Biology_Week 7 - Cell Division

Front 1

Mitosis and cytokinesis occur in what kind of cells?

Back 1

Eukaryotes only

Front 2

Cell division of unicellular eukaryotes

Back 2

reporduction of the entire organism known as asexual reproduction

Front 3

Cell division of multicellular organisms roles

Back 3

1. Reproduction 2. Growth and development 3. Tissue renewal

Front 4

Cell cycle

Back 4

the life of a cell from the time it is forst formed from a dividing parent cell until its own division into two daughter cells

Front 5

When a cell divides what does each daughter cell need?

Back 5

Whole set of genetic material. DNA.

Front 6

What is genetic material?

Back 6

Genes

Front 7

What is genetic material organized into?

Back 7

Chromosomes, every species has specific #

Front 8

What is a set of DNA?

Back 8

One of each type of chromosome, called genome

Front 9

What is the minimum number of sets of chromosomes?

Back 9

One

Front 10

Can an organism have more than one set?

Back 10

Yes, complex organisms like humans have two sets

Front 11

Chromosome

Back 11

Molecule of DNA that is associated with proteins, made of chromatin

Front 12

Chromosomes uncondensed

Back 12

chromosomes exist as long stringy loosely coiled uncondensed chromatin

Front 13

Requirements for Cell Division

Back 13

1) replicaiton of DNA 2) condensation of chromosomes 3) distribution of DNA to daughter cells

Front 14

Requirements for Cell Division: Replication of DNA

Back 14

replicated while chromatin is still stringy, uncondensed

Front 15

Requirements for Cell Division: Chromosomes Condense

Back 15

Duplicated chromosomes condenses into tightly packaged chromosomes like balls of yarn

Front 16

Requirements for Cell Division: Distribution of DNA

Back 16

sister chromatids unglue; one copy of east DNA molecule is distrubuted to each 2 daughter cells; daughter cells are genetically IDENTICAL to each other

Front 17

Sister Chromatids

Back 17

Identical duplicated DNA strands

Front 18

Mitosis

Back 18

division of the DNA (chromosomes) and the nucleus

Front 19

Cytokinesis

Back 19

division of the rest of the cell into two cells

Front 20

In what state is DNA when it is replicated?

Back 20

Uncondensed

Front 21

How many chromosomes is a sister chromatid?

Back 21

1 chromosome

Front 22

What are the two phases of the cell cycle?

Back 22

Interphase, Mitotic Phase

Front 23

Phases of the Cell Cycle: Interphase

Back 23

Normal cell state, replication of chomosomes in preparation for division

Front 24

Phases of the Cell Cycle: Mitotic

Back 24

Mitosis, Cytokinesis

Front 25

In what phase of the cell cycle is DNA synthesized?

Back 25

Interphase: S

Front 26

Mitosis: Prophase

Back 26

pro=first; splindle is forming, chromosomes condense

Front 27

Mitosis: Prometaphase

Back 27

nuclear membrane splits up, form sister pairs, beginning to attach to spindle

Front 28

Mitosis: Metaphase

Back 28

form in the middle of the spindle on metaphase plate

Front 29

Mitosis: Anaphase

Back 29

sister chromatids are seperated

Front 30

Mitosis: Telophase

Back 30

cell cleavage, genetically identical daughter nuclei form at opposite ends of the cell

Front 31

What usually begins during late telophase?

Back 31

Cytokinesis

Front 32

What is the name of the temporary cytoskeletal structures that attach to chromosomes during mitosis?

Back 32

Mitotic spindle

Front 33

What is the structure that gives rise to the mitotic spindle? In what species is it found?

Back 33

Centrosomes (and centrioles), animal

Front 34

What is the mitotic spindle made of?

Back 34

microtubules

Front 35

Where does the assembly of the spindle microtubules begin?

Back 35

centrosome

Front 36

At what phase does centrosome and centrioles replicate?

Back 36

Interphase: S

Front 37

Are centrosomes found in plant cells?

Back 37

NO

Front 38

Centro-mere

Back 38

part, central part of sister chromatids

Front 39

Centro-some

Back 39

body, bigger part

Front 40

Centri-ole

Back 40

small, 2 of them

Front 41

To what do spindle microtubules attach on the centromere?

Back 41

Kinetochores

Front 42

What causes sister chromatids to align in the middle of the cell?

Back 42

Back and forth tugging by the microtubules

Front 43

What seperates sister chromatids?

Back 43

pulled apart by kinetochore microtubules

Front 44

How do microtubules shorten?

Back 44

depolymerizing at their kinetochore ends

Front 45

Chromatids are pulled apart with help form what?

Back 45

motor proteins walking chromosome to opposite side of cell

Front 46

Are all kinetochores attached to chromatids?

Back 46

No, they are called non-kinetochore microtubules and they contribute to expanding the cell into two parts

Front 47

What is the difference between cytokinesis in Animal v. Plant?

Back 47

cleavage furrow in animal cells, cell plate laid from vesicles in plant cells

Front 48

What is a contractile right of microfilaments called? Purpose?

Back 48

Cleavage furrow, seperates newly formed cells

Front 49

What regulates the cell cycle?

Back 49

Molecular control system

Front 50

Does it differ among eukaryotes?

Back 50

No

Front 51

What are check points?

Back 51

Allow cell to "check" whether it is ready to move on to next event

Front 52

Three major check points

Back 52

Start (g1), G2/M (G2), Metaphase-to-Anaphase (M)

Front 53

Three major check points: Start (G1)

Back 53

Is environment favorable?, proceed to S Phase

Front 54

Three major check points: G2/Mitosis (G2)

Back 54

Is all DNA Replicated? Is Environment Favorable?, proceed to Mitosis

Front 55

Three major check points: Metaphase-to-Anaphase (M)

Back 55

Are all chromosomes attached to spindle?, trigger anaphase and proceed to cytokinses

Front 56

What happens if no go-ahead?

Back 56

Non-dividing (G0) phase

Front 57

In what phase do cells that virtually never divide reside?

Back 57

G0, non-dividing stage, stem cells can save the day

Front 58

Do CDK levels change during the cell cycle? What changes?

Back 58

NO! Activity of the CDKs fluctuate.

Front 59

What determines CDK activity?

Back 59

Cyclin levels

Front 60

What do CDKs do specifically?

Back 60

phosphorylate proteins, CDK is a protein kinase

Front 61

What are two examples of internal checkpoint signals?

Back 61

DNA not properly replicated (G2), kinetochores not attached (M)

Front 62

What is an example of external checkpoint signals?

Back 62

Growth factors = proteins released by certain cells that stimulate other cells to grow

Front 63

What are two space related examples of external checkpoint signals?

Back 63

Density dependent inhibition, anchorage dependence

Front 64

Density dependent

Back 64

crowded cells stop dividing

Front 65

Anchorage dependence

Back 65

cells must be attached to a substratum in order to divide

Front 66

What is the definition of cancer?

Back 66

uncontrolled cell division, do not respond to normal mechanisms that control cell division