Knowledge. Through this lesson, students must consolidate the following knowledge:

LESSON 38: BASIC CHARACTERISTICS OF BIOLOGICAL POPULATIONS (cont.)

I. OBJECTIVES

1. Knowledge . Through this lesson, students must consolidate the following knowledge:

- State the concept of size, minimum size, maximum size

- Describe the factors affecting population size.

- Present the concept of population growth

- Describe the growth characteristics of populations in the following cases: unrestricted environmental conditions and restricted environmental conditions.

- State the growth of human population.

2. Skills .

Train students in skills:

- Search and process information through text and image channels.

- Show confidence through expressing opinions.

- Creative thinking

- Active listening.

3. Attitude

Educating students about population growth, rights and obligations of Vietnamese citizens regarding population work

4. Ability to aim

- Develop problem solving and creativity skills

- Develop the ability to learn about nature and society

- Develop language and physical abilities

II. PREPARATION OF TEACHERS AND STUDENTS

1. Teacher: - Students collect pictures then the teacher will choose some typical pictures to use in the lesson.

2. Students: - Students collect pictures H38.1-4 to use in class.

III. TEACHING METHODS AND TECHNIQUES:

Teachers flexibly choose the following teaching methods and techniques to suit the lesson.

Group activities based on projects and creative experiences + guiding students to develop self-learning ability + hands-on kneading + some other methods

Tablecloth technique + puzzle technique + expert role playing + some other techniques

IV. TEACHING PROCESS:

A. STARTUP

* Target :

- Stimulate students' interest in learning new lessons

- Train students' critical thinking skills.

* Method: Presentation, analysis, commentary

* Competency orientation: problem solving, cognitive ability

The teacher lets students play the Prediction game.

What is population size? What factors affect population size?

 SP to be achieved after completing the activity:

Maybe you are interested!

Think about the problem;

Participate in reading comprehension activities to find answers to the warm-up situations,

From the above question-posing method, the teacher leads students into new activities: Knowledge formation activities.

B: KNOWLEDGE FORMATION

* Target :

- State the concept of size, minimum size, maximum size

- Describe the factors affecting population size.

- Present the concept of population growth

- Describe the growth characteristics of populations in the following cases: unrestricted environmental conditions and restricted environmental conditions.

- State the growth of human population.

* Method: Presentation, analysis, commentary

* Competency orientation: problem solving, cognitive ability

-What is population size?

Example?

-What are the units of QT size measurement?

-What is the minimum size?

-When the size of the population decreases below the minimum level? Why does the population decrease -> become extinct? (+The number of individuals is small, mutual support is reduced -

>QT is not able to withstand mtr.

+Reduced fertility

+Inbreeding often occurs)

-Lecture : Minimum distance specifies the required distance for individuals to meet, perform reproduction and other life functions.

-What is the maximum size? If the number of individuals exceeds the maximum? (-> exceeds the maximum -> competition, pollution, disease,...

-> migration, mortality

- Students read the information in the textbook and answer.

- Students consult groups to answer.

- Students read the information in the textbook and answer.

- Students discuss in groups and answer:

+ The chance of males and females meeting is low, so the ability to reproduce is reduced.

+ The number of individuals in the population is too small, the support between individuals is reduced -> the population is unable to resist,..

- Students read the information in the textbook and answer.

+ Impossible. Therefore, individuals must compete, mortality increases,

reduced fertility,…-> edema

V. Population size: 1. Minimum and maximum size

a. Size:

Population size or number of individuals in a population is the total number of individuals or the output or total energy of the individuals in the population.

-Population size has two extremes:

+ Minimum size: the smallest number of individuals that a population must have, enough to ensure the fish population's ability to maintain its species -

>species specific

+Maximum size: the largest number of individuals that a population can achieve, balanced with the strength of the environment.

-Species with small body size

->population has many individuals and vice versa

b. Density:

Population density is the population size calculated per unit area or volume.

Eg: Textbook

Students pay attention;

-Please indicate the correlation between body size and QT size?

- Teacher asks students to answer the textbook command?

- What is population density?

- Population KT is described by the following general formula:

N t = N 0 + B – D + I – E

->What causes the variation in body size?

