"Heredity and Evolution" PPT

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"Heredity and Evolution" PPT

Part One: Heredity and Variation

1. Heredity: Organisms produce offspring through reproduction. The traits of offspring are very similar to their parents, and between offspring and offspring.

Let’s talk about it:

Are you more like your father or your mother? How are they more similar?

Are you exactly like them?

2. Variation: There are always certain differences in the characteristics of different biological individuals, the phenomenon of differences in characteristics between the offspring of organisms and their parents and between different individuals of the offspring.

Conclusion: Heredity and variation are ubiquitous life phenomena.

3. What is the significance of biological inheritance and variation to living things?

Heredity - Stabilizes the race of organisms.

Variation is the internal driving force for biological development and evolution.

Heredity and Evolution PPT, Part 2: Transmission of Genetic Material:

Let’s explore together:

Why do organisms exhibit similar genetic phenomena between parent and offspring? Where does genetic material reside? How is it transmitted?

In the 17th century, some scholars believed that human sperm or eggs contained the epitome of parental traits, so that the offspring developed from fertilized eggs possessed the genetic traits of both parents.

1. Genetic material:

(1)Chromosome:

Chromosomes are mainly composed of two substances: protein and deoxyribonucleic acid (DNA). DNA plays a decisive role in biological traits and is the main genetic material.

Chromosomes are located in the nucleus of the cell. During cell division, the most obvious phenomenon is the replication of chromosomes.

(2) DNA: plays a decisive role in biological traits and is the main genetic material.

In 1962, Crick and Watson were awarded the Nobel Prize in Physiology or Medicine for their discovery of the double helix structure of the DNA molecule and their contribution to uncovering the secrets of biological genetic information.

⑶ Gene: (genetic unit) is a segment of the DNA molecule that plays a genetic role. Each trait of an organism is controlled by a specific gene.

There are hundreds or thousands of genes on a DNA molecule, and each gene controls one or more traits (such as human skin color, color vision, flower shape, etc.).

The genetic composition in the cells of different individuals of the same species is different, so each person's traits are different.

Genetics and Evolution PPT, Part 3 Content: Knowledge Feedback:

1. Among the following relationships between chromosomes, DNA, and genes, which one is correct ( )

2. The characteristics of various organisms are determined by ( )

A. Determined by chromosomes B. Determined by proteins

C. Determined by genes D. Determined by cells

Keywords: Free download of science PPT courseware for the second volume of the ninth grade of the Zhejiang Education Edition, download of the genetic and evolution PPT, .PPT format;

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"Heredity and Evolution" PPT courseware:

"Heredity and Evolution" PPT courseware Part 1: Review before class: Where is the genetic material of organisms? What? Chromosomes are the carriers of genetic material. Genes are fragments of DNA that play a genetic role. DNA is genetic material. Genes determine the characteristics of organisms: genetic...

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Update Time: 2024-06-30

This template belongs to science courseware Zhejiang Education Edition Ninth Grade Science Volume 2 industry PPT template

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