VIDEO OF MICROORGANISMS

Bacteria

Viruses

Fungi

Protozoa

TYPES OF MICROORGANISMS

1. Microorganisms are very tiny living things.
2. They are found almost everywhere around us.
3. Most of them cannot be seen with the naked eye.
4. They only can be seen through a microscope.
5. Bacteria, viruses, fungi and protozoa are various types of microorganisms.

Bacteria

• come in a variety of shapes and colours.
• can be found in the air, water, soil and on the surfaces of objects and living things.

spherical

rodlike

 

 

spiral

 Viruses

• the tiniest of the microorganisms.
• can infect some bacteria, fungi, protozoa, plants, animals and humans. 

 
Fungi

• can be found on trees, in the soil and even on food such as mouldy bread and rotten oranges.
• Yeasts and moulds are examples of fungi.

mould

yeast

 

 

 Protozoa

• found mainly in ponds, lakes and rivers.

Oxytricha.sp

 

 

Amoeba.sp

 

REVISION

• A food chain shows how living things feed on other living things. It shows the food relationship among the organisms in a habitat.
• Plants are the basis of food chains because they can obtain energy directly from the Sun to make food.
• A food chain starts with a producer, followed by consumers in the subsequent levels.

• Producer(green plant)-Consumer 1(herbivore, omnivore)-Consumer 2(carnivore)-Consumer 3 (carnivore).
• Carnivores depend indirectly on plants for food. They eat herbivores or omnivores that feed on plants.
• A food web is made up of several food chains.
• A food web maintains a balance in nature by regulating the number of organisms in a habitat.  

Try Yourself

Complete the sentences below by filling in the blanks with the words given.

Plants are ____________________or ___________________sources of food for all consumers. There are three types of consumers:____________________, ____________________,and ______________________. A food _________________ shows the food relationship between different organisms. A food _______________is made up of a network of food chains.

( web   carnivores   indirect   herbivores   direct   chain   omnivores)

DIFFICULTY IN SURVIVING

1. Some species of animals eat only one type of food.

2. The populations of these animals will be greatly affected when there is a shortage of their food.

3. They face difficulty in surviving when their only source of food runs out. For example, if the bamboo forests on which the pandas depend for their survival are destroyed in the name of development, the pandas face a serious threat of extinction.

• Pandas eat only bamboo shoots and leaves.
• They will die if there are no more bamboo plants.

•  Kaolas eat only eucalyptus leaves.
• They will die if there are no more eucalyptus leaves.

• Pangolins eat only ants.
• They will die if there are no moe ants.

Try Your best:

Rats destroyed the oill palm fruit in a plantation. Owls were released to check the population of rats. Which other animal will also decrease in number over time?

A. The grasshopper
B. The earthworm
C. The snail
D. The snake

Explanation
The snakes will move to a new habitat as there will not be enough rats ti feed on.

Answer: D

CHANGES IN THE POPULATION OF CERTAIN SPECIES IN A FOOD WEB

1. Food webs are important because they maintain the population of living things in a balanced state.

2. Food webs are not permanent.

(a) Some plants and animals may die due to changes in the environment.
(b) Some animals may migrate to other habitats when there is not enough food or water.
(c) Animals from other habitats may also move in to look for more food and water.

3. When the population of a species of plants or animals in a food web changes, the population of other species in the food web are aslo affected

4. The organisms in a habitat depend on one another for food.

 



• An increase in the number of foxes will result in a derease in the number of rabbits, squirrels, mice, seed-eating birds and insect various birds.
• In turn, the number of plants increases.
• If all the rabbits in the food web die because of a disease, there will be less food for the foxes and hawks and owls.Therefore, the number of foxes and hawks and owls dereases.
• If there is an increase in the population of mice, then there will be more food for the foxes, hawks and owls. Thus, the populations of hawks, owls and foxes will also increase.

FOOD WEB IN DIFFERENT HABITATS

A food web is a network of food chains which shows the complex food relationships among living things in a habitat. Different habitats support different food webs.

The grassland food web

The soil food web

An ocean food web

A marine food web

FOOD CHAIN IN DIFFERENT HABITATS

A terrestrial food chain and a marine food chain

There are three different types of food chain such as food chain in grassland, food chain in pond and food chain in forest.

 

 

An ocean food chain

Food chain in the veld

A food chain in the temperate rain forest blome

 
Test yourself

1. A sequence showing the feeding relationship among the organisms in a habitat is 
    know as a   __________________________.

2. Food chains always start with ________________________.

3.Green plants that make their own food are called _________________________.

4. Animals that depend directly or indirectly on plants for food ara called  
     ____________________.

FUNNY GAME (PRODUCERS & CONSEMUERS)

https://www.sheppardsoftware.com/content/animals/kidscorner/games/producersconsumersgame.htm

VIDEO OF P C D

WORKSHEET(PRODUCERS & CONSUMERS)

 A producer is a living thing that makes its own food from sunlight, air, and soil. Green plants are producers who make food in their leaves.

A consumer is a living thing that cannot make its own food. Consumers get their energy by eating food. All animals are consumers.

A decomposer is a living thing that gets energy by breaking down dead plants and animals. Fungi and bacteria are the most common decomposers.

Tell whether each living thing below is a producer, consumer, or decomposer.

a. apple tree - _______________          b. hawk - _________________

c. mushroom -________________       d. carrot-  __________________

g. cougar - ___________________      h. bacteria - ______________

i. daffodil - _________________           j. pigeon - ________________

k. snake - ____________________      l. catfish - _______________

ANSWER KEY

a. apple tree – producer             b. hawk - consumer

c. mushroom – decomposer      d. carrot - producer

e. dragonfly - consumer              f. bamboo - producer

g. cougar - consumer                 h. bacteria - decomposer

i. daffodil – producer                   j. pigeon - consumer

k. snake – consumer                   l. catfish - consumer