"Causes of Biological Evolution" Biological Evolution PPT Courseware 6

Description

"Causes of Biological Evolution" Biological Evolution PPT Courseware 6

Knowledge review

Based on the general process of animal and plant evolution, summarize the overall trend of biological evolution.

In the long process of biological evolution, why do some biological species become extinct? How do new biological species arise? What drives biological evolution?

ANALYSE information

Based on the case of industrial blackening by birch inchworm, the group discussed and exchanged the following issues:

(1) What significance does the emergence of the black birch looper have on the survival of future generations?

(2) The number of black birch inchworms gradually changes from a minority to a majority. What is the main influence?

(3) Could you please try to analyze the reasons for the changes in body color of the birch inchworm? What are you inspired by?

1. Analyze the causes of biological evolution

Heredity and variation underlie body color changes in Betula geometrid

Changes in the environment are the external driving force for its body color changes

animal protective color

The body color of an animal is very similar to the color of its surrounding environment. This body color is called protective color.

New knowledge exploration

[Exploration Experiment] Simulate the formation process of protective color

1. Ask a question: How is the protective color formed?

2. Make assumptions. The formation of biological protective colors is related to the environment.

3. Make a plan

Kind tips

1. Each team member is in a group of five, and all team members follow the command of the team leader.

2. The color of the colored paper must be single, and each group can choose a different color; the colors should be diverse, but one of them should be consistent with the color of the colored paper.

3. When doing experiments, you must imagine yourself as a "predator". When selecting small pieces of colored paper, do not observe the position of the small pieces of paper in advance, and do not specifically look for small pieces of paper of a certain color.

4． The number of small pieces of paper should be recorded in time and analyzed.

5. Analyze and explore the discussion questions that follow.

express and communicate

1. In the first and fifth generations, which color of small pieces of paper has the most "survivors"? What does this have to do with the color of the colored paper?

2. What are the changes between the first generation and the second generation? What changes have occurred between the first and fifth generations?

3. Comparing the first and fifth generation "survivors", which color is not represented in the "survivor" group? Why?

4. Through the above simulation experiment, can you speculate on the formation process of protective color? Can you analyze the causes of biological evolution from this?

Class summary

1. The basis of biological evolution: inheritance and mutation

2. External driving force of biological evolution: changes in environment

3. Organisms can survive and reproduce only by adapting to the changing environment.

scientist story

Read "The Story of Scientists" on pages 72-73 of the textbook and think about the following questions:

1. What is the masterpiece that Darwin spent his whole life writing? What views on evolution does he propose in this book?

2. What inspirations have you received from studying Darwin’s short stories?

Read pages 70-71 of the textbook and discuss and exchange the following questions in groups:

1. How do you understand that living things generally have a strong ability to reproduce?

2. The reproductive ability of living things is so powerful, but in fact only very few of the offspring of each living thing survive. What is the reason?

3. The fundamental cause of biological variation is changes in environmental conditions. Some mutations are heritable and some are not. But which variations can be inherited?

4. Try to summarize Darwin’s theory of natural selection.

artificial selection

Definition: The process in which people form new biological varieties through continuous selection and cultivation according to their own needs and hobbies.

Application: 1. The domestication of wolves and the formation of different dog breeds. 2. The cultivation of corn and the formation of different varieties.

think

Based on what you learned earlier, how do you understand natural selection?

Creatures in nature go through a fierce struggle for survival. Those who adapt survive and those who do not adapt are eliminated. This is natural selection.

Living things continue to evolve through inheritance, mutation and natural selection.

Consolidation exercises

1. Generally speaking, ________ is non-directional, while ________ is directional. When an organism mutates, _______ determines its survival or elimination.

2. If you use an antibiotic for a long time, you will find that the effectiveness of the antibiotic becomes worse and worse. The reason is[

A. The result of directional mutation

B． The result of generation-by-generation selection of pathogenic bacteria by antibiotics

C. The result of generation-by-generation selection of antibiotics by pathogenic bacteria

D. genetic result

3. An incorrect understanding of Darwin’s theory of natural selection is[ ]

A. Choice is non-directional

B． Mutation is generally non-directional

C. Heritable variation is the basis of biological evolution

D. After long-term natural selection and accumulation, beneficial mutations of organisms may produce new types of organisms.

4. A certain drug for treating colds has a high efficacy, but its efficacy gradually decreases after a few years. The fundamental reason is ( )

A. After the virus comes into contact with the drug, it gradually develops resistance to the drug.

B. The virus has developed drug resistance in order to adapt to the environment.

C. Drugs are targeted for selection of drug-resistant mutations in viruses.

D. Later, the dosage of the drug was reduced, resulting in drug-resistant mutations.

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For more information about the PPT courseware "Evolution of Organisms and Reasons for Evolution of Organisms", please click the Evolution of Organisms ppt Reasons for Evolution of Organisms ppt tag.

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Update Time: 2024-09-25

This template belongs to biology courseware People's Education Edition Biology for Grade 8, Volume 2 industry PPT template

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