"Mammals" Main groups of animals PPT courseware 2

Description

"Mammals" Main groups of animals PPT courseware 2

By studying this section, you will know:

1. What are the main characteristics of mammals?

2. What is the relationship between mammals and human life?

Can you name the following animals?

Macaques: Live in groups in the forest, perch in trees, feed on wild fruits, bird eggs and insects.

Wild horses: inhabit grasslands and deserts, originally distributed in northern Xinjiang and other places in my country. Wild wild horses have become extinct. In the 1980s, my country reintroduced wild horses from Europe and the United States, raised them and released them into the wild.

African elephant: The largest mammal on land. It lives in forests and savannas. It mainly eats fruits such as bananas, leaves, and bark.

Main characteristics of mammals

1. Except for a few aquatic species such as whales, which have degraded body hair, all mammals are covered with hair. Body hair has a good thermal insulation effect.

2.Viviparous, lactation

Viviparous: The embryos of most mammals develop in the female body, obtain nutrients from the mother's body through the placenta, and are produced from the mother's body after development to a certain stage.

Lactation: Females use their own milk to feed their offspring so that they can grow up under superior nutritional conditions.

[Question]Why do viviparous and lactation improve the survival rate of mammalian offspring?

Tips: (1) The embryo develops in the mother's body, and the mother directly gives birth to the cubs. Viviparity improves the survival rate of offspring at birth compared with oviparity.

(2) Mothers have mammary glands that can secrete milk to feed their cubs, solving the problem of food, clothing, and nutrition for their cubs in a short time, thus greatly improving the survival rate of their offspring and enhancing their ability to adapt to the natural environment.

3. Bite, cut and chew food with teeth

Rabbit teeth are divided into incisors and molars. The incisors are suitable for cutting food, and the molars are suitable for grinding food, which are suitable for herbivorous life;

In addition to incisors and molars, wolves also have canine teeth, which are suitable for tearing food and are adapted to a carnivorous life.

The differentiation of teeth not only improves mammals' ability to ingest food, but also enhances their ability to digest food.

Class summary

1.Characteristics of mammals

2. The relationship between mammals and human life

Summarize the characteristics of mammals:

Body coat;

viviparous, lactation;

Teeth are differentiated into incisors, canines and molars.

The relationship between mammals and human life

1. Food source;

2. Maintain the stability of the ecosystem;

3. Humanity’s right-hand assistant;

4. Implement reasonable prevention and control of harmful animals.

Standard training

1. The general characteristics of herbivore tooth differentiation are ( )

A. The incisors and canines are well developed and the molars are degenerated.

B. Molars and canines are well developed and incisors are degenerated.

C. The incisors and molars are well developed and the canines are degenerated.

D. Well-developed incisors, molars and canines

2. Compared with other animals, the main reason why mammals have a higher survival rate of offspring is ( )

A. Breathe with lungs B. Live birth and breast-feeding

C. Four chambers of the heart D. Body coat

3. What belongs to mammals ( )

A. whale

B. giant salamander

C. turtle

D. squid

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For more information about the "Main Groups of Animals Mammals" PPT courseware, please click the "Main Groups of Animals PPT Mammals PPT" tab.

"Mammals" Main groups of animals PPT courseware 6:

"Mammals" Main Groups of Animals PPT Courseware 6 External Form of Rabbit The body is divided into five parts: head, neck, trunk, limbs and tail. The body is covered with hair. Coarse hair: rare, resistant to friction and plays a protective role. Villi: fine, covering the skin and playing a thermal insulation role. Heart...

"Mammals" Main groups of animals PPT courseware 5:

"Mammals" Main Groups of Animals PPT Courseware 5 Learning Objectives 1. What are the main characteristics of mammals? (Key and difficult) 2. What is the relationship between mammals and human life? Task: Read the main characteristics of mammals and complete the following questions (page 3637)..

"Mammals" Main groups of animals PPT courseware 4:

"Mammals" Main Groups of Animals PPT Courseware 4 1. Main Characteristics of Mammals 1. Except for a few aquatic species such as whales, which have degraded body hair, the body surface of mammals is covered with hair. Body hair has a very good thermal insulation effect, and mammals are warm-blooded animals. 2.Viviparous, lactating..

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Update Time: 2024-10-04

This template belongs to biology courseware People's Education Edition Biology for Grade 8, Volume 1 industry PPT template

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