Biology 9 Lesson 41: Environment and ecological factors
1. Theoretical Summary
1.1. Environment and ecological factors
– An organism’s habitat includes all the elements that surround the organism.
There are four main types of environments:
- Water Environment.
- Terrestrial environment (above ground – air)
- Soil environment.
- Biological environment.
b. Ecological factor
– Ecological factors are factors of the environment that affect organisms.
– The ecological factors can be classified into two main categories: abiotic factors and biotic factors; in which biotic factors are divided into human factors and other biological factors.
+ Abiotic factors: light, temperature, humidity, wind, soil, water, terrain…
- Human factor: positive impact: Rehabilitation, nurturing, hybridization…. Negative impact: hunting, burning, forest fire….
- Factors of other organisms: microorganisms, fungi, animals, plants, ..
1.2. Ecological limit
– Ecological limit is the tolerance limit of an organism for a certain ecological factor.
– The ecological limit of an organism with an ecological factor is the limit of tolerance of the organism for that ecological factor.
+ Example: Temperature limit of tilapia in Vietnam.
+ Example: Temperature limit of cactus in Vietnam.
2. Illustrated exercise
Lesson 1: Rats live in a tropical rainforest, the following ecological factors affect the life of rats living in the forest: degree of flooding, ants, soil slope, air temperature, light, air humidity , snakes pecking gills, air pressure, woody plants, rotten wood, wind blowing, trees, carpets of dry leaves, caterpillars eating leaves, porosity of the soil, rainfall. Let’s divide those factors into groups of ecological factors.
There are two main groups of ecological factors:
Group of living ecological factors: ants, cobras, trees, plants, caterpillars.
Non-living ecological factors: degree of waterlogging, soil slope, air temperature, light, air humidity, air pressure, rotting wood, wind blowing, dry leaf mats, soil porosity , amount of rain.
Lesson 2: When you bring an orchid from the jungle to plant in your home garden, the ecological factors of the environment that affect the orchid will change. Please tell me the changes of those ecological factors.
Orchid trees live in dense forests often under the canopy of the forest, so the light is usually weak (the forest often has many layers of trees), when moving to the garden, the trees grow more sparsely, so the light on the orchid is strong, the humidity in the forest is higher than in the garden, the temperature in the forest is more stable than in the forest…
3.1. Essay exercises
Question 1: Describe the concept and classification of habitats of organisms?
Verse 2: Draw a diagram depicting the ecological limit of:
- The hot spring bacteria species has a temperature range from 00c to 90°c, in which the favorable point is 55°c.
- The desert bellies have a temperature range from 0°C to 56°C, of which the extreme point is 32°C.
Question 3: What is the ecological factor of the environment? Classify ecological factors?
Question 4: Humans study organisms and the environment with a purpose?
3.2. Multiple choice exercises
Question 1: The environment is:
A. Food source for organisms
B. Factors of climate affect living things
C. The set of all the elements that surround an organism
D. The factors of temperature, humidity
Verse 2: The main types of environments for organisms are:
A. Land, water, above ground-air
B. Soil, above ground-air
C. Soil, water and living things
D. Land, water, above ground- air and living things
Question 3: The habitat of green plants is:
A. Soil and air
B. Land and water
C. Air and water
Question 4: The habitat of microorganisms is:
A. Soil, water and air
B. Soil, water, air and living organisms
C. Soil, air and animal body
D. Air, water and plant body
Question 5: The habitat of roundworms is:
A. Soil, water and air
B. Intestines of animals and humans
C. Animal and human skins; domestic
D. All kinds of environment
After completing this lesson, you should:
- Describe the general concept of habitats, types of habitats of organisms.
- Explain the concept of ecological limits.
- Distinguish between abiotic and biotic factors.