Sexual Reproduction and Meiosis

Flashcards covering key concepts related to sexual reproduction and the process of meiosis.

Meiosis

A process that distributes genetic information into gametes and contributes to genetic diversity.

Germ cells

Diploid cells that undergo meiosis to produce haploid gametes.

Haploid

A cell that contains one complete set of chromosomes.

Zygote

A diploid cell formed by the fusion of two haploid gametes.

Mitosis

A process of cell division that results in two identical daughter cells, not involving genetic reduction.

Synapsis

The tight association between homologous chromosome pairs during Meiosis I.

Crossing over

The exchange of DNA segments between homologous chromosomes during Meiosis I.

Chiasmata

The sites of crossover events where homologous chromosomes are held together.

Metaphase I

Stage in Meiosis I where homologous chromosomes line up at the metaphase plate.

Independent assortment

The random orientation of chromosome pairs during metaphase that leads to genetic variation.

Reduction division

Another term for Meiosis I, as it reduces the chromosome number in daughter cells.

Aneuploid gametes

Gametes with an abnormal number of chromosomes, often resulting from nondisjunction.

Nondisjunction

The failure of chromosomes to separate properly during Meiosis I or Meiosis II.

Diploid

A cell that contains two complete sets of chromosomes.

Tetrad

A pair of homologous chromosomes consisting of four chromatids; formed during synapsis.

Microtubule spindle

The structure that helps segregate chromosomes during cell division, utilized in both meiosis and mitosis.

Meiosis

A process that distributes genetic information into gametes and contributes to genetic diversity.

Germ cells

Diploid cells that undergo meiosis to produce haploid gametes.

Haploid

A cell that contains one complete set of chromosomes.

Zygote

A diploid cell formed by the fusion of two haploid gametes.

Mitosis

A process of cell division that results in two identical daughter cells, not involving genetic reduction.

Synapsis

The tight association between homologous chromosome pairs during Meiosis I.

Crossing over

The exchange of DNA segments between homologous chromosomes during Meiosis I.

Chiasmata

The sites of crossover events where homologous chromosomes are held together.

Metaphase I

Stage in Meiosis I where homologous chromosomes line up at the metaphase plate.

Independent assortment

The random orientation of chromosome pairs during metaphase that leads to genetic variation.

Reduction division

Another term for Meiosis I, as it reduces the chromosome number in daughter cells.

Aneuploid gametes

Gametes with an abnormal number of chromosomes, often resulting from nondisjunction.

Nondisjunction

The failure of chromosomes to separate properly during Meiosis I or Meiosis II.

Diploid

A cell that contains two complete sets of chromosomes.

Tetrad

A pair of homologous chromosomes consisting of four chromatids; formed during synapsis.

Microtubule spindle

The structure that helps segregate chromosomes during cell division, utilized in both meiosis and mitosis.

What is the ultimate outcome of meiosis regarding cell number, ploidy, and genetic makeup?

Meiosis results in four genetically unique haploid sex cells (gametes) from a single diploid parent cell.

What is a key difference between mitosis and meiosis concerning the ploidy of daughter cells?

Mitosis produces diploid daughter cells, whereas meiosis produces haploid daughter cells.

Which two processes during meiosis are crucial for genetic variation among offspring?

Independent assortment of homologous chromosomes during Metaphase I and crossing over between homologous chromosomes during Prophase I.

Why is Meiosis I often referred to as 'reduction division'?

Because it reduces the number of chromosome sets from diploid (2n) to haploid (n) by separating homologous chromosomes.

What is the typical consequence of nondisjunction during meiosis?

It leads to the formation of aneuploid gametes, which have an abnormal number of chromosomes.