Meiosis Flashcards

Questions and Answers

When does Interphase occur?

before meiosis

What occurs during Interphase?

the cell does normal cell activities

What is uncoiled stringy DNA called?

chromatin

How many pieces of chromatin do human cells have?

46 Signup and view all the answers

Where does your DNA come from? (Select all that apply)

mother Signup and view all the answers

DNA has _____ that determine the trait of an organism.

genes Signup and view all the answers

Different forms of a gene are called _____.

alleles Signup and view all the answers

_ is when DNA copies itself during _.

Replication; Interphase Signup and view all the answers

What are made during Meiosis? List examples.

gametes, sex cells, sperm and eggs Signup and view all the answers

Meiosis occurs in ___ divisions; Meiosis _ and Meiosis ___.

two; I; II Signup and view all the answers

What are the phases of Meiosis I?

Prophase I, Metaphase I, Anaphase I, Telophase I Signup and view all the answers

What are the phases of Meiosis II?

Prophase II, Metaphase II, Anaphase II, Telophase II Signup and view all the answers

During Prophase I, the chromosomes _ and become _.

condense; visible Signup and view all the answers

Chromosomes that are the same size and have the same genes are called _ _.

homologous chromosomes Signup and view all the answers

Each half of a replicated chromosome is called a _ _.

sister chromatid Signup and view all the answers

Sister chromatids are _____.

identical Signup and view all the answers

The nucleus _____ during Prophase.

disintegrates Signup and view all the answers

Homologous chromosomes pair up during Prophase I to form a _____.

tetrad Signup and view all the answers

What happens during crossing over?

homologous chromosomes exchange genetic information Signup and view all the answers

During Metaphase I, the tetrads line up in the _____ of the cell.

middle (equator) Signup and view all the answers

The homologous chromosomes split up and move toward the opposite ends of the cell during _____.

Anaphase I Signup and view all the answers

_ independent cells begin to form during _.

Two; Telophase I Signup and view all the answers

_____ is the division of the cytoplasm to make two new cells.

Cytokinesis Signup and view all the answers

The two new cells that are formed from Meiosis I are _____ because they contain half of the chromosomes of the original cell that started Meiosis.

haploid Signup and view all the answers

At the start of Meiosis I, you had 1 _____ cell.

diploid Signup and view all the answers

Meiosis II must take place because each of our new cells still has too much _____.

DNA Signup and view all the answers

The nucleus _____ during Prophase II.

goes away Signup and view all the answers

In Metaphase II, the chromosomes line up single file down the _____ of the cell.

middle Signup and view all the answers

In _____, the sister chromatids split up.

Anaphase II Signup and view all the answers

In Telophase II, ___ _ daughter cells called ___ are being formed.

four; haploid gametes Signup and view all the answers

Each newly formed cell will form a _____ around the chromosomes.

new nucleus Signup and view all the answers

The chromosomes _ to form _.

uncoil; chromatin Signup and view all the answers

_____ occurs at the same time as Telophase II.

Cytokinesis Signup and view all the answers

At the end of Meiosis II, you have made _ _ gametes (sex cells).

four haploid Signup and view all the answers

If the gametes are produced by a female, they are called? (Select all that apply)

eggs Signup and view all the answers

If the gametes are produced by a male, they are called _____.

sperm Signup and view all the answers

What process in cells undergoing Meiosis increases genetic diversity?

crossing over Signup and view all the answers

How many cells are produced by Meiosis?

4 nonidentical haploid gametes Signup and view all the answers

How many varieties of gametes are produced by meiosis without crossing over?

2 Signup and view all the answers

What do you call two genes that are often inherited together?

they are linked Signup and view all the answers

What exchanged DNA during crossing over?

homologous chromosomes Signup and view all the answers

How many cells are produced by Meiosis in cells that do crossing over?

4; two sets of two that are identical Signup and view all the answers

How many varieties of gametes are produced by Meiosis with crossing over?

4; 4 nonidentical haploid gametes Signup and view all the answers

What is another term for the chromosomes that result from crossing over?

recombinant Signup and view all the answers

Does crossing over occur for every chromosome every time gametes are produced?

False Signup and view all the answers

When does Independent Assortment occur?

Metaphase I, Metaphase II Signup and view all the answers

The way each chromosome lines up during Metaphase I is _____.

random Signup and view all the answers

The alignment of the top pair of chromosomes will affect the alignment of the bottom pair.

False Signup and view all the answers

How many different combinations are possible in the first part of Meiosis because of Independent Assortment?

4 Signup and view all the answers

What separates during Anaphase II?

sister chromatids Signup and view all the answers

How does Independent Assortment affect genetic diversity?

sister chromatids of individual chromosomes line up randomly, resulting in a variety of possible genetic combinations in gametes Signup and view all the answers

What are the two types of gametes?

sperm, egg (ova) Signup and view all the answers

What process occurs when the sperm and egg combine?

fertilization Signup and view all the answers

For human beings, there are ___ of possible sperm and _ of possible eggs which can be produced resulting in ___ of possible genetic combinations.

millions; millions; trillions Signup and view all the answers

A genetic cross that looks at two traits is a _____ cross.

dihybrid Signup and view all the answers

What goes inside the boxes of a Punnet Square?

16 Signup and view all the answers

How many gene combinations are possible in gamete production for a dihybrid cross? Why?

8; from the FOIL process, each parent has 4 for a combination of 8 Signup and view all the answers

What is the term for a fertilized egg?

zygote Signup and view all the answers

Study Notes

Interphase and Chromatin

Interphase occurs before meiosis, during which the cell performs normal activities.
Chromatin refers to uncoiled, stringy DNA, and human cells contain 46 pieces of chromatin.

Genetic Inheritance

DNA is inherited half from the mother and half from the father.
Genes are segments of DNA that determine traits.
Different forms of a gene are called alleles.

Meiosis Overview

Meiosis involves two divisions: Meiosis I and Meiosis II, producing gametes (sperm and eggs).
The phases of Meiosis I include Prophase I, Metaphase I, Anaphase I, and Telophase I.
The phases of Meiosis II are Prophase II, Metaphase II, Anaphase II, and Telophase II.

Chromosome Behavior

During Prophase I, chromosomes condense and become visible, pairing as homologous chromosomes to form tetrads.
Crossing over occurs when homologous chromosomes exchange genetic information, enhancing genetic diversity.
Sister chromatids, identical halves of a replicated chromosome, separate during Anaphase II.

Cell Division and Resulting Cells

Cytokinesis, the cytoplasm's division, occurs during Telophase I and is essential for creating two new cells.
At the end of Meiosis I, two haploid cells are formed; these have half the chromosome number of the original diploid cell.
Meiosis II further divides these cells, resulting in four haploid gametes.

Genetic Variability

Four gametes are produced, and if crossing over occurs, they are nonidentical.
Independent assortment occurs during Metaphase I and Metaphase II, allowing random distribution of chromosomes, contributing to genetic diversity.

Fertilization and Genetic Combinations

Each sperm and egg produced results in trillions of possible genetic combinations after fertilization.
The term for a fertilized egg is zygote, which marks the beginning of a new organism's development.

Punnett Squares and Dihybrid Crosses

A dihybrid cross examines two traits and can yield 16 possible combinations in a Punnett square.
In gamete production for a dihybrid cross, there are 8 combinations possible due to the FOIL method, reflecting the genetic diversity possible from two traits.

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Description

Test your knowledge on meiosis with these flashcards. Each card covers essential concepts, such as interphase and the structure of DNA. Perfect for biology students looking to reinforce their understanding of cellular processes.