Meiosis Flashcards

Questions and Answers

What important event must take place during interphase before a cell proceeds to division?

DNA replication must take place during interphase before.

What two structures make up a single replicated chromosome?

Sister chromatids make up a single replicated chromosome.

How many replicated chromosomes does the cell contain during prophase?

The cell contains 4 replicated chromosomes during prophase.

At what stage in meiosis I do the pairs of homologous chromosomes come together?

During the end of prophase I. Signup and view all the answers

Once the chromosomes have formed a pair, what are they called?

Tetrads. Signup and view all the answers

At the end of meiosis I, two cells have been produced. How many chromosomes are in each of these cells?

There are two chromosomes in each of the two cells. Signup and view all the answers

At what stages of meiosis I are the cells diploid and at what stages are they haploid?

The cells are diploid during prophase, metaphase, and anaphase. Then in telophase, after the two cells divide and four cells form, they are haploid. Signup and view all the answers

Describe the relationship between the cells at the end of telophase I and the original cell.

The new cells have two copies of half of the genetic information in the original cell. Signup and view all the answers

Will the cells at the end of telophase I be genetically identical to each other?

False Signup and view all the answers

In meiosis I, during anaphase I, which structures separated—homologous chromosomes or sister chromatids?

The homologous chromosomes separated. Signup and view all the answers

During anaphase II, what structures separated: sister chromatids or homologous chromosomes?

The sister chromatids separated. Signup and view all the answers

At the end of meiosis II, are there four daughter cells that are haploid or diploid?

True Signup and view all the answers

Describe the relationship between the cells at the end of meiosis II and the original cell.

The new cells have one copy of half of the genetic information in the original cell. Signup and view all the answers

When does crossing over occur in meiosis?

Crossing over occurs during prophase I. Signup and view all the answers

When the chromosomes come together as homologous pairs, what are the crossover points called?

Chiasmata. Signup and view all the answers

Describe what happens to the chromatids during crossover.

The chromosomes will begin to line up with their homologous pairs and the parts of the homologous pair switch places on the chromatids. Signup and view all the answers

What phrase is used to describe the chromatids after crossing over takes place and the homologous chromosomes separate?

The phrase used is recombinant chromatids. Signup and view all the answers

Are the genes on a recombinant chromatid the same as the original chromatid?

True Signup and view all the answers

Are the alleles on a recombinant chromatid the same as the original chromatid?

False Signup and view all the answers

If there were three sets of homologous chromosomes in the cell, how many possible arrangements would there be for the tetrads in late prophase I?

8 arrangements are possible. Signup and view all the answers

Explain how meiotic events, as well as the random fertilization of eggs and sperm, together lead to genetic variation.

Random fertilization of the egg and sperm is caused when allele combinations on the chromosomes are randomized, leading to different gene combinations each time. Signup and view all the answers

Study Notes

Meiosis Overview

DNA replication occurs during interphase, essential before cell division.
A single replicated chromosome comprises two sister chromatids.

Chromosome Count in Meiosis

During prophase, a cell contains 4 replicated chromosomes.
At the end of meiosis I, each of the two resulting cells has 2 chromosomes.

Homologous Chromosomes and Meiosis Stages

Homologous chromosome pairs come together at the end of prophase I, forming tetrads.
Cells are diploid during prophase, metaphase, and anaphase, and shift to haploid after telophase I when two cells divide to form four.

Genetic Information Post-Meiosis

Cells at the end of telophase I contain half of the genetic information of the original cell, meaning they are not genetically identical due to different alleles on separated homologous pairs.
At the end of meiosis II, four daughter cells are haploid, each with one chromosome pair.

Crossing Over and Genetic Variation

Crossing over occurs during prophase I, allowing chromatids to exchange genetic material.
Crossover points where chromatids interact are known as chiasmata.
The resulting chromatids post-crossover are referred to as recombinant chromatids.

Alleles and Genes on Chromatids

Genes on recombinant chromatids remain the same as original chromatids but may possess different alleles due to the switch during crossover.
The likelihood of different arrangements during tetrad formation is significant, with 8 potential configurations for three sets of homologous chromosomes.

Role of Random Fertilization

Genetic variation is enhanced by random fertilization of eggs and sperm, influenced by the random assortment of alleles during meiosis.
Each zygote created through fertilization has a unique genetic makeup, underscoring the diversity in offspring.

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Description

Test your knowledge on key events of meiosis with this set of flashcards. Understand the processes that occur during interphase and the structure of replicated chromosomes. Perfect for students studying cell division.

Meiosis Flashcards - Part 2