"Sex and Gender Determination" PPT

Description

"Sex and Gender Determination" PPT

Part One: Review knowledge points

Trait expression depends on genetic makeup

Alleles are divided into dominant genes and recessive genes

Dominant and recessive genes determine dominant and recessive traits respectively

Dominant traits occur when dominant and recessive genes coexist

Genes are passed down from generation to generation with gametes

Pairs of genes separate from each other during gamete formation

Genes combine freely during gamete union

Genes are passed on to the next generation with the fusion of gametes

Gender and Gender Determination PPT, Part 2 Content: Knowledge Learning Objectives

(1) Tell how gender is determined.

(2) Briefly describe the principle of giving birth to a boy or a girl.

Reading and inquiry

1. How many pairs of chromosomes are there in human cells? What are they?

2. What are autosomes and sex chromosomes?

3. What determines a person’s gender?

4. What are the genotypes of male and female sex chromosomes?

5. What determines whether a boy or a girl is born? What is its probability?

Gender and gender determination PPT, part 3 content: Gender ratio imbalance:

1. According to the fifth national census data, the sex ratio of male to female babies born in Hainan Province is 135.64 per 100 babies, ranking the highest in the country.

2. Guangdong’s gender ratio is the second highest in the country at 130.30 to 100, which is seriously high.

3. The sex ratio at birth of men and women in our country continues to rise. Population experts predict that there will be 30 million bachelors in our country by 2020.

What are the consequences of an imbalanced sex ratio in the population?

The imbalanced sex ratio of babies at birth seriously hinders the harmonious, sustainable and healthy development of our country's population, and will greatly lead to illegal and criminal activities such as marriage-buying and trafficking in women, as well as various complex social problems.

Legal regulations:

The Ministry of Health has issued an emergency notice, strictly prohibiting the gender identification of fetuses, and stipulating severe penalties for illegal gender identification.

Gender and Gender Determination PPT, Part 4: Main knowledge points of this lesson

1. Sex is determined by chromosomes:

22 pairs of autosomes

1 pair of sex chromosomes

Male is XY

Female is XX

2. The birth of a boy or girl depends on the type of sperm:

Women can only produce one type of egg cell: 22+X

Men produce two types of sperm: 22+X or 22+Y

The number of the two types of sperm is basically equal, their vitality is roughly the same, and they have equal opportunities to combine with egg cells.

Gender and Gender Determination PPT, Part 5: Knowledge Competition

1. The birth of a boy or girl is completely decided by the mother.

2. Both men and women have 23 pairs of chromosomes in their somatic cells, and there are 23 pairs of chromosomes in their reproductive cells. Therefore, the chromosomes of men and women are exactly the same.

3. The 23rd pair of human chromosomes is called the sex chromosomes.

4. Men can produce two types of sperm containing X chromosomes and two types of sperm containing Y chromosomes at the same time; women only produce one type of egg cells containing X chromosomes.

5. Each pair of chromosomes in biological cells comes from the father and the mother, so biological offspring have the genetic material of both parents.

6. The gender of a newborn baby mainly depends on sperm and egg cells.

1. How many types of sperm are produced by men? ( )

A.1 species B.2 species C.23 species D.46 species

2. How many types of egg cells do women produce? ( )

A.1 species B.2 species C.23 species D.46 species

3. Human gender differences are mainly determined by ____________. There are 23 pairs of chromosomes in human body cells. Among them, 22 pairs of chromosomes that are not related to gender are called ____________________, and 1 pair of chromosomes that is related to sex determination is called __________.

4. A certain male classmate’s parents gave him _____ chromosomes through gametes. Among them, the sex chromosomes given to him by his father are _____ chromosomes, and the sex chromosomes given to him by his mother are _____ chromosomes.

Keywords: Beijing Normal University version of the eighth grade biology PPT courseware for the first volume is free to download, gender and gender determination PPT download, .PPT format;

For more information about the PPT courseware "Heredity and Variation of Organisms, Sex and Sex Determination", please click the "Inheritance and Variation of Organisms, PPT Sex and Gender Determination" PPT courseware.

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Update Time: 2024-11-22

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

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