Ch.8

Question 0

Sexual reproduction

Answer 0

• ‼️Involves fertilization of an egg by a sperm.
• Involves two parent cells, each parent gives some of its characteristics to the offspring.
• Offsprings are genetically different from the parent.
• Type of cell division involved is called MEIOSIS.

Question 1

Asexual reproduction

Answer 1

• Offspring arise from a single parent cell.
• Daughter cells are genetic replicas of parent cell.
• ‼️No fertilization of egg by a sperm.
• Eg. Bacteria, Amoebas, sea star.
• The type of cell division process involved is called MITOSIS.
• Mitosis is also involved in regeneration.

Question 2

Chromosome

Answer 2

Has chromatin, chromatids and centromeres and DNA.

Question 3

Chromatin

Answer 3

is a combination of DNA and proteins that makes up the chromosome and helps in packaging DNA into a smaller volume to fit inside the cell and are important in cell division.

Question 4

Chromatids

Answer 4

What

Question 5

Centromere

Answer 5

The region of a chromosome where two sister chromatids are joined and where spindle micro tubes attach during mitosis and meiosis. The centromere divides at the onset of anaphase.

Question 6

Cell cycle stages

Answer 6

G1
S
G2
Mitosis

Question 7

G1

Answer 7

Cell cycle stage 1

Cellular contents, excluding the chromosomes, are duplicated

Question 8

S

Answer 8

Cell cycle stage 2

Each of the 46 chromosomes is duplicated by the cell

Question 9

G2

Answer 9

Cell cycle stage 3

The cell “double checks” the duplicated chromosomes for error making any needed repairs

Question 10

Mitosis

Answer 10

Cell cycle stage 4

• Nucleus and the chromosomes divide and are evenly distributed to form two daughter nuclei.
• Followed by CYTOKINESIS where the cytoplasm divides and forms two identical daughter cells.

Question 11

Mitosis stages

Answer 11

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 12

Prophase

Answer 12

•Chromosomes coil up.
•Duplicates chromosomes pair and crossing over occurs.
•Crossing over can give rise to genetic recombination.
•Spindle forms from the centrosomes.
(1)

Question 13

Metaphase

Answer 13

•Pairs of homologous chromosomes align in the middle of the cell.
•Spindle fibers from one pole attach to one homologous chromosome and the spindle fiber from the opposite pole attach to the other chromosome.
(2)

Question 14

Anaphase

Answer 14

•The pairs of homologous chromosomes are separated from each other and move towards the opposite ends of the cell.
(3)

Question 20

Telaphase

Answer 20

•Chromosomes arrive at the poles of the cell.
•Cytokinesis (division of the cytoplasm) occurs and two Haploid cells are formed.
(4)