Our Environment Science - Our Environment

Fill in the following blanks with suitable words:
Ultraviolet rays can cause skin______________ .

Fill in the following blanks with suitable words:
In nature, all green plants are ____________ whereas animals are consumers.

Fill in the following blanks with suitable words:
Grass →____________→Human

Fill in the following blanks with suitable words:
A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a _____________.

Fill in the following blanks with suitable words:
Lettuce →____________→ Fox

State whether the following statements are true or false:
In biology, human beings are called producers.

State whether the following statement is true or false:
Only 10 per cent of the light energy given by the sun is available for transfer at each higher trophic level in a food chain.

Secondary consumers and tertiary consumers, both are carnivores.

What percentage of energy available at the producer level is transferred at successive trophic levels in a food chain?

Write an aquatic food chain.

What type of substances are the major pollutants of the environment? Name two such substances.

What percentage of the solar energy is trapped and utilised by the plants?

Which one term in the following includes the others?
Air, flora, fauna, environment, water, sunlight, soil.

How are most of the solid wastes in urban areas disposed of?

Define decomposers. Name one decomposer.

What would happen if the ozone layer in the atmosphere completely disappears?

What is a food chain? Give one example of a simple food chain.

Define an ecosystem. Give examples of any two ecosystems.

Which of the following are biodegradable and which non-biodegradable?
Glass bottle, Paper, Ball point pen refill, Hay, DDT, Wheat, Cake, Wood, Polythene bag, Jute bag, Cotton cloth, Grass, Vegetable peels.

What is meant by a primary consumer, secondary consumer and a tertiary consumer? Give one example of each.

What is ozone? How is it formed?

With the help of a flow diagram, describe how energy from the sun flows through various trophic levels.

What is a ‘food web’? Show its formation.

Some hunters are roaming in the plush green forest of Africa. They spot a deer and kill it. They decide to roast the deer there and then and eat it. When the hunters had just finished enjoying the feast of roasted deer, a lion attacks them. The lion kills one of the hunters and eats his flesh.

1. Write a food chain which provides food to lion in this case.
2. Which animal (other than deer) the lion could look for food if he did not get the hunter as prey?
3. Which other animal in the forest could have been in place of lion?
4. How does the above food chain differ form the food chain such as: plants → goat → man?

How does a biodegradable waste differ from a non-biodegradable waste? Give two examples of non- biodegradable wastes which pollute our environment.

How much energy will be available to hawks in the food chain comprising hawk, snake, paddy and mice, if 10,000 J of energy is available to paddy from the sun?

A food chain occurring in the sea which provides food for many people can be written as:
phytoplankton → zooplankton → X → Y

1. Name one phytoplankton.
2. Name two zooplanktons.
3. What could be X?
4. Name the organism which Y could be.
5. Which organism in the above food chain is a (i) primary consumer, and (ii) tertiary consumer?