Cell Cycle, Mitosis, & Meiosis (Biology Summative)

Question 1

What is telomere?

Answer 1

The tip of a chromosome

Question 2

Oogenesis

Answer 2

Production of female gametes (ova)
Starts during fetal development

Question 3

Cell Division vs Nuclear Division

What is mitosis?

Answer 3

The division of the nucleus of the cell into two new nuclei

Question 4

Explain

What happens in Synthesis (S) stage?

Answer 4

Replication of DNA

Question 5

These are the cell’s control systems.
From these, the cell cycle stops until a go-ahead signal is received.

Answer 5

Checkpoints
* G1 Checkpoint (G1 to S)
* G2 Checkpoint (G2 to M)
* Spindle or M Checkpoint (Meta to Ana)

Question 6

Explain

What happens in Gap 1 (G1)?

Answer 6

The cell just finished dividing, so in Gap 1, it is recovering from mitosis

Question 7

Meiosis II

Telophase II and Cytokinesis II

Answer 7

• The cells split in half
• Four non-identical haploid daughter cells are produced from one original diploid cell

Question 8

Meiosis II

Anaphase

Answer 8

• Centromeres split
• Sister chromatids are pulled to the poles

Question 9

Meiosis I

Prometaphase

Answer 9

• Spindle fibers starting to attach to the chromosomes through its centromeres
• The chromosomes continue to condense

Question 10

What are diploids?

Answer 10

• two sets of chromosomes (2n)
• In humans, 23 pairs or 46 chromosomes in total

Question 11

• In this checkpoint, the DNA is examined for errors
• If errors are detected, the cell attempts to complete replication or repair damaged DNA in this checkpoint
• If the damage is irrepairable, the cell may undergo through apoptosis (cell suicide) to avoid replication of damaged DNA

Answer 11

G2 Checkpoint

Question 12

What happens in Gap 2 (G2)?

Answer 12

• Preparation for Mitosis
• Organelles are replicated
• More growth occurs

Question 13

Why does the activity of cyclin-dependent kinases fluctuate during the cell cycle?

Answer 13

Because they are controlled by cyclins, so named because their concentrations vary with the cell cycle.

Question 14

Difference of Mitosis and Meiosis

Answer 14

• Meiosis produces n while mitosis produces 2n
• Daughter cells produced through mitosis are genetically identical, opposite to meiosis
• In meiosis, division occurs twice but replication only once

Question 15

Meiosis II

Telophase II and Cytokinesis II

Answer 15

• The cells split in half
• Four non-identical haploid daughter cells are produced from one original diploid cell

Question 16

What is synapsis?

Answer 16

pairing of homologous chromosomes forming a tetrad (4 homologous chromatids or 2 homologous chromosomes)

Question 17

Cell Division vs Nuclear Division

What is cytokinesis?

Answer 17

The actual division of cells into two new cells

Question 18

This checkpoint checks if all the sister chromatids are correctly attached to the spindle microtubules

Answer 18

M Checkpoint (Spindle Checkpoint)

Question 19

What is haploid?

Answer 19

• One set of chromosomes (n)
• Gametes or sex cells
• In humans, 23 chromosomes

Question 20

Mitosis

What happens in metaphase?

Answer 20

• Chromosomes are pulled to the center of the cell
• They line up along the “metaphase plate”

Question 21

What does G1 checkpoint check before giving a go-signal?

Answer 21

• Cell size (is the cell large enough to divide?)
• Nutrients (Does the cell have enough energy reserves or available nutrients to divide?)
• Molecular signals (Is the cell receiving positive cues (such as growth factors) from neighbors?)
• DNA integrity (Is any of the DNA damaged?)

Question 22

Why do cells divide?

Answer 22

For reproduction, growth and repair of damaged cells

Question 23

Identify

Sequence of phases in the life cycle of a cell

Answer 23

Cell Cycle

Question 24

What causes variation?

