Making Connections

Today in class we took some time to step back and think about how the topics we have covered in the units of Ecology, Biochemistry, Cell Structure, Cell Transport and Cell Communication all connect.  Students created diagrams in small groups discussing the connections between at least 3 topics from within 3 different units that we have covered.  We will continue trying to make these connections as new material is introduced. 

Tomorrow we are going to focus on cell division through mitosis and cytokinesis and the causes and impacts of cancer on cell division. 

Homework:  This is a pasted version of the word document I EMAILED TO YOU at 11:00 this morning!!
Several images are missing from below, so please consult the version in your email.

Name: ______________________________________________

Define the following terms:

Chromosome:

Somatic cell:

Gamete:

Mitotic spindle:

Centrosome:

Kinetochore:

12.1 Cell Division results in genetically identical daughter cells

1.  How many chromosomes are in each of your somatic cells?  _____  How many chromosomes are in each human gamete? ____

2.  You are going to have to learn the difference between a number of similar-sounding terms. The sketch that looks like an X represents a replicated chromosome that has two sister chromatids. The narrow “waist” represents the location of the centromere. Students often get all these terms confused, so take time now to label the indicated areas of the figure and then define each of the terms below.

chromosome

chromatid

centromere

chromatin

3. What is mitosis?  How is it different from cytokinesis?

4.  Select either mitosis or meiosis to answer the following questions.

___________________ By what process are the damaged cells in a wound replaced?

___________________ By what process are eggs formed?

___________________ By what process does a zygote develop into a multicellular organism?

___________________ In which process are identical daughter cells produced?

___________________ Which process reduces chromosome number of daughter cells?

5.  A hedgehog has 90 chromosomes in its somatic cells.

a. How many chromosomes did the hedgehog inherit from each parent? _____

b. How many chromosomes are in each of the hedgehog’s gametes? _____

c. How many chromosomes will be in each somatic cell of the hedgehog’s offspring? _____

12.2 The mitotic phase alternates with interphase in the cell cycle.

6.  Label each of the parts of the cell cycle listed below, and give a brief explanation of what happens in each phase.

G1
S
G2
M

7.  You will need to spend some serious time with Figure 12.6. Use it to help you label the figure below. (1)  Label each phase by name,   (2) label the structures in the picture, (3) make 2 or 3 summary statements that indicate important features to note about the phase.

Label	Phase	Important Features

8.  After reading through the section titled Mitotic Spindle (beginning on p. 221 and ending on 224) paraphrase how the mitotic spindle accomplishes the separation of chromosomes.

9.  Compare cytokinesis in a plant and an animal cell.

Only true of animal cell cytokinesis	True of both plant and animal cell cytokinesis	Only true of plant cell cytokinesis

10.  Summarize the process of binary fission.