/blood vessels

Question 44

Centromere

Answer 44

structure that joins sister chromatids

Question 45

kinetochores

Answer 45

structure on sister chromatids where microtubules attach

Question 46

microtubule organizing center

Answer 46

any structure that organizes microtubules

Question 47

Centrosome

Answer 47

microtubule organizing center in animals and some plants

Question 48

Centrioles

Answer 48

Cylindrical structures that comprise microtubules, located in centrosomes

Question 49

locus

Answer 49

position of a gene on a chromosome

Question 50

haploid number

Answer 50

number of distinct types of chromosomes

Question 51

ploidy

Answer 51

number of each type of chromosome present (n, 2n, etc)

Question 52

Meiosis I overview

Answer 52

* diploid parent cell produces 2 haploid daughter cells * homologs * separate to diff. daughter cells * daughter cells are haploid * chromosomes consist of 2 sister chromatids

Question 53

crossing over

Answer 53

Swapping of segments between maternal and paternal chromosomes

Question 54

Chiasma

Answer 54

Point at which crossing over occurs

Question 55

Independent assortment

Answer 55

random assortment/segregation of chromosomes during anaphase resulting in genetically unique gametes

Question 56

tetrad

Answer 56

pair of homologous chromosomes in synapsis

Question 57

Autosome

Answer 57

anything that isn't a sex chromosome