Meiosis And Life Cycles

Question 1

What is the main purpose of sexual reproduction?

Answer 1

Produces genetic variation, essential for evolution and adaptation to environmental changes

Genetic variation allows populations to adapt to changing environments, enhancing survival.

Question 2

What process generates genetic diversity?

Answer 2

Meiosis

Meiosis is a specialized form of cell division that leads to the formation of gametes.

Question 3

What type of cells are produced by meiosis?

Answer 3

Haploid gametes (egg and sperm)

Each haploid gamete contains one copy of every chromosome.

Question 4

How does meiosis contribute to genetic variability?

Answer 4

By shuffling DNA

This shuffling occurs through processes such as crossing over and independent assortment.

Question 5

What is the outcome of mitosis?

Answer 5

Two genetically identical diploid cells

Mitosis is responsible for growth and restoration of somatic tissues.

Question 6

What is the outcome of meiosis?

Answer 6

Four genetically unique haploid cells

These cells are the result of two rounds of division.

Question 7

How many divisions occur in meiosis?

Answer 7

Two divisions (Meiosis I and Meiosis II)

Each division plays a crucial role in the formation of gametes.

Question 8

Do homologous chromosomes pair in mitosis?

Answer 8

No

In mitosis, there is no pairing of homologous chromosomes.

Question 9

What happens to homologous chromosomes during Meiosis I?

Answer 9

They pair, recombine, and separate

This process is essential for the generation of genetic diversity.

Question 10

What feature distinguishes meiosis from mitosis regarding genetic diversity?

Answer 10

Meiosis has high genetic diversity

This is due to crossing over, independent assortment, and random fertilization.

Question 11

Fill in the blank: The main purpose of mitosis is _______.

Answer 11

[Growth and restoration of somatic tissues]

Question 12

True or False: Meiosis results in genetically identical cells.

Answer 12

False

Meiosis produces genetically unique haploid cells.

Question 13

What occurs during Prophase I of Meiosis?

Answer 13

Homologous chromosomes pair (synapsis), forming tetrads and crossing over occurs at chiasmata.

Question 14

What is the result of Anaphase I in Meiosis?

Answer 14

Homologs separate, reducing chromosome number by half.

Question 15

What happens during Telophase I and Cytokinesis in Meiosis?

Answer 15

Two haploid cells are formed, each with one set of chromosomes.

Question 16

What is the first stage of Meiosis II?

Answer 16

Prophase II: Chromosomes condense again in haploid cells.

Question 17

In Meiosis II, what occurs during Metaphase II?

Answer 17

Sister chromatids align at the metaphase plate.

Question 18

What happens during Anaphase II of Meiosis?

Answer 18

Sister chromatids separate.

Question 19

What is produced at the end of Telophase II and Cytokinesis?

Answer 19

Four haploid gametes are produced.

Question 20

Fill in the blank: In Meiosis I, homologous chromosomes pair during _______.

Answer 20

Prophase I

Question 21

True or False: Meiosis II is similar to Mitosis.

Answer 21

True

Question 22

What is crossing over?

Answer 22

Homologous chromosomes exchange genetic material, creating new allele combinations.

This process occurs during Prophase I of meiosis.

Question 23

What is independent assortment?

Answer 23

Random orientation of homologous pairs at the metaphase plate results in 2^n possible combinations.

In humans, this leads to approximately 8.4 million combinations.

Question 24

What happens during independent assortment in Metaphase II?

Answer 24

Random orientation of sister chromatids at the metaphase plate results in 2^n possible combinations.

In humans, this results in over 70 trillion combinations.

Question 25

What is random fertilization?

Answer 25

Any sperm can fuse with any egg, further increasing genetic variability. ## Footnote This contributes significantly to the genetic diversity of offspring.

Question 26

Describe the life cycle of animals.

Answer 26

Gametic meiosis produces gametes directly, which fuse during fertilization to form a diploid zygote. ## Footnote This is a direct cycle from gametes to zygote.

Question 27

What is the alternation of generations in plants?

Answer 27

Sporic meiosis: Sporophyte (diploid) undergoes meiosis to produce four haploid spores instead of gametes. ## Footnote Spores grow into a gametophyte (haploid), which produces gametes via mitosis.

Question 28

What process do fungi and algae undergo for reproduction?

Answer 28

Zygotic meiosis. ## Footnote Upon fertilization, the zygote undergoes meiosis directly, producing spores instead of gametes.

Question 29

Fill in the blank: The random orientation of homologous pairs at the metaphase plate results in _______ possible combinations.

Answer 29

2^n

Question 30

True or False: Crossing over occurs during Metaphase II.

Answer 30

False ## Footnote Crossing over occurs during Prophase I.

Question 31

In the alternation of generations, the gametophyte is _______.

Answer 31

haploid

Question 32

What do spores germinate to form in fungi and algae?

Answer 32

Haploid organisms that undergo mitosis to make their gametes. ## Footnote Since they are already haploid, meiosis is not needed again.