Answer 24

• Crossing over in Prophase I
• Independent Assortment in Meta I and II
• Random Fertilization

Question 25

# Meiosis I Prophase I

Answer 25

* Chromosomes condense * Homologous chromosomes pair with each other * Each pair contains four sister chromatids (tetrad)

Question 26

Difference between cytokinesis in Plant and Animal cells

Answer 26

Animals: pinching of plasma membrane Plants: The cell elongates and the cell plate forms (future cell wall and cell membrane)

Question 27

* The checkpoint wherein the cell decided whether or not to divide * Once passed through, it becomes irreversibly committed to division

Answer 27

G1 Checkpoint

Question 28

Homologous Pair

Answer 28

* each chromosome in the pair are identical (carrying genes for same trait) * only one pair differs; sex chromosomes (x or y)

Question 29

What is centromere?

Answer 29

The point where sister chromatids are joined together

Question 30

Crossing Over

Answer 30

chromatids of tetrad exchange parts

Question 31

What is meiosis?

Answer 31

* Nuclear division that produces four daughter cells with half the number of chromosomes of parent cell * Important in sexual reproduction * Involves combining genes of parents to produce a genetically distinct individual

Question 32

# Meiosis I Telephase I and Cytokinesis I

Answer 32

* Daughter nuclei formed (haploid n)

Question 33

The two types of regulatory proteins that are involved in cell cycle control

Answer 33

Cyclins and Cyclin-dependent Kinases (Cdks)

Question 34

# Mitosis What happens in Prophase?

Answer 34

* Chromosome condenses * Microtubules form * The nuclear envelope breaks down

Question 35

What are the different periods under interphase and mitotic phase?

Answer 35

**Interphase** * Growth (G1) * Synthesis (S) * Growth (G2) **Mitotic Phase** * Mitosis * Cytokinesis

Question 36

# Meiosis II Prophase II

Answer 36

Spindle fibers form again

Question 37

# Mitosis What happens in Anaphase?

Answer 37

* Centromeres divide * Spindle fibers pull one set of chromosomes to each pole * Precise alignment is critical to division

Question 38

Spermatocytogenesis vs Spermiogenesis vs Spermatogenesis

Answer 38

Spermatocytogenesis: Process of producing 4 spermatids (Meiosis I + Meiosis II) Spermiogenesis: Converting spermatids to spermatozoa Spermatogenesis: Spermatocyto + Spermio; starts at puberty

Question 39

# Mitosis What happens in telophase?

Answer 39

* Nuclear envelope forms around chromosomes * Chromosomes uncoil * Cytokinesis

Question 40

What is mitosis?

Answer 40

A type of cell division in which a mother cell divides to produce two new daughter cells that are genetically identical to itself. In the context of cell cycle, it is the part of the division process in which the DNA of the cell's nucleus is split into two equal sets of chromosomes.

Question 41

# True or False Cells sometimes undergo mitosis without going through cytokinesis

Answer 41

True

Question 42

# Meiosis I Metaphase I

Answer 42

* Tetrads or homologous chromosomes move to the center of the cell * Independent assortment occurs

Question 43

# Meiosis I Anaphase I

Answer 43

Homologous chromosomes are pulled to opposite poles

Question 44

What is chiasmata?

Answer 44

The point of intersection during crossing over

Question 45

# True or False DNA is replicated for the second time in Meiosis II

Answer 45

False. No replication occurs during Meiosis II

Question 46

A cyclin-cdk complex that triggers a cell's passage past the G2 checkpoint into the M phase.

Answer 46

MPF (maturation-promoting factor)

Question 47

What are sister chromatids?

Answer 47

Identical structures that result from chromosome replication, formed during S phase

Question 48

# Mitosis What happens in Prometaphase?

Answer 48

* Nuclear envelope breaks down * Chromosomes attach to the mitotic spindle

Question 49

What does G2 checkpoint check before giving a go-signal?

Answer 49

* DNA integrity (Is any of the DNA damaged?) * DNA replication (Was the DNA completely copied during S phase?)

Question 50

# Meiosis II Metaphase II

Answer 50

Sister chromatids move to the center

Question 51

What is chromatin?

Answer 51

Thin, fibrous form of DNA and proteins