more cell divison

Question 1

What happens during anaphase I of meiosis?

Answer 1

Homologous chromosomes are pulled to opposite poles, reducing the chromosome number by half.

Question 2

What happens during anaphase II of meiosis?

Answer 2

Sister chromatids are separated, similar to what occurs during mitosis.

Question 3

What is the key difference in alignment during metaphase in mitosis vs. meiosis I?

Answer 3

• Mitosis: Individual chromosomes align at the metaphase plate.
• Meiosis I: Homologous chromosomes align in pairs at the metaphase

Question 4

What is the function of meiosis in reproduction?

Answer 4

To produce gametes (sperm and eggs) with half the chromosome number, ensuring stability of the species’ chromosome count across generations.

Question 5

What key events during meiosis increase genetic variability?

Answer 5

1. Crossing over during prophase I.
2. Independent assortment of homologous chromosomes during

Question 6

During which phase does DNA replication occur?

Answer 6

S phase of interphase

Question 7

What structures are present in animal cells but not in plant cells during mitosis?

Answer 7

Centrioles

Question 8

What is nondisjunction, and when can it occur?

Answer 8

Nondisjunction is the failure of chromosomes to separate properly, occurring in either anaphase I or anaphase II of meiosis.

Question 9

What is parthenogenesis?

Answer 9

A type of asexual reproduction where an unfertilized egg develops into an organism, as seen in green aphids.

Question 10

What is budding?

Answer 10

An asexual process where a new organism grows as a bud from the parent, common in yeast.

Question 11

What is the dominant phase in a pine tree’s life cycle?

Answer 11

The diploid sporophyte phase.

Question 12

What is interkinesis, and what happens during it?

Answer 12

A resting phase between meiosis I and meiosis II where no DNA replication occurs.

Question 13

What is fragmentation, and give an example?

Answer 13

• A form of asexual reproduction where an organism breaks into pieces, and each fragment grows into a new organism.
• Example: Starfish or garden plants from cuttings.

Question 14

What is vegetative reproduction, and give examples?

Answer 14

• A process in plants where new individuals arise from specialized structures like runners, tubers, or rhizomes.
• Examples: Strawberries (runners) and potatoes (tubers).

Question 15

What is spore formation, and in which organisms does it occur?

Answer 15

Spore formation involves producing reproductive cells (spores) that can grow into a new organism without fertilization. Example: fungi, mosses, and ferns.

Question 16

What is alternation of generations?

Answer 16

A life cycle involving the alternation between a haploid gametophyte stage and a diploid sporophyte stage.

Question 17

What is a gametophyte?

Answer 17

The haploid stage in a plant’s life cycle that produces gametes (sperm and eggs) through mitosis.

Question 18

What is a sporophyte?

Answer 18

The diploid stage in a plant’s life cycle that produces haploid spores through meiosis.

Question 19

Which stage is dominant in mosses?

Answer 19

The gametophyte stage is dominant in mosses, with the sporophyte dependent on it.

Question 20

Which stage is dominant in ferns and seed plants?

Answer 20

The sporophyte stage is dominant in ferns and seed plants

Question 21

What role do spores play in alternation of generations?

Answer 21

Spores are produced by the diploid sporophyte through meiosis and grow into haploid gametophytes

Question 22

How do ferns reproduce in the alternation of generations?

Answer 22

1. The diploid sporophyte produces haploid spores.
2. The spores grow into a haploid gametophyte.
3. The gametophyte produces gametes, which fuse during fertilization to form a diploid zygote, developing into a new sporophyte.

Question 23

What is the significance of alternation of generations?

Answer 23

It promotes genetic diversity through meiosis and fertilization, adapting organisms to different environmental conditions.