"Cells Proliferate through Division" PPT courseware

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"Cells Proliferate through Division" PPT courseware

Part One: Import

Do elephants with huge bodies have more cells in their bodies than mice with smaller bodies? Or are the cells too large?

Discussion: Why do cells need to stay smaller?

Explore Why are cells so small?

discuss

1. When the volume of a cube increases, how does the ratio of surface area to volume change?

Answer: As the volume increases, the ratio becomes smaller.

2. What is the relationship between cell size and material exchange with the outside world?

Answer: The smaller the cell, the larger its surface area, and the larger the area for the cell to exchange materials with the outside world.

Cells proliferate through division PPT, Part 2: Thoughts and Summary

Why can't cells grow indefinitely?

Answer: If cells grow indefinitely, the surface area of ​​larger cells will be relatively reduced, and the cell membrane will not be able to ensure that it obtains sufficient living substances from the external environment. The surface area of ​​smaller cells will be relatively larger, making it easier for the cells to exchange materials with the outside world, thus Ensure normal life activities of cells.

Division of animal and plant cells

When a plant cell divides, when the cell nucleus divides into two new nuclei, a new cell membrane is formed in the center of the cytoplasm between the two new nuclei and a new cell wall is produced, thus causing one plant cell to divide into two new cells.

When an animal cell divides, one nucleus first splits into two nuclei; then, the cell membrane in the center of the cell gradually dents inward from all sides, and finally the cytoplasm is divided into two, with each part of the cytoplasm containing a nucleus. Such a cell divides into two new cells.

process of nuclear division

During cell division, the genetic material in the nucleus is copied, doubled in quantity, and evenly distributed between the two new cells, thus ensuring that the new cell has the same genetic material as the parent cell.

Cells proliferate through division PPT, Part 3: What is the significance of cell division?

Take a look and think about it, what does cell division mean to an organism?

1. Cell division of single-celled organisms

2. Cell division in multicellular organisms

The significance of cell division to living organisms:

Single-celled organisms reproduce through cell division. Cell division of multi-cellular organisms is not only related to the reproduction of new individuals, but also promotes new individuals to grow from small to small, allowing the organism to continuously renew aging and dead cells, thus ensuring the normal life activities of the organism. .

discuss

How does genetic material change during cell division? What is the significance of this change?

Answer: During cell division, the genetic material in the nucleus is copied, doubled in quantity, and evenly distributed into two new cells. This ensures that the new cell has the same genetic material as the parent cell.

Cells proliferate through division PPT, Part 4 content: Summary: Cells proliferate through division

1. Why is the cell volume so small?

The surface area of ​​smaller cells is relatively large, which makes it easy for the cells to exchange materials with the outside world, thus ensuring the normal life activities of the cells.

2. Cell division produces new cells

1. When an animal cell divides, one nucleus first splits into two nuclei; then, the cell membrane in the center of the cell gradually dents inward from all sides, and finally the cytoplasm is divided into two parts, each part of the cytoplasm containing a nucleus. Such a cell divides into two new cells.

2. When a plant cell divides, when the cell nucleus divides into two new nuclei, a new cell membrane is formed in the center of the cytoplasm between the two new nuclei and a new cell wall is produced, thus causing one plant cell to divide into two new cells. .

3. The characteristics of cell division are: equal distribution of genetic material.

4. Single-cell organisms reproduce through cell division. Cell division of multi-cell organisms is not only related to the reproduction of new individuals, but also promotes new individuals to grow from small to small, allowing the organism to continuously renew aging and dead cells, thus ensuring the normality of the organism. Life Events.

Cells proliferate through division PPT, Part 5 content: Assignment:

1. Multiple choice questions:

1. The order of plant cell division is ( )

①The cytoplasm is divided into two parts, each part contains a new nucleus

②The cell nucleus divides into two new nuclei

③New cell membrane and cell wall are formed in the center of the mother cell

Ａ.①②③ Ｂ.②①③

C.③②① D.①③②

2. A cell of an organism contains X chromosomes. During cell division, the number of chromosomes changes: ( )

Ａ.X→X→X Ｂ.X→2X→2X

C.X→2X→X D.2X→2X→X

2. Short answer questions:

1. Give an example of the significance of human cell division.

2. Fill out the activity report on "Studying the Relationship between Cell Volume and Surface Area".

3. Please read the "Little Information" on page 54 after class. And consider whether cell division is beneficial to all organisms?

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

For more information about the "Cells Proliferate Through Division" PPT courseware, please click on the Cell PPT Cells Proliferate Through Division PPT tag.

"Cells Proliferate through Division" PPT:

"Cells Proliferate Through Division" PPT Part One Content: 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. Focusing on cell research in the prevention and treatment of cancer, etc..

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Update Time: 2024-07-03

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

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