bio-.cell cycle/reproduction

Question 0

Chromatin

Answer 0

Loosely wound strands of DNA

Question 1

What is a chromosomes

Answer 1

A single strand of DNA condensed and wrapped around many histone proteins

Question 2

Chromatid (sister chromatids)

Answer 2

Half of a chromosome

Question 3

Centromere

Answer 3

Where sister chromatids are held together

Question 4

Chromosome

Answer 4

Duplicated chromatids (duplicated for cell division )

Question 5

Telomeres

Answer 5

Ends of chromosome

Question 6

Two types of chromosomes and how many of each

Answer 6

Autosomes - 44 (determine your traits)

Sex chromosomes - 2 (determine your sex)

Question 7

Homologous chromosomes

Answer 7

Two copies (one from each parent)
Carry genes for the same traits
Same size and shape

Question 8

Diploid cells

Answer 8

2n
Cells that have two sets of chromosomes
Somatic cells

Question 9

Haploid cells

Answer 9

n
Cells that only have one set of Chromosomes
Sex cells (sperm and egg only have 23)

Question 10

Why is mitosis/cell division necessary

Answer 10

Cell gets bigger, DNA doesn’t

Question 11

Asexual reproduction

Answer 11

Binary fission-cell growth and replication -plasme amembrwne grows inward and splits into two
In prokaryotic cells

Question 12

Steps of mitosis

Answer 12

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 13

Steps of interphase - describe each

Answer 13

G1 - growth and acquire nutrients
S - DNA synthesis occurs, replicate every chromosome
G2 - completion of growth and readying for division

Question 14

What and when are the three checkpoints

Answer 14

G1->S is DNA intact?
G2->M have you completed DNA replication?
Metaphase -> anaphase Are chromosomes aligned on metaphase plate?

Question 15

3 major events during prophase

Answer 15

1. Chromosomes condense
2. Spindle microtubules form
3. Chromosomes captured by spindle fibers

Question 16

Metaphase

Answer 16

Spindle fibers (attached to chromosomes) align chromosome On metaphase plate

Question 17

Anaphase

Answer 17

Sister chromatids are pulled apart and gather towards one pole, as spindle fibers begin to push cell apart

Question 18

4 events of Telophase

Answer 18

1. Spindle microtubules disintegrate
2. Nuclear membrane firms around group of chromosomes at poles
3. Chromosomes unwind into normal state
4. Nucleoli reappear

Question 19

Cytokinesis

Answer 19

Animal cells: microfilaments attach to membrane and form ring at equator and starts to pinch together

Plant cells : cell plate (with cell wall material) forms along equator of cell

Question 20

What can happen if growth isn’t controlled

Answer 20

Tumors, cancer

Question 21

Purpose of meiosis

Answer 21

Create haploid gametes that are genetically unique

Question 22

Meiosis I

Answer 22

Separates homologous chromosomes

Question 23

Meiosis II

Answer 23

Separates sister chromatids

Question 24

Phases of meiosis I and II

Answer 24

Same as mitosis but with I or II to distinguish

Question 25

When does crossing over occur

Answer 25

Prophase I

Question 26

What’s different between metaphase I and regular metaphase / metaphase II

Answer 26

The homologous chromosomes are “zipped together” by proteins to ensure that they stay together when aligning on the metaphase plate, so that they separate during t anaphase