All questions of Living Things & Environment for Year 4 Exam

Polar bears stay warm in icy environments thanks to their thick layer of blubber and dense fur. These adaptations provide insulation against the cold temperatures and help them maintain their body heat.

Bats navigate and find insect prey using echolocation. They produce sound waves at frequencies above human hearing, called ultrasound. The sound waves that is emitted by bats bounce off objects in their environment.

The camels have fat in its humps which store water.

Survival of Birds in Cold Winter in Polar Regions

Polar regions are known for their extremely cold temperatures and harsh environments, making it challenging for many animals to survive. However, some bird species have adapted to these conditions and have developed unique characteristics that enable them to thrive in these frigid areas. Among the given options, the bird that can survive in the cold winter of polar regions is the Penguin.

1. Penguin:
Penguins are well-known for their ability to survive in the icy conditions of the Polar Regions. These flightless birds have several adaptations that help them endure the extreme cold:

- Thick layer of blubber: Penguins have a thick layer of blubber, which acts as insulation to keep their bodies warm in freezing temperatures. This layer also helps them float in water.

- Waterproof feathers: Penguins have special feathers that are tightly packed and overlap, forming a waterproof barrier. This keeps their bodies dry and prevents heat loss when they swim in freezing waters.

- Huddle behavior: Penguins often huddle together in large groups to conserve heat. By standing close to each other, they create a windbreak and collectively maintain a warmer microclimate within the huddle.

- Counter-current heat exchange: Penguins have a unique circulatory system that allows them to minimize heat loss. Warm blood from their heart circulates close to cold blood returning from their extremities. This heat exchange reduces heat loss through their feet and beaks.

- Adapted breeding cycles: Many penguin species time their breeding cycles to coincide with the Antarctic summer when food is abundant. By laying their eggs and raising chicks during this period, they increase the chances of survival for their offspring.

Conclusion:
Out of the given options, only the Penguin has the necessary adaptations to survive in the cold winter of Polar Regions. These adaptations include a thick layer of blubber, waterproof feathers, huddling behavior, counter-current heat exchange, and adapted breeding cycles. These unique characteristics enable penguins to thrive in the freezing temperatures and harsh conditions of the Polar Regions.

Aerial animals are those that can fly, like birds, some insects, and bats. They have special features like wings and feathers that help them fly in the sky.

Why Broad, Waxy Leaves Help Water Lilies Float
Water lilies are fascinating aquatic plants that have adapted uniquely to their environment. One of the primary features that help them stay afloat is their broad, waxy leaves.
Key Features of Water Lily Leaves:
- Buoyancy: The broad shape of the leaves increases surface area, helping them to float on the water's surface. This design allows them to capture sunlight for photosynthesis while remaining buoyant.
- Waxy Coating: The leaves have a waxy coating that provides a waterproof barrier. This prevents water from saturating the leaves, which could make them heavy and sink.
- Lightweight Structure: The internal structure of the leaves is designed to be lightweight. This further aids in buoyancy, allowing them to stay afloat without submerging.
Comparison with Other Options:
- Long, Deep Roots: While roots anchor the plant to the sediment below, they do not directly contribute to buoyancy.
- Thick, Woody Stems: Water lilies typically have soft stems that are flexible rather than thick and woody. Woody stems would be counterproductive for floating.
- Spiny Leaves: Spiny leaves are not a feature of water lilies. They may deter herbivores but do not assist in buoyancy.
Conclusion:
In summary, broad, waxy leaves are essential for water lilies to float effectively. They provide buoyancy, prevent water absorption, and ensure the plant remains healthy and photosynthetically active on the water's surface.

A habitat provides everything an organism needs to survive, including food, water, shelter, and appropriate living conditions. For plants, this means having the necessary resources to grow and reproduce, even in varied and extreme environments like deserts, mountains, and underwater regions. Adaptations help plants thrive in these diverse habitats.

Understanding Plant Adaptation
Plant adaptation refers to the changes that plants undergo to survive in their environments. These adaptations help them deal with challenges such as harsh weather, limited water, and threats from herbivores.
Why Option C is Correct
- Using Thorns for Protection:
One of the most effective adaptations plants have developed is the use of thorns. These sharp structures serve as a defense mechanism to deter animals from eating them. By scaring off potential herbivores, plants increase their chances of survival and reproduction.
- Examples of Plants with Thorns:
- Cacti: Many cacti have thorns that not only protect them from animals but also reduce water loss by providing shade.
- Roses: Rose bushes have thorns that prevent animals from munching on their leaves and flowers.
Why Other Options Are Not Adaptations
- Growing Faster:
While growing faster can be beneficial, it is not a specific adaptation to a threat. Instead, it is a general growth response to environmental conditions.
- Changing Leaf Color in the Fall:
This is a seasonal change that helps plants prepare for winter, but it is not a defensive adaptation against threats.
- Releasing Fragrance During the Day:
While this can attract pollinators, it is not a protective adaptation aimed at survival against herbivores.
Conclusion
In summary, using thorns to scare off animals is a clear example of plant adaptation as it directly impacts the plant's ability to survive and thrive in its environment.

Understanding Hilly Trees like Pine
Hilly trees, particularly pines, are fascinating plants that exhibit unique characteristics. Let's analyze the statements provided to identify which one is false.
Statement Analysis
- a) They do not have flowers.
- This statement is true. Pines are gymnosperms, meaning they reproduce using cones instead of flowers.
- b) They are dome shaped.
- This statement is false. While some trees may have a dome shape, pines typically have a more conical or pyramidal shape, especially when they are young. Their branches extend outward and upward, creating a distinctive silhouette that is not dome-like.
- c) They are conifers.
- This statement is true. Pines belong to the conifer family, which means they bear cones and have needle-like leaves.
- d) Their leaves are needle-shaped.
- This statement is also true. Pine trees have long, slender leaves that resemble needles, which help reduce water loss and withstand cold climates.
Conclusion
In summary, the false statement among the options is that hilly trees like pines are dome-shaped. Instead, they have a conical shape, making them easily recognizable in forests and hilly areas. Understanding these characteristics helps us appreciate the adaptability and beauty of pine trees in their natural habitats.

Hydrilla leaves are thin and narrow, which allows water to pass through them easily without causing damage. This adaptation helps the plant survive in the flowing water environment. Additionally, this feature prevents the leaves from tearing due to water movement, ensuring the plant remains intact.

Floating plants like duckweed have spongy leaves filled with air spaces, which help them float on the water. This makes it easier for the plant to get sunlight and stay stable on the water surface.

Fixed aquatic plants, such as water lilies, have stomata on the upper side of their leaves to take in air. This is important because their leaves float on the water, so having stomata on top allows them to get the carbon dioxide they need for photosynthesis.