GIZMOS Student Exploration| Meiosis Answer Key 100% COMPLETE SOLUTIONS DOWNLOAD TO SCORE OUTSTANDING GRADE A

interphase

Name: Date:November 6th 2020

Student Exploration: Meiosis

Vocabulary: anaphase, chromosome, crossover, cytokinesis, diploid, DNA, dominant, gamete,genotype,

germ cell, haploid, homologous chromosomes, interphase, meiosis, metaphase, mitosis, ovum,

phenotype, prophase, recessive, sister chromatid, sperm cell, telophase, zygote

Prior Knowledge Questions (Do these BEFORE using the Gizmo.)

1. During mitosis, a single cell divides to produce two daughter cells. What must happen inthe

original cell so that each of the daughter cells has a complete set of chromosomes?

The DNA must replicate

2. During sexual reproduction, two sex cells fuse to create a fertilized cell with a complete setof

chromosomes. What must be true about the number of chromosomes in each sex cell?

There must be 2 one x and one y or both X.

Gizmo Warm-up

Meiosis is a type of cell division that results in four daughter cells

with half as many chromosomes as the parent cell.

These daughter cells mature into gametes, or sex cells. In the

Meiosis Gizmo, you will learn the steps in meiosis and

experiment to produce customized sex cells and offspring.

On the STEPS tab, click Male. You are looking at a germ cell,

or a cell that will undergo meiosis to become gametes.

1. Read the description of at the bottom of the Gizmo. What happens to the cell at

the beginning of interphase? The cell grows in size and doubles its organelles.

2. Click on the DNA in the nucleus of the cell. Describe what happens. The DNA duplicatesand

allows the cell to continue to grow

3. Why is it necessary for the cell to grow and duplicate its DNA before the start of meiosis?

Because when a parent cell undergoes mitosis it divides into two daughter cells and they all

need DNA thats why before mitosis takes place there must be a duplicate of the DNA.

Activity A: Steps

in meiosis

Get the Gizmo ready:

 Make sure the STEPS tab is selected.

 If necessary, choose the Male cell. Click on the

DNA to copy it to proceed to prophase I.

Introduction: Unlike mitosis, which produces two identical daughter cells from one parent cell,meiosis

creates four unique daughter cells with half the amount of DNA as the parent cell.

Question: How does meiosis create four daughter cells from one parent cell?

1. Observe: (Prophase I) Click on the nucleus to break it down then click on the DNA to

condense it into chromosomes. Drag the centrosomes to the top and bottom of the cell.

A. How many chromosomes does this cell have? 2

Each chromosome consists of a pair of sister

chromatids, two identical strands of DNA that formed

when DNA replicated during interphase.

B. On the image to the right, draw two lines connectingthe

pairs of homologous chromosomes (chromosomes of

similar size with a matching set ofgenes).

In the Gizmo, drag the homologous chromosomes

together. Click Continue.

2. Observe: (Metaphase I and Anaphase I) - Drag the groups of homologous chromosomes tothe

metaphase plate, then drag spindle fibers from each of the centrosomes to the chromosomes. Click the

centrosome to pull the chromosomes apart.

How do the chromosomes separate in anaphase I? The centrosomes attach spindle fibers toeach mom

the chromosomes to pull them apart and to opposites sides of the cell.

3. Compare: An image of the anaphase step in mitosis is shownto the

right.

A. How does anaphase I in meiosis differ from anaphasein

mitosis? key difference between mitosis and meiosis is that

sister chromatids remain joined during

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