Science, Unit 3, Unit 4

 Unit - 3

Organisms and Environment

*. Mark (√) if correct and (×) if incorrect:

(a) There is a close relationship between environmental factors. √

(b) Non-living things do not help living things. ×

(c) We get food and oxygen from plants. √

(d) All nutrients required by organisms directly or indirectly from the environment is received. √

(e) Animals and plants can survive without water. ×

d. Answer the following questions:

(a) What is the environment made of?

The environment is made up of both living and non-living things. Living things include plants, animals, and other organisms. Non-living things include water, air, soil, and rocks.

(b) How do animals help plants?

Animals help plants in many ways. Some animals, like bees and butterflies, pollinate plants. This means that they carry pollen from one flower to another, which allows the plants to reproduce. Other animals, like birds and squirrels, eat fruits and nuts and then disperse the seeds in their droppings. This helps the plants to spread to new areas.

(c) What benefits can we derive from animals?

We can derive many benefits from animals. Animals provide us with food, clothing, and shelter. They also help us in many other ways, such as providing us with companionship and helping us to learn about the natural world.

(d) How do bees help the following organisms?

(A) Man (B) Plant

Bees help humans by pollinating crops. This means that they carry pollen from one flower to another, which allows the plants to reproduce. Bees also produce honey, which is a popular food. Bees help plants by pollinating them. This means that they carry pollen from one flower to another, which allows the plants to reproduce.

(e) List the environmental factors that affect animals and plants.

The environmental factors that affect animals and plants include:

• Temperature
• Water
• Sunlight
• Soil
• Air
• Pollution

(f) Mention the benefits of sunlight and soil to living things.

The benefits of sunlight to living things include:

• Sunlight provides energy for plants to produce food through photosynthesis.
• Sunlight helps to regulate the Earth's temperature.
• Sunlight is a source of vitamin D for humans.

The benefits of soil to living things include:

• Soil provides a home for many organisms, such as earthworms, bacteria, and fungi.
• Soil provides nutrients for plants.
• Soil helps to filter water.

(g) What things are needed to make food for plants?

Plants need sunlight, water, and carbon dioxide to make food. Sunlight provides the energy for photosynthesis, water is used to transport nutrients and carbon dioxide is used to make sugars.

(h) Describe the interrelationship between organisms and environment.

The interrelationship between organisms and environment is complex and dynamic. Organisms depend on the environment for food, water, and shelter. The environment, in turn, is affected by the activities of organisms. For example, plants produce oxygen, which is essential for animal life. Animals, in turn, produce carbon dioxide, which is used by plants in photosynthesis.

(i) Write what benefits animals and plants can get from water.

Animals and plants can get many benefits from water. Water is essential for life, and it is used by organisms for many different purposes, such as transportation, temperature regulation, and waste removal. Water also provides a home for many organisms, and it is a source of food for many animals.

(j) Earthworms are very useful organisms for soil and plants. To this statement Write with logic.

Earthworms are very useful organisms for soil and plants. They help to aerate the soil, which allows plants to get the oxygen they need. Earthworms also help to break down organic matter in the soil, which releases nutrients that plants can use.

(Interrelationship between Organisms and Environment)

*. Answer the following questions:

(a) Five effects on the environment due to excessive population growth Write the negative effects.

Here are five negative effects on the environment due to excessive population growth:

1. Deforestation: As the population grows, more land is needed for housing, agriculture, and industry. This leads to deforestation, which destroys habitats for plants and animals and contributes to climate change.
2. Pollution: More people means more waste, which can pollute the air, water, and soil. This can lead to health problems for humans and other animals.
3. Water scarcity: As the population grows, demand for water increases. This can lead to water shortages, which can have a devastating impact on agriculture, industry, and human health.
4. Climate change: The greenhouse gases produced by human activities, such as burning fossil fuels, trap heat in the atmosphere and cause the Earth's temperature to rise. This is leading to climate change, which is causing more extreme weather events, such as droughts, floods, and heat waves.
5. Loss of biodiversity: As the population grows, more land is converted to human uses, which destroys habitats for plants and animals. This is leading to the loss of biodiversity, which is the variety of life on Earth.

(b) How does the increase in population cause air pollution?

The increase in population causes air pollution in several ways. First, more people means more cars, factories, and other sources of emissions. Second, more people means more waste, which can be dumped in landfills or burned, releasing harmful gases into the air. Third, deforestation reduces the amount of vegetation that can absorb carbon dioxide, a greenhouse gas that contributes to air pollution.

(c) Negative impact of population growth on forest cover in an area Mention.