- The teacher hangs picture 53.1 and asks students to state the concept and meaning of the 4 causes above?

-Lecture: In the above 4 causes, the first 2 causes are the inherent nature of the substance, which often determines the change in the substance's SL.

- What factors do the reproductive rate and mortality rate of a population depend on? (Reproduction rate: depends on the number of individuals in a litter, the number of litters, the male-female ratio, etc. Mortality rate: depends on the state of the population, the living conditions of the environment and the level of human exploitation)

-What is the survival rate?

- Based on figure 53.2: describe the life curves of 3 groups of animals?

- Teacher explains: -> conclusion.

-The growth in size of the body depends on

on the 4 factors above.

environmentally friendly

+ Students discuss in groups to answer: elephant, mountain goat, rabbit, rat, squirrel, coconut beetle.

- Students read textbooks and answer.

- Students use textbook information to answer: birth rate, death rate, immigration rate, emigration rate.

- Students observe pictures + information in textbooks, discuss in groups and answer.

- Survival rate: is the number of individuals alive at a certain point in time.

- Students discuss in groups to answer

- Students answer the questions in the textbook.

- Many species have small body size and short lifespan (microorganisms, algae, insects, 1-year plants) and grow exponentially.

- Students read the information in the textbook and answer.

- HS explains

2. Factors causing population size fluctuations: Formula: N t = N 0 + B – D + I – E

In which: N t , N 0 : Individual number of QT at time t and 0

B: birth rate D: death rate I: immigration rate E: emigration rate

-Reproduction rate: Is the number of new individuals born by a population in a certain period of time.

- Mortality rate: the number of individuals of a population that die in a given period of time.

-Immigration level: Number of individuals moving in from other populations.

-Migration level: A part of individuals leave the population to live in another population.

* Survival rate: is the number of individuals alive at a certain point in time.

CT: S s = 1 – D

In which: 1 is the population size considered as 1 unit; D: mortality rate (D≤1).

-Each group of organisms has a different survival curve, and species tend to increase their survival rate in different ways.

3. Body size growth:

If b is called the instantaneous specific birth rate; d: death rate; r: is the coefficient.

CT: r = bd

If b > d: qcan increase quantity b = d: qcan be stable.

b < d : can reduce quantity

VI. GROWTH OF POPULATIONS

Increase in body size

High).

-Teacher lecture

- What is the ideal environment? Which curve does it follow? expression?

- Characteristics of unrestricted environment?

+Expression: ∆N = (b- d).N

∆t

∆N = rN

∆t

Lecture: This is a power function whose corresponding curve is half of a parabolic curve or has a J-shape (not real), small-sized species with short lifespans have a growth pattern close to potential growth with a J-shaped curve.

- What are the characteristics of limited mtr?

- Expression:

∆N = r. N (K -N)

∆tK

- What expression and curve does this growth pattern follow?

- Teacher asks students to explain

53.4 Textbook

- Teacher explains

under ideal environmental conditions (unlimited) or at biological potential:

-In an ideal environment, the birth rate of an organism is maximum and the death rate is minimum.

-The number increases exponentially with a characteristic J-shaped curve

-Small-sized, short-lived species have growth patterns close to potential growth patterns.

b. Body size growth under limited environmental conditions.

-In most large species, population growth only reaches the limit of equilibrium with the tolerance of the environment.

-S-shaped curve

C: PRACTICE

Objective: - Practice to help students consolidate what they already know.

- Train students' self-study skills, communication and cooperation skills, and problem-solving skills.

Teaching method: Assigning homework

Competency development direction: problem solving, communication skills, cognitive skills.

Question 1: The size of a population can increase when

A. immigration is less than emigration. B. the birth rate is equal to the death rate.

C. the birth rate is less than the death rate. D. the birth rate is greater than the death rate.

Question 2: To determine the maximum size of a population, one needs to know the number of individuals in the population and

A. birth rate and death rate of the population.

B. distribution pattern of individuals in the population.

C. factors that limit population growth.

D. the ability of the environment to provide life.

Question 3: In which of the following cases can the size of a population increase?

A. The birth rate is greater than the death rate. B. The birth rate is equal to the death rate.

C. Immigration is less than emigration. D. Birth rate is less than death rate.

Question 4: When does a population reach a stable level in numbers?

