Which of the following correctly describes meiosis?

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

The Elements of Life

In biology, the elements of life are the essential building blocks that make up living things. They are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. The first four of these are the most important, as they are used to construct the molecules that are necessary to make up living cells. These elements form the basic building blocks of the major macromolecules of life, including carbohydrates, lipids, nucleic acids and proteins. Carbon is an important element for all living organisms, as it is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. Even the cell membranes are made of proteins. Carbon is also used to construct the energy-rich molecules adenosine triphosphate (ATP) and guanosine triphosphate (GTP). Hydrogen is used to construct the molecules water and organic compounds with carbon. Hydrogen is also used to construct ATP and GTP. Nitrogen is used to construct the basic building blocks of life, such as amino acids, nucleic acids, and proteins. It is also used to construct ATP and GTP. Oxygen is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. It is also used to construct ATP and GTP. Phosphorus is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids.

Continue Learning about Biology

What statements correctly describe meiosis?

The cells produced at the end of meiosis contain half the number of chromosomes as the parent cell

Which of the following options correctly describes the behavior of a tetrad during anaphase you of meiosis?

It separates into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.

Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis you and meiosis II?

DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

The failure of chromosomes to separate correctly during meiosis is known as what?

Nondisjunction

What correctly identifies Prophase I?

Prophase I is a stage in meiosis. The letter that correctly identifies Prophase I is the letter G, which corresponds to growth.

• During meiosis one cell divides twice to form four daughter cells.
• These four daughter cells only have half the number of chromosomes of the parent cell – they are haploid.
• Meiosis produces our sex cells or gametes (eggs in females and sperm in males).

Meiosis can be divided into nine stages. These are divided between the first time the cell divides (meiosis I) and the second time it divides (meiosis II):

Meiosis I

1. Interphase:

• The DNA in the cell is copied resulting in two identical full sets of chromosomes.
• Outside of the nucleus are two centrosomes, each containing a pair of centrioles, these structures are critical for the process of cell division.
• During interphase, microtubules extend from these centrosomes.

2. Prophase I:

• The copied chromosomes condense into X-shaped structures that can be easily seen under a microscope.
• Each chromosome is composed of two sister chromatids containing identical genetic information.
• The chromosomes pair up so that both copies of chromosome 1 are together, both copies of chromosome 2 are together, and so on.
• The pairs of chromosomes may then exchange bits of DNA in a process called recombination or crossing over.
• At the end of Prophase I the membrane around the nucleus in the cell dissolves away, releasing the chromosomes.
• The meiotic spindle, consisting of microtubules and other proteins, extends across the cell between the centrioles.

3. Metaphase I:

• The chromosome pairs line up next to each other along the centre (equator) of the cell.
• The centrioles are now at opposites poles of the cell with the meiotic spindles extending from them.
• The meiotic spindle fibres attach to one chromosome of each pair.

4. Anaphase I:

• The pair of chromosomes are then pulled apart by the meiotic spindle, which pulls one chromosome to one pole of the cell and the other chromosome to the opposite pole.
• In meiosis I the sister chromatids stay together. This is different to what happens in mitosis and meiosis II.

5. Telophase I and cytokinesis:

• The chromosomes complete their move to the opposite poles of the cell.
• At each pole of the cell a full set of chromosomes gather together.
• A membrane forms around each set of chromosomes to create two new nuclei.
• The single cell then pinches in the middle to form two separate daughter cells each containing a full set of chromosomes within a nucleus. This process is known as cytokinesis.

Meiosis II

6. Prophase II:

• Now there are two daughter cells, each with 23 chromosomes (23 pairs of chromatids).
• In each of the two daughter cells the chromosomes condense again into visible X-shaped structures that can be easily seen under a microscope.
• The membrane around the nucleus in each daughter cell dissolves away releasing the chromosomes.
• The centrioles duplicate.
• The meiotic spindle forms again.

7. Metaphase II:

• In each of the two daughter cells the chromosomes (pair of sister chromatids) line up end-to-end along the equator of the cell.
• The centrioles are now at opposites poles in each of the daughter cells.
• Meiotic spindle fibres at each pole of the cell attach to each of the sister chromatids.

8. Anaphase II:

• The sister chromatids are then pulled to opposite poles due to the action of the meiotic spindle.
• The separated chromatids are now individual chromosomes.

9. Telophase II and cytokinesis:

• The chromosomes complete their move to the opposite poles of the cell.
• At each pole of the cell a full set of chromosomes gather together.
• A membrane forms around each set of chromosomes to create two new cell nuclei.
• This is the last phase of meiosis, however cell division is not complete without another round of cytokinesis.
• Once cytokinesis is complete there are four granddaughter cells, each with half a set of chromosomes (haploid):
  • in males, these four cells are all sperm cells
  • in females, one of the cells is an egg cell while the other three are polar bodies (small cells that do not develop into eggs).

Illustration showing the nine stages of meiosis.
Image credit: Genome Research Limited

This page was last updated on 2021-07-21

What correctly describes meiosis?

Which of the following is true for meiosis?

What is meiosis definition quizlet?

What correctly describes mitosis?