Ch 8: Cell Reproduction

Question 1

Terms:

Cell division, cell cycle, cyclin, Cdk, \

Answer 1

Cell division: new cells originate from other living cells.
cell cycle : dividing cell stages
Cyclin : a regulatory subunit
CdK : a subunit with kinase activity that transfers phosphate groups from ATP to specific serine and threonine residues

Question 2

checkpoint, maturation promoting factor (MPF), mitotic spindle

Answer 2

Checkpoints — which are mechanisms that halt the progress of the cell cycle
Maturation-promoting factor（MPF）- a protein initiate entry of a cell into M phase
Mitotic spindle : reassembly of a complex，microtubule-containing “machine”

Question 3

Kinetochore, centrosome

Answer 3

Kinetochore : At the outer surface of the centromere of each chromatid，there are button-like structure，made of protein (assembles on the centromere during prophase)
Centrosome : special microtubule-organizing structure

Question 4

synapsis, recombination nodule,

Answer 4

Synapsis : process of chromosome pairing ( ช่วง meiosis prophase I)
Recombination : nodule electron-densed body indicating the sites where cross-over is taking placec ontain the enzymatic machinery that facilitates genetic recombination (the end of pachytene)

Question 5

bivalent/tetrad, chiasma.

Answer 5

Bivalent / tetrad a pair of synapsed homologous chromosomes

Chiasma are located at sites on the chromosomes where crossing-over between non-sister chromatids had occurred

Question 6

What are the four structural levels of chromatin?

Answer 6

Nucleosomes, solenoid, looped domain, and chromosome

Question 7

What are the two major phases the cell cycle can be divided into based on cellular activities readily visible with a light microscope?

Answer 7

M phase and interphase

Question 8

What are the three stages an interphase includes?

Answer 8

G1,S,G2

Question 9

What are the two processes an M phase includes?

Answer 9

mitosis, cytokinesis

Question 10

During which phase of mitosis, mitotic spindles are initiated assembling?

Answer 10

prophase

Question 11

In which phase of mitosis, all chromosomes align at the spindle equator?

Answer 11

metaphase

Question 12

What’s the function of Synaptonemal complex (SC) ?

Answer 12

(a scaffold to allow interacting chromatids to complete their crossover activities in meiosis)

Question 13

What kind of chromosomes are separated in the first and second meiotic division, respectively?

Answer 13

homologous chromosomes; sister chromatids

Question 14

Which factor plays a key role in driving eukaryotic cells from one stage to the next with its successive waves of synthesis and degradation in mitosis?

Answer 14

cyclins

Question 15

What are the five stages the meiosis prophase I includes?

Answer 15

leptotene, zygotene, pachytene, diplotene, diakinesis

Question 16

During the development of vetebrate oocytes, at which stages are they arrested prior to birth and right before ovulation?

Answer 16

prophase I, metaphase II