A. When the number of individuals born is equal to the number of individuals dying and the male to female ratio is equal.

B. When the number of individuals born equals the number of individuals dying and there is no emigration.

C. When the number of individuals born equals the number of individuals dying and there is no immigration.

D. When the number of births equals the number of deaths and the number of immigration equals the number of emigration.

Question 5: Consider a population of organisms, the size of the population does not depend on the factor

A. male to female ratio. B. reproductive capacity.

C. individual mortality rate. D. individual immigration and emigration.

Question 6: If the source of life is not limited, the population growth graph is in the form of

A. steadily increasing. B. J-shaped curve.

C. S-shaped curve. D. steadily decreasing.

D: APPLICATION (8')

Objective: - Create opportunities for students to apply acquired knowledge and skills to new situations and contexts, especially in real life.

-Training thinking and analytical skills.

Teaching methods: Group teaching; problem-solving teaching; presentation method; use of visual aids

Capacity development orientation: Experimental capacity, observation capacity, creative capacity, communication capacity. Self-confidence, independence, communication.

- How do the four factors affect a population with a stable size?

- Distinguish between types of population growth?

E: EXPAND (2')

Objective: To explore and expand knowledge, summarize all the knowledge learned

Teaching method: Assigning tasks

Capacity development orientation: autonomy-self-study, understanding nature and society, problem solving

Mind mapping of lesson content

death

4. Guide students to study and do homework (2 minutes)

- Read lesson 39 first and answer the questions:

- Describe the types of population fluctuations?

- What is population equilibrium?

Lesson 40

Lesson 39: CHANGES IN THE NUMBER OF INDIVIDUALS IN A POPULATION

I. OBJECTIVES

1. Knowledge

+ State the forms of variation in the number of individuals in a population and give illustrative examples.

+ State the causes of fluctuations in the number of individuals in a population.

+ Describe the population mechanism that regulates the number of individuals in the population.

+ State the concept of balance in a population and the self-regulation mechanism of a population.

2. Skills

- Practice observation skills and analyze visual channels to collect information.

- Develop theoretical thinking ability to analyze, synthesize, compare and generalize

- Practice skills in analyzing environmental factors

3. Attitude

- Forming a dialectical materialist view of living things on earth.

- Be aware of protecting the biodiversity of living species.

- Building awareness of protecting the natural environment

4. Ability to aim

- Develop problem solving and creativity skills

- Develop the ability to learn about nature and society

- Develop language and physical abilities

II. PREPARATION OF TEACHERS AND STUDENTS

1. Teacher: - Students collect pictures then the teacher will choose some typical pictures to use in the lesson.

2. Students: - Students collect pictures H39.1-3 to use in class.

III. TEACHING METHODS AND TECHNIQUES:

Teachers flexibly choose the following teaching methods and techniques to suit the lesson.

Group activities based on projects and creative experiences + guiding students to develop self-learning ability + hands-on kneading + some other methods

Tablecloth technique + puzzle technique + expert role playing + some other techniques

IV. TEACHING PROCESS:

A. STARTUP

* Target :

- Stimulate students' interest in learning new lessons

- Train students' critical thinking skills.

* Method: Presentation, analysis, commentary

* Competency orientation: problem solving, cognitive ability

The teacher lets students play the Prediction game.

What causes fluctuations in the number of individuals in a biological population?

 SP to be achieved after completing the activity:

Students pay attention;

Think about the problem;

Participate in reading comprehension activities to find answers to the warm-up situations,

From the above question-posing method, the teacher leads students into new activities: Knowledge formation activities.

B: KNOWLEDGE FORMATION

* Target :

+ State the forms of variation in the number of individuals in a population and give illustrative examples.

+ State the causes of fluctuations in the number of individuals in a population.

+ Describe the population mechanism that regulates the number of individuals in the population.

+ State the concept of balance in a population and the self-regulation mechanism of a population.

* Method: Presentation, analysis, commentary

* Competency orientation: problem solving, cognitive ability

* Activity 1:

The teacher asks students to study figure 39.1.

