Answer key

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Last edited 9 days ago by Learn LoopHQ.

Chapter: 08. Adaptation

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Section A: Multiple Choice Questions

(d) Pneumatic

Section B: Fill in the Blanks

habitat

gills

nocturnal

fat

wings

Section C: True or False

False

True

False

Section D: Short Answer Questions

Adaptation is the process of change or adjustment by which an organism becomes better suited to its environment. It refers to the special features that enable plants and animals to be successful in a particular environment.

Floating aquatic plants like water hyacinth are adapted to float because they have air-filled spaces between their cells, providing buoyancy. Additionally, their leaves have a waxy coating that prevents them from rotting in water.

The leaves of desert plants are often reduced to spines, which minimizes the surface area exposed to the sun. This reduction significantly prevents water loss through evaporation (transpiration) from the leaf surface, helping the plant conserve water in dry conditions.

Mountain trees like pines and firs have a cone-shaped appearance with branches that droop downward, which helps heavy snow slide off easily without accumulating and damaging the branches. Their leaves are also needle-like with a waxy coating, further preventing water loss and aiding in snow shedding.

The main purpose of air sacs in birds is to provide additional amounts of air to the lungs, ensuring a continuous supply of oxygen. This extra oxygen is vital for the high energy demands required for flight.

Section E: Diagram-Based Questions

Fish Diagram a. The body shape of the fish is called streamlined (or spindle-shaped/boat-shaped). This shape offers the least resistance when moving through water, allowing the fish to swim efficiently and quickly. b. Fish use their gills for breathing underwater, where they absorb dissolved oxygen from the water.

Camel Diagram a. The function of the hump on the camel’s back is to store food in the form of fat. This fat can be converted into energy and water, allowing the camel to survive for long periods without food or water in the desert. b. The camel’s feet have large, soft pads which help it to walk on hot and slippery sand without sinking. This provides a stable base and protects its feet from the scorching desert ground.

Section F: Differentiate Concepts

Abiotic components are the non-living physical features of a habitat, such as air, water, temperature, light, soil, and rocks. In contrast, Biotic components are the living parts of a habitat, including all plants, animals, and microorganisms (microbes) that reside there.

Section G: Long Answer Questions

The camel is remarkably adapted to desert life. Its padded feet are large and flat, allowing it to walk on soft, hot sand without sinking. The hump stores fat, which serves as a vital source of energy and water when metabolized, enabling survival during food and water scarcity. Camels can drink a large quantity of water at once and store it in specialized stomach cells. Their nostrils have flaps that close during sandstorms, and long eyelashes protect their eyes from dust. Furthermore, camels can adjust their body temperature and lack sweat glands, which helps them conserve water by preventing perspiration.

Birds possess a remarkable set of aerial adaptations for flight. Their forelimbs are modified into wings, which are powerful organs for propulsion through the air. The bird’s body has a streamlined shape, tapering at both ends, to minimize air resistance. Their bodies are covered with feathers which keep them warm, light, and aid in flying and steering. Powerful, enlarged breast muscles control the rapid movement of their wings. Their bones are pneumatic (hollow with air cavities), making the skeleton lightweight for flight, and air sacs extend from the lungs to provide extra oxygen for their energetic needs.

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