Cell Division Lab Worksheet PDF

Preview

Summary

Cell Division Lab Worksheet from fall 2021...

Description

Name:

Instructor & Section:

Cell Division Worksheet Compare the nuclear and chromosomal activities in mitosis and meiosis by completing the following table. Use a combination of drawings and descriptions. (8 points) Table 1

Comparing Nuclear and Chromosomal Activities in Mitosis and Meiosis Activities

Mitosis

Meiosis

Synapsis

Does not occur because sister chromatids duplicate

The pairing of two homologous chromosomes to form a tetrad

Crossing Over

No crossing over because the chromatids duplicate the chromosomes line up down the center

The trading of genetic material in the homologous pair

In anaphase spindle fibers pull each other apart

Same as mitosis

When Centromeres Split

Anaphase I: Spindles pull homologous chromosomes to opposite poles

Chromosomes Structure and Movement During Anaphase

Number of Divisions

Number of Cells Resulting

Number of Chromosomes on Daughter Cells Genetic Similarity of Daughter Cells to Parent Cells

Spindles pull chromosomes apart, into two chromatids and they move to opposite poles

Anaphase II: Centromeres split as chromosomes are pulled apart into two chromatids, as spindles contracts they go to the opposite poles

The cell divides once, chromosomes divide once

Cell divides once, then turn into two daughter cells divide once

2

4

46

23

2 identical daughters

4 unique daughters

F21 1

Section 1: Observing Phases of Mitosis and Cytokinesis Complete Table 2: Using a pencil, draw all structures that characterize each phase of cell division, including nucleus, nuclear envelope, nucleolus, aster, centromere, chromatids, chromosomes, spindle fibers, centrioles, and cleavage furrow. All drawings should be clear, colored, and labeled. (10 points) Table 2

White Fish and Onion Root Cells at Various Stages of Mitotic Cells Division Phase of Cell Division

Prophase

Prometapha se

Metaphase

White Fish

Onion Root

Brief Description of Each Phase Chromatids condense and begin to form a visible chromosome in the nucleus. Centrioles start to move to the opposite ends of the walls, and asters turn into miotic spindles. The nucleolus is still present.

Nuclear envelope breaks down and the spindles start to attach to the the centromeres and the nucleolus vanishes

Chromosomes line the center of the cell, and spindle fibers attach the centromeres to the chromosomes and begin to pull them apart.

Hint: Notice the absence of the cell wall in the white fish slide as most cells appear as round or irregularly shaped. In addition, aster is an array of microtubules at the poles around which the microtubules of the spindle and asters appear to radiate.

White Fish and Onion Root Cells at Various Stages of Mitotic Cells Division continued Phase of Cell Division

White Fish

Anaphase

Telophase

Onion Root

Brief Description of Each Phase Spindles pull apart the chromosomes. They pull each chromatid to opposite ends of the cell where the poles are. The cleavage furrow begins to form

Spindles go back to aster formation, and the nuclear envelopes form again around the chromatids on opposite ends of the cell. Cleavage happens to prepare cell to split in two in animals or the cell wall forms in the middle of the nuclei to split the cell in plants

Hint: Notice the absence of the cell wall in the white fish slide as most cells appear as round or irregularly shaped. In addition, aster is an array of microtubules at the poles around which the microtubules of the spindle and asters appear to radiate.

Section 2: Modeling Interphase and Meiosis

Draw each step or utilize the photos taken to show a comprehensive figure displaying the steps of meiosis. If drawing, use colors and labels to identify chromosomes and crossing over. (8 points)

Name:

Cell Division Worksheet Review Questions 1. Describe any observations made regarding differences and similarities between plant (onion root) and animal (white fish) cells regarding each of the phases of mitosis. (2 points) At the end mitosis, in telophase, animal cells form a cleavage furrow so that they can separate. In plant cells a cell wall forms down the middle to split the cell into two. Plant and animal cells go through the same processes and phases and some actions are done to chromosomes/ chromatids

2. Explain how crossing over changed the structure of the sister chromatids in the new nuclei in meiosis I. (2 points)

The crossing over of sister chromatids changes the structure by swapping a piece of DNA between the chromatids in meiosis 1

3. Answer the following questions based on Section 2: Modeling Interphase and Meiosis (chromosome beads). (3 points) a. How many chromosomes were present per cell when the entire process began? _____46_____ b. Are the nuclei formed at the end of meiosis I haploid (n) or diploid (2n)? __haploid________ c. How many chromosomes are in each daughter cell at the end of meiotic cell division? ___23_______ d. How many daughter cells are formed at the end of meiosis II? ____4______ e. Are the nuclei formed at the end of meiosis II haploid (n) or diploid (2n)? ____haploid______ f.

How many of the cells formed by the meiotic division are genetically identical? __0 bc of crossing over________

4. Explain the results obtained in meiotic cell division in terms of independent assortment and crossing over. (2 points From meiotic cell division, after stages 1 and 2, haploid cells are formed, and they are all unique from each other through crossing over. Then, during interphase, the chromosomes randomly line up in the middle of the cell, making the assignment of the chromosomes completely random thus forcing them to assort independently....