Meiosis and Sexual Reproduction: Key Concepts and Processes in Genetics

What is the primary purpose of sexual reproduction?

To combine genetic information from two parents, resulting in genetically diverse offspring.

What are gametes?

Cells that carry genetic information from each parent for sexual reproduction.

How do diploid and haploid cells differ?

Diploid cells have two sets of chromosomes (2n), while haploid cells have one set (n).

What is the main difference between mitosis and meiosis?

Mitosis produces two identical diploid cells, while meiosis produces four genetically distinct haploid gametes.

What occurs during Meiosis I?

Homologous chromosomes are separated, resulting in two haploid cells.

What is crossing over and when does it occur?

Crossing over is the exchange of genetic material between homologous chromosomes, occurring during Prophase I.

How does independent assortment contribute to genetic diversity?

It randomly arranges chromosomes during Metaphase I, leading to various combinations in gametes.

What is the outcome of Meiosis II?

Separation of sister chromatids, resulting in four haploid gametes.

What is the significance of genetic diversity in offspring?

It enhances adaptability to environmental changes and reduces the risk of genetic diseases.

What is the role of fertilization in sexual reproduction?

It fuses two haploid gametes to form a diploid zygote, initiating development.

What is a tetrad?

A structure formed during Prophase I consisting of a pair of homologous chromosomes, each with two sister chromatids.

What happens during Anaphase I of meiosis?

Homologous chromosomes are pulled to opposite poles of the cell.

What is the difference in the number of cells produced by mitosis and meiosis?

Mitosis produces 2 diploid cells, while meiosis produces 4 haploid cells.

What is the purpose of cytokinesis in meiosis?

To divide the cytoplasm and organelles between the new cells after nuclear division.

What is the role of spindle fibers during meiosis?

To attach to chromosomes and help separate them during cell division.

How many chromosomes do human gametes contain?

Human gametes contain 23 chromosomes.

What is the probability of a specific chromosome combination occurring in offspring?

There is a one in 70 trillion chance of a specific combination occurring.

What is the significance of the sickle cell allele in relation to malaria?

It provides protection against malaria, making it more common in malaria-prone regions.

What is asexual reproduction?

A process where offspring are produced from a single parent, resulting in genetic clones.

What organisms typically use asexual reproduction?

Bacteria, some fungi, plants, and certain animals.

What occurs during Prophase II of meiosis?

A new set of spindle fibers forms to separate sister chromatids.

What is the outcome of telophase II and cytokinesis in meiosis?

Formation of four haploid gametes, each with a unique genetic composition.

What is the function of the nuclear envelope during meiosis?

It breaks down to allow spindle fibers to access chromosomes during division.

What is the significance of random alignment during Metaphase I?

It increases genetic variation by allowing different combinations of chromosomes to be segregated into gametes.

What is the main goal of Meiosis I?

To separate duplicated homologous chromosomes.

What is the primary source of genetic diversity in gametes?

Meiosis I, particularly through crossing over and independent assortment.

How does meiosis contribute to evolution?

By generating genetic diversity that can enhance survival and adaptation in changing environments.

What happens to the chromosome number during fertilization?

The haploid gametes fuse to restore the diploid chromosome number in the zygote.