Exam 3 first lecture

Question 1

What is the nature of eukaryotic DNA?

Answer 1

Linear chromosomes

Question 2

What do linear chromosomes contain?

Answer 2

Chromatin

Question 3

What is chromatin?

Answer 3

Folded complex of proteins + DNA

Question 4

How many chromosomes are in the human body?

Answer 4

46

Question 5

How many types of chromosomes are there?

Answer 5

23 (Type A-W)

Question 6

What do homologous chromosomes contain?

Answer 6

Same genes

Question 7

What are alleles?

Answer 7

Different versions of a gene

Question 8

What is a ploidy?

Answer 8

of sets of chromosomes in a nucleus

Question 9

How many sets of chromosomes does a diploid have? Haploid? Triploid? Tetraploid?

Answer 9

2; 1; 3; 4

Question 10

What is the Cell Cycle?

Answer 10

The generation of a cell to division of a cell

Question 11

What are the 3 stages in the Cell Cycle?

Answer 11

Interphase, Mitosis, Cytokinesis

Question 12

What is Mitosis?

Answer 12

The division of the nucleus

Question 13

What is Cytokinesis?

Answer 13

Cytoplasmic division

Question 14

What are the stages in interphase?

Answer 14

Gap (G1), Synthesis, Gap (G2)

Question 15

What is G1?

Answer 15

• growth
• normal cell stuff
• massive production of enzymes necessary for DNA replication

Question 16

What happens in Synythesis?

Answer 16

DNA replication

Question 17

What is a dyad?

Answer 17

A pair of sister chromatids

Question 18

What are sister chromatids?

Answer 18

Identical copies of chromosomes that are held together by a centromere.

Question 19

What does a centromere contain?

Answer 19

Kinetochore microtubules

Question 20

What specific thing replicates in synthesis? (MOTC)

Answer 20

Centriols

Question 21

What happens in G2?

Answer 21

• growth
• massive production of tubulin
• mitochandria/chloroplasts divide

Question 22

What is another word for Mitosis?

Answer 22

Nuclear Division

Question 23

What are the phases of Mitosis?

Answer 23

Prophase, Prometaphase, Metaphase, Anaphase, Telophase/Cytokinesis

Question 24

What occurs during Prophase?

Answer 24

• Chromosomes start condensing
• centriols move to opposite ends of the cell
• centriols produce polar microtubules and Aster microtubules

Question 25

What occurs during Prometaphase?

Answer 25

- nuclear envelope disappears - chromosomes finish condensing (tight and visible) - centriols produce kinetochore microtubules

Question 26

What is the Spindle Apparatus?

Answer 26

P microtubules, A microtubules, K microtubules

Question 27

What occurs during Metaphase?

Answer 27

- K microtubules move dyads to center of the cell (metophasis plate) and lines them up in a disc arrangment.

Question 28

What occurs during Anaphase?

Answer 28

- polar microtubules get longer - centromeres break - K microtubules get shorter, which pulls the chromatids to opposites ends of the cell.

Question 29

What occurs during Telophase/Cytokinesis?

Answer 29

- Chromatids reach opposite ends and get contained within nuclei - spindle apparatus disappers - chromatids decondense - Actin belt at metaphasis plate constricts, pinching the cell in half

Question 30

What is the area called when the cell is undergoing Cytokinesis?

Answer 30

Cleavage furrow

Question 31

Plant cells undergoing cell division is the same process as animal cells EXCEPT?

Answer 31

-no centriols in MOTC - no aster fibers - cytokinesis occurs through cell plate formation

Question 32

What is the specific process of cell division plant cells go through?

Answer 32

The golgi apparatus makes vesicles that line up in the middle of the cell. - vesicles combine - splits membrane to two separate cells - cells secrete their own cell walls

Question 33

What kind of division does Meosis do?

Answer 33

Reduction division

Question 34

What are the two divisions of Meosis?

Answer 34

Meosis I and II

Question 35

What are the stages of Meosis I?

Answer 35

Prophase I, Metaphase I, Anaphase I, Telophase/Cytokinesis I

Question 36

Describe Prophase I

Answer 36

- same as preparation in Mitosis - Synapsis occurs

Question 37

What is Synapsis?

Answer 37

Homologous chromosomes line up and H-bond to each other. Crossing over occurs now (Homologo exchange segment). It ends in two chromatids that have exchanged chromosomes.

Question 38

Describe Metaphase I

Answer 38

Tetrads line up at Metaphasis plate

Question 39

Describe Anaphase I

Answer 39

Homologs separate and dyad's get pulled to opposite ends of the cell

Question 40

Describe Telophase/Cytokinesis I

Answer 40

- same as Mitosis except: - the chromosomes stay condensed and the nuclear envelope does not form - Independent Assortment

Question 41

What is Independent Assortment?

Answer 41

Random arrangement of homologous pairs at the Metaphasis plate in Metaphase I - Parental sets of chromosomes do not stay together in the first Meiotic division.

Question 42

What is Meiosis II?

Answer 42

Mitosis of haploid cells

Question 43

What are the phases of Meiosis II?

Answer 43

Prophase II, Metaphase II, Anaphase II, Telophase/Cytokinesis II

Question 44

Describe Prophase II

Answer 44

spindle apparatus forms and centriols replicate

Question 45

Describe Metaphase II

Answer 45

- same as Mitosis. Humans have 23 dyads

Question 46

Describe Anaphase II

Answer 46

- same as Mitosis - humans: 23 on each side

Question 47

Describe Telophase/Cytokinesis II

Answer 47

Same as Mitosis