"Population" PPT

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"Population" PPT

Part One: Understanding Biological Populations

They are not the same creature, they have different shapes and structures.

Species: A group of organisms that have similar shapes and structures and can mate with each other to produce offspring.

Are these the same creature? Why?

Population PPT, Part 2: Population

(1) Concept: refers to the total number of individuals of the same species living in a certain area.

For example: all the crucian carp in a pond

discuss:

1. Are all peach blossoms one species? Why?

2. Are all the carp in a market one species? Why?

3. Are all the tadpoles in a pond one population? Why?

Note: Characteristics of the population

① A certain space: small as fields and ponds, large as grasslands and oceans.

② Organisms of the same species (same species): They have size, age, male and female. They all belong to the same species and can mate with each other to produce offspring.

③The sum of individuals

Population PPT, Part 3: Characteristics of biological populations

1. Population density

(1) Concept: number of individuals in unit space

Population density = number of individual organisms/area (or volume) where the population lives

The same species often has different population densities in different areas.

Example: Asia accounts for 29.4% of the world’s land area, but is home to 58.4% of the world’s population.

South America accounts for 14.1% of the world's land area and is home to only 5.6% of the world's population.

2. Birth rate: the average number of new live births per 1,000 individuals per unit of time (year).

Birth rate = number of new individuals/total number of individuals in the population × 1000‰

Example: A population of 3,000 sparrows breeds 900 chicks in one year. Then the birth rate of this biological population in this year is: ____________.

3. Mortality rate: refers to the average number of individuals who die per thousand individuals within a unit of time (year).

Mortality rate = number of dead individuals/total number of individuals in the population × 1000‰

4. Age structure

The ratio of the number of individuals of each age group in a population commonly has the following types:

Population PPT, Part 4: Application:

①In the livestock breeding industry, farmers often control the sex ratio of animals. What is its significance?

Because people choose to control the effect in order to obtain eggs, milk and other livestock by-products

②Application of sex ratio in preventing and controlling agricultural pests.

Through large-scale trapping and killing of sexual attractants, the normal gender of crop pest populations is destroyed to achieve the purpose of preventing and controlling pests.

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

For more information about the PPT courseware of "Population", please click the "Population ppt" tab.

"Population" PPT courseware:

"Population" PPT courseware Part One: Species and Population A species is composed of a group of individuals with similar shapes and structures that can mate with each other to produce offspring. Population (1) Concept: refers to the same species living in a certain area..

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Update Time: 2024-06-29

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

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