The negative impact of population growth on forest cover in an area includes:

• Deforestation: As the population grows, more land is needed for housing, agriculture, and industry. This leads to deforestation, which destroys habitats for plants and animals and contributes to climate change.
• Fragmentation: Forest fragmentation occurs when forests are broken up into smaller patches. This can make it difficult for plants and animals to move around and find food and mates.
• Degradation: Forest degradation occurs when forests are damaged by human activities, such as logging, mining, and agriculture. This can make forests less productive and less able to provide the ecosystem services that humans and other animals rely on.

(d) How does population growth create water scarcity?

Population growth creates water scarcity in several ways. First, more people means more demand for water. Second, climate change is causing glaciers and other sources of water to melt, reducing the amount of water available. Third, deforestation reduces the amount of water that can be stored in the soil, making it more difficult to capture and store rainwater.

(e) What happens in the air when animal population increases and plant population decreases change?

When the animal population increases and the plant population decreases, the air becomes more polluted. This is because animals produce more waste, which contains harmful gases. When there are fewer plants, there are fewer trees to absorb these gases.

(f) How due to disorderly operation of industries and factories The amount of garbage increases, write.

 The disorderly operation of industries and factories leads to an increase in the amount of garbage. This is because industries and factories produce a lot of waste, which is often not disposed of properly. This can lead to pollution of the air, water, and soil.

(g) Trees have been felled in the fields around a village. This

Because the people there are now dry water sources, droughts and landslides

Natural calamities like going have to be faced. The atmosphere there

What can you do to keep it clean?

The people of the village can plant trees to help keep the atmosphere clean. They can also reduce their consumption of water and energy, and they can recycle and compost their waste.

In addition to the above, excessive population growth can also lead to a number of other problems, such as:

• Increased crime rates
• Traffic congestion
• Overcrowded schools and hospitals
• A decrease in the quality of life

 Unit - 4

Classification of Living Beings

(a) Which animal has a soft body?

There are many animals that have soft bodies, including jellyfish, worms, snails, and slugs.

(b) Name any five animals that do not have a backbone.

Here are five animals that do not have a backbone:

• Jellyfish
• Worms
• Snails
• Slugs
• Insects

(c) Write any three characteristics of vertebrate animals.

Here are three characteristics of vertebrate animals:

• They have a backbone.
• They have a skull.
• They have a central nervous system that runs through their backbone.

(d) List any five animals that have a backbone.

Here are five animals that have a backbone:

• Humans
• Fish
• Birds
• Reptiles
• Amphibians

(e) Write the difference between animals with backbone and animals without backbone.

The main difference between animals with backbone and animals without backbone is that animals with backbone have a spine, while animals without backbone do not. Animals with backbone are also known as vertebrates, while animals without backbone are known as invertebrates.

(f) Mention two ways in which animals produce offspring.

There are two main ways in which animals produce offspring: sexual reproduction and asexual reproduction.

• Sexual reproduction is when two animals come together to create offspring. The offspring will have a combination of genes from both parents.
• Asexual reproduction is when an animal creates offspring without the help of another animal. The offspring will be an exact copy of the parent.

Plants around us

*. Answer the following questions:

(a) Mention the types of plants based on size.

Plants can be classified into three types based on their size: herbs, shrubs, and trees.

• Herbs are small, soft-stemmed plants that usually do not have woody stems. They typically die back to the ground at the end of the growing season.
• Shrubs are woody plants that are smaller than trees. They typically have multiple stems and do not grow as tall as trees.
• Trees are woody plants that are larger than shrubs. They typically have a single stem and grow tall.

(b) Write the characteristics of plants belonging to the category of weeds.

Weeds are plants that are considered undesirable in a particular location. They are often fast-growing and can spread quickly. Some common characteristics of weeds include:

• They are able to grow in a variety of conditions.
• They are able to produce a lot of seeds.
• They are able to spread quickly.
• They are difficult to control.

(c) Which plants are called trees? Write an example.

Trees are woody plants that are larger than shrubs. They typically have a single stem and grow tall. Some examples of trees include:

• Oak
• Maple
• Pine

(d) Write the names of any three plants belonging to the butane group.

The butane group is a group of plants that are characterized by their ability to produce butane. Some common butane-producing plants include:

• Tobacco
• Tomato
• Potato

(e) Write the characteristics of plants found in water.

Plants found in water are adapted to live in aquatic environments. They have special features that allow them to survive in water, such as:

• They have roots that can absorb water and nutrients from the water.
• They have leaves that are adapted to float on the water or to absorb sunlight underwater.
• They have stems that are flexible and can bend with the current.

(f) Name any four plants found in water.

Some common plants found in water include:

• Water lilies
• Cattails
• Reeds
• Algae

more solution update soon.......