"Cells Proliferate through Division" PPT

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"Cells Proliferate through Division" PPT

Part One: Teaching Objectives

1. Describe the basic process of cell division; state the results of chromosome changes during cell division.

2. Explain the relationship between cell division and biological growth. Pay attention to the value of cell research in preventing and treating cancer.

wonderful natural phenomena

An ancient poem goes: "Sow a grain of millet in spring and harvest ten thousand grains in autumn." Do you know what kind of natural phenomenon this describes? Why do organisms grow from small to large? In this class, let's explore the mysteries together.

Cells proliferate through division PPT, part 2 content: exploration outline

1. Can you try to describe the process of cell division while drawing?

2. What is the most important change during cell division? What is the result of this change?

3. Can cells grow indefinitely? Why?

4. How do organisms grow?

5. Talk about your understanding of cancer cells

Why can organisms grow from small to large?

1 Cell growth (growth) - increase in cell volume

2 Cell division (division)—the increase in the number of cells

Cell division is the process by which one cell divides into two cells.

Cells proliferate through division PPT, Part 3: Cell division (chromosome changes)

Observe the changes in chromosomes during cell division. What are the rules for the changes in the number of chromosomes?

The shape and number of chromosomes in the two new cells are the same, and the shape and number of chromosomes in the new cell and the original cell are also the same.

The genetic material DNA of the new cell is the same as that of the original cell.

discuss

Before and after cell division, although the number of cells doubles, the chromosomes and genetic material of each cell do not increase or decrease. What is the significance of this?

Ensure that the cells that divide are the same as the original ones

plant cell division process

Steps of cell division:

1 First, the nucleus is divided into two,

After 2, the cytoplasm is divided into two

3 Finally, a new cell membrane is formed, and plant cells also form a new cell wall.

Cells proliferate through division PPT, Part 4: The impact of cell size on the entry and exit of materials

Ask the question: Does cell size have any effect on the movement of materials in and out?

Make an assumption: Cells that are too large are not conducive to the movement of materials in and out.

Make a plan: Experiment with simulated cells in agar mixed with phenolphthalein.

Implementation plan: Soak the agar block with sodium hydroxide and observe the coloring.

The conclusion is drawn: the larger the volume, the less likely it is for matter to enter the center.

Expression communication: Assuming that it is true, the cell volume cannot increase infinitely.

Cells proliferate through division PPT, Part 5: Cancer-causing factors in life include:

Chemical carcinogens (including pesticides and fertilizers), radiation, viruses, moldy and spoiled food, toxic gases, polluted water, etc. It is possible for normal cells to turn into cancer cells.

To prevent cancer, you should:

1. Don’t smoke and drink less.

2. Eat less pickled, grilled and high-fat foods.

3. Eat more whole grains, green vegetables and fruits.

4. Do not eat moldy or spoiled food.

5. Avoid excessive sun exposure and moderate exercise.

Cells proliferate through division PPT, Part 6: Practice

1. Fill in the blanks:

1. The process of dividing a cell into two cells is called ____________.

2. The growth of organisms is related to two factors:

(1) The increase in the number of cells in an organism - the result of ____________.

(2) The increase in cell volume of an organism - the result of ____________.

3. When a cell divides, ________ first divides from one into two. Then, ________ divides into two parts, each containing one ________. Finally, a new ________ is formed in the center of the original cell, and plant cells also form new ones. of________.

2. Multiple choice questions:

1. During cell division, the structures evenly distributed into the two cells are:

A. Cell membrane B. Cytoplasm C. Nucleus D. Chromosome

2. An organism grows from small to large as a result of _____.

A. Increase in cell volume B. Increase in number of cells

C. Cell division and cell growth D. Cell division or cell growth

3. The correct order of the following steps of cell division is:

①The cytoplasm is evenly divided into two parts ②The replicated chromosomes enter two new nuclei respectively ③A new cell membrane is formed

A, ①②③ B, ③②① C, ②①③ D, ②③①

4. There are 46 chromosomes in the human cell nucleus. After two cell divisions, four cells are formed. The number of chromosomes in each cell is:

A. 92 items B. 46 items C. 23 items D. Unsure

Keywords: Beijing Normal University version of seventh-grade biology PPT courseware for free download, cells proliferate through division PPT download, .PPT format;

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"Cells Proliferate through Division" PPT courseware:

"Cells Proliferate Through Division" PPT courseware Part 1: Introduction Compared with a large elephant and a small mouse, do elephants have more cells in their bodies? Or are the cells too large? Discussion: Why do cells need to stay smaller? Explore ..

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Update Time: 2024-11-23

This template belongs to biology courseware Beijing Normal University Edition Seventh Grade Biology Volume 1 industry PPT template

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