Teacher: Based on Figure 1.1, describe the fluctuations in the number of rabbits and Canadian lynx.

?. What is seasonal variation? Give an example?

- Students study figure 39.1

- Seasonal fluctuations: Is the increase or decrease

number of individuals in the population

I. CHANGES IN THE NUMBER OF INDIVIDUALS

Population change is the increase or decrease in the number of individuals in a population over time.

1. Cyclical fluctuations Seasonal fluctuations: Is the increase or decrease

number of individuals in the population

?. What will happen when the rabbit population decreases?

?. What is multi-year cyclical fluctuation? Give an example.

* Activity 2:

- The teacher lets students study section 2, combined with observing image 1.1

?. What is non-periodic fluctuation?

? . What causes non-periodic fluctuations? Give examples for each cause?

* Activity 3:

The teacher asks students to study section II.1.

?. At what stage does abiotic factors affect a population and are most likely to cause death to individuals? Why?

season

- Students commented: The number of rabbits increased  the number of lynxes increased, because lynxes need more food, the number of rabbits decreased

- Students stated that the number of lynxes decreased and the number of rabbits increased.

- Multi-year cyclical fluctuations: is the increase or decrease in the number of individuals in a population corresponding to a certain number of years.

- Students study section 2, observe figure 1.1

- Is the phenomenon of sudden increase or decrease in the number of individuals in a population.

- Reason:

+ Due to human activities

+ Due to unusual incidents: floods, droughts, epidemics.

+ Due to favorable living conditions but no competitors.

Students study section II.1

- Impact of abiotic factors

season

For example :

+ Chewing frogs increase in number during the rainy season

+ Mosquitoes increase in number in summer

- Multi-year cyclical fluctuations: is the increase or decrease in the number of individuals in a population corresponding to a certain number of years.

For example : The fish species on the coast of Peru fluctuate in number every 7 years.

1. Non-cyclical fluctuations:

Concept: Is the phenomenon of sudden increase or decrease in the number of individuals in a population.

- Reason:

+ Due to human activities

+ Due to unusual incidents: floods, droughts, epidemics.

+ Due to favorable living conditions but no competitors.

II. CAUSES OF FLUCTUATION AND ADJUSTMENT OF POPULATION NUMBER

1. Causes of fluctuations in population numbers

- Quantity fluctuations

What do you think about the quantity relationship between rabbits and lynxes ?

?. How do biotic factors affect populations?

?. How can the human factor change the number of individuals in a population?

?. Do external factors have separate effects on biological populations?

? . How do ecological factors affect populations?

* Activity 4:

- The teacher raises the question: The change in population size is due to the combined impact of ecological factors. So how do biological populations react to environmental impacts?

?. Population equilibrium is maintained through regulation of which structural elements of the population?

?. What is the density regulation mechanism?

?. The phenomenon of thinning in plants or the secretion of substances

chemically weakens copper

Birth during the breeding season or the juvenile stage of an organism causes the most dramatic fluctuations in the population.

- The impact of biotic factors is clearly shown in the reproductive capacity of the population, in the density of predators, parasites, prey, and competitors.

- The factors determining the variation in the number of individuals in a population can vary depending on the population and the stage in the life cycle.

- Students answer

Students can present: if adapted, the population will survive and increase in number; if not adapted, the number will decrease or lead to extinction or spread to other places.

- The mechanism of population density regulation is the adjustment of the correlation between

Birth rate and death rate

of individuals in a population is due to one or a set of ecological factors that affect the birth rate, death rate and dispersal of the population.

- The impact of abiotic factors during the reproductive season or the young stage of organisms causes the strongest fluctuations in the population. The impact of biotic factors is clearly shown in the reproductive capacity of the population, in the density of predators, parasites, prey, and competitors.

- The factors determining the variation in the number of individuals in a population can vary depending on the population and the stage in the life cycle.

2. Adjustment of population numbers:

- Changes in environmental life such as climate, soil, food, habitat... will lead to changes in population numbers.

- When population density increases, it leads to lack of food, shelter, many diseases, many individuals will die, then population density is adjusted back to balance.

3. Population equilibrium

- Population equilibrium is a state in which the number of individuals in the population is at a stable level.

- Density regulation mechanism

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