Biology Lesson 7: Life Cycle of the Cell

Question 1

The cell life cycle is divided into two phases:

Answer 1

inter phase and the mitotic phase

Question 2

Interphase is where all–

Answer 2

normal cellular activities occur

Question 3

G1 phase

Answer 3

cell growth, ending when the cell reaches maturity
-increases in size
-makes new organelles
-synthesizes

Question 4

S phase

Answer 4

the period where DNA undergoes replication
-helicase breaks the case base pairs apart
-DNA polymerase attaches new bases resulting in a duplicate set of DNA
-microtubules are also replicated which will help separate the DNA during mitosis

Question 5

G2

Answer 5

continued period of growth and reorganization in preparation for mitosis

Question 6

Prophase:

Answer 6

-the duplicated DNA is packaged into chromosomes
-two identical halves of sister chromatides are bundled together into one chromosome and fastened together with a centromere
-microtubules form the mitotic spindle, which attaches to the chromosomes and directs their moments
-the cell begins to dismantle the nucleolus and the nuclear envelope disintegrates

Question 7

Metaphase:

Answer 7

-all the chromosomes line up in the middle of the cell
-chromosomes attach to the mitotic spindle by the centromeres
-the sister chromatids appear to be repelling one another which causes the chromosomes to form an x shape

Question 8

Anaphase:

Answer 8

-the sister chromatids are pulled away from each other
-enzymes break down the proteins in the centromere and the chromatides separate, at which point they’re called daughter chromosomes
-the daughter chromosomes are moved by the mitotic spindle to opposite ends of the cell
-the cell begins to constrict across the middle in order to split into two

Question 9

Telophase:

Answer 9

-telophase begins when the chromosomes reach the end of mitotic spindle
-a new nucleus begins to form around each set of daughter chromosomes forming two daughter nuclei
-chromosomes begin to uncoil back into their chromatin form
-the mitotic spindle is broken down
-when the nuclear arch brane has formed, mitosis is complete

Question 10

Organisms reproduce either through–

Answer 10

a sexual reproduction or sexual reproduction where two cells come together to form a new organism

Question 11

Gamete:

Answer 11

the two cells which come together to form a new organism

Question 12

Male gamete:

Answer 12

sperm cell

Question 13

Female gamete:

Answer 13

egg cell

Question 14

Gametes have–

Answer 14

half the number of chromosomes as other cells

Question 15

Meiosis:

Answer 15

a type of cell division that makes sexual reproduction possible

Question 16

Meiosis occurs through two cell divisions:

Answer 16

Meiosis 1, Meiosis 2

Question 17

Meiosis 1

Answer 17

1. Interphase
2. Prophase 1
3. metaphase 1
4. anaphase 1
5. telophase 1

Question 18

Meiosis

Answer 18

1. prophase 2
2. metaphase 2
3. anaphase 2
4. telophase 2