Meiosis Phases Flashcards

Questions and Answers

What is meiosis?

Is the process of mitosis.

Creates 2 diploid cells from a diploid cell.

Creates 4 haploid gamete cells from a diploid cell. (correct)

Involves nuclear membrane dissolution.

What happens during interphase in meiosis?

The DNA is in its chromatin form and the DNA replicates.

Describe prophase I in meiosis.

The DNA coils into visible chromosomes, sister chromatids are connected by a centromere, and crossing over occurs.

What does crossing over involve?

Homologous chromosomes join and share genetic information. Signup and view all the answers

What are homologous chromosomes?

Matching chromosomes from mother and father. Signup and view all the answers

What occurs during metaphase I?

Spindle fibers attach to centromeres and chromosomes line up in the middle. Signup and view all the answers

What happens during anaphase I?

Spindle fibers pull homologous chromosomes toward opposite poles. Signup and view all the answers

What is the outcome of telophase I?

Nuclear membranes start to form, and two diploid cells are created. Signup and view all the answers

What process occurs during cytokinesis?

The cytoplasm divides, resulting in two separate cells. Signup and view all the answers

What happens during prophase II?

Chromosomes reorganize, nuclear membranes dissolve, and spindles reform. Signup and view all the answers

Describe metaphase II.

Spindles are fully formed and chromosomes line up at the spindle's equator. Signup and view all the answers

What occurs during anaphase II?

Sister chromatids are pulled apart towards opposite poles. Signup and view all the answers

What is the result of telophase II?

Four haploid cells are produced. Signup and view all the answers

Define chromatin.

Thread-like structures containing all genetic information. Signup and view all the answers

Study Notes

Meiosis Overview

Meiosis produces four haploid gametes from one diploid cell, essential for sexual reproduction.

Interphase (Stage 1)

DNA exists in chromatin form and undergoes replication, preparing for the meiotic process.

Prophase I (Stage 2)

DNA coils into visible chromosomes; sister chromatids are linked by a centromere.
Nuclear membrane begins to dissolve; centrosomes move to poles and spindle fibers form.
Crossing over occurs, allowing genetic material exchange between homologous chromosomes.

Crossing Over

A process where homologous chromosomes pair up and exchange genetic information, enhancing genetic diversity.

Homologous Chromosomes

Chromosomes from each parent that match in size and shape, contributing to genetic variation.

Metaphase I (Stage 3)

Fully formed spindle fibers attach to centromeres of homologous chromosomes.
Chromosomes align at the cell's equatorial plane alongside their homologous partners.

Anaphase I (Stage 4)

Spindle fibers pull homologous chromosomes toward opposite poles, leading to chromosome separation.

Telophase I (Stage 5)

Chromosomes reach poles and nuclear membranes reform around each set, initiating de-coiling into chromatin.
Cytokinesis divides the cell, resulting in two diploid cells, which will undergo further division.

Cytokinesis

Division of the cytoplasm occurs during Telophase I and II, concluding each meiotic division phase.

Prophase II (Stage 6)

No interphase occurs between Meiosis I and II; chromosomes reorganize and nuclear membranes dissolve.
Sister chromatids are again connected by centromeres as spindles reform.

Metaphase II (Stage 7)

Spindle fibers attach to centromeres of the chromosomes, which realign in a single row along the spindle's equator.

Anaphase II (Stage 8)

Spindle fibers pull sister chromatids apart, moving each to opposite poles of the cell.

Telophase II (Stage 9)

Nuclear membranes form around each chromosome set; cleavage furrows develop.
Resulting in four haploid cells: in males, four functional sperm; in females, one viable egg and three polar bodies, which are generally non-functional.

Chromatin

Thread-like structures containing genetic information, visible only during Interphase, crucial for genetic material organization and replication.

Description

Explore the key phases of meiosis with these flashcards. Each card presents essential terms and definitions related to the process of meiosis, including interphase and prophase I. Perfect for high school biology students aiming to enhance their understanding of gamete formation.