Exam practice

The ability of a living thing to live well in its surroundings is called adaptation.

Aquatic animals breathe through gills or skin.

Terrestrial plants have hard and strong stems.

Plants that grow in hot and dry places can store water.

The stem of aquatic plants is flexible (soft and bends without breaking). The word “air” is not needed.

The same question is sometimes asked about animals:

Wings help a bird (or a bat, or an insect) fly.

Gills let a fish breathe under water: they take in the oxygen dissolved in the water.

Sharp claws help an animal catch and hold its prey (a cat catching a rat), or dig a hole.

A pointed, strong snout helps a rat or a rabbit dig a hole in the ground (and push into narrow places).

Broad paws with sharp claws help a tiger, a dog or a bear run and catch its prey.

Draw each with the parts that show its adaptations, and label them.

Draw neat outlines with these parts labeled:

• Fish: streamlined body, scales, fins (dorsal, tail and the pairs underneath), gill cover, eye, mouth (as in Figure 3.6).
• Cat: four legs with paws and claws, whiskers, sharp teeth, tail.
• Bird: beak, wings with feathers, two legs with toes, tail feathers.
• Bean plant: a thin stem twining round a stick, leaves in threes, flowers, pods, roots.
• Pine tree: a cone-shaped tree with a straight trunk, branches sloping down, needle leaves and cones.

• a.Parrot: a strong, hooked beak. It cracks hard nuts and seeds and bites into fruit. It also uses its beak like a third foot to climb.
• b.Woodpecker: a long, strong, chisel-like beak. It drills holes in tree trunks to find insects and to make its nest.
• c.Duck: a flat, broad beak. It picks up food from water and soft mud, and lets the water drain out.
• d.Hen: a short, pointed beak. It picks up grains and small insects from the ground.
• e.Eagle: a sharp, hooked beak. It tears the flesh of the animals it catches.

1. Strong legs and muscles to walk and run (horse, deer).
2. Broad paws with strong claws to run and catch prey (dog, tiger).
3. Thick fur in cold places to stay warm (yak, snow leopard); thin fur in hot places.
4. Thick, dry skin in deserts to lose little water (camel).
5. They breathe air with lungs.

1. A streamlined body, which makes swimming easy.
2. Fins to swim and steer.
3. Gills to breathe the oxygen dissolved in water.
4. A slimy, slippery body covered with scales.

The Himalaya is very cold. The thick, long fur and hair trap a layer of air next to the body. Air doesn’t let heat pass through easily, so the body’s heat stays in and the cold stays out, like a thick woolen jacket. So the sheep and the yak stay warm even in snow.

A fish has gills, which take the oxygen dissolved in water; a streamlined body and fins to swim; and slippery scales. A rat breathes air with lungs, which can’t take oxygen from water, so it would drown. It has legs for walking and digging, not fins for swimming. So the fish’s body suits water, and the rat’s suits land.

Broad paws spread their weight, grip the ground, and help them run and climb. Strong, sharp claws catch and hold prey, so they can hunt. A bear also uses its claws to dig for roots and insects and to climb trees.

Not in an ordinary flower pot of soil. A lotus is an aquatic plant. Its roots grow in wet mud at the bottom of a pond, its leaf stalks are soft and need water round them, and its broad leaves float on the water. In a pot of ordinary soil with holes for draining, it would dry out and die.
She can grow it if she makes a small pond for it: a big tub or pot without holes, with wet mud at the bottom and water above it, kept full, in a sunny place. Then the lotus has the conditions it is adapted to.

A cat may eat rice and milk that people give it, but it needs meat to stay healthy and hunts rats and birds: it is a carnivore.

• a.Cow: herbivore. No upper front teeth, and broad, ridged grinding teeth to chew grass.
• b.Dog: omnivore. It has pointed canines to bite meat, and also some flatter teeth at the back for chewing other food; it eats rice, bread and meat.
• c.Tiger: carnivore. Very long, pointed canines and sharp, blade-like cheek teeth to cut meat.

1. They eat only plants: grass, leaves, grains and fruits.
2. They have broad, flat teeth to chew and grind plants.
3. They have a long alimentary canal, because plants are hard to digest.
4. Many of them, like the cow and goat, chew the cud.

1. Long, sharp, pointed teeth to catch, kill and tear prey.
2. Sharp, strong claws (or a hooked beak and talons in birds) to catch and hold prey.
3. A short alimentary canal, because meat is easy to digest.

Animals that eat both plants and animals are called omnivores. Examples: bear, dog, crow, human being.

For example: herbivores: cow, buffalo, goat, sheep, rabbit, horse, deer; carnivores: cat, frog, lizard, eagle (chil), owl, snake.

Yes. An omnivore is an animal that eats both plants and animals. A dog eats meat and bones, but also rice, bread, roti and vegetables, and it digests them well. So, by the food it eats, the dog is an omnivore. (Its long, pointed canines show that its wild relatives, the wolves, were mainly meat-eaters; dogs living with people for thousands of years have come to eat much more plant food.)

A human being is an omnivore. We eat plant foods (rice, wheat, dal, vegetables, fruits) and animal foods (meat, fish, eggs, milk). Our teeth suit both: sharp front teeth (incisors) to bite, small canines to tear, and flat back teeth (molars) to grind grains.

A vertebrate’s body has a vertebral column.

Fish breathe through gills.

Most reptiles have a three-chambered heart.

The bones of birds are light and hollow.

Animals whose body temperature doesn’t change, but stays the same, are called homeothermic (warm-blooded). The word “poikilothermic” is not needed.

The fish and the seahorse both breathe through gills; one of them is left over.

Into five classes: Pisces (fish), Amphibia (amphibians), Reptilia (reptiles), Aves (birds) and Mammalia (mammals).

1. Their front limbs have become wings.
2. Their bones are light and hollow, so the body is light.
3. Their body is covered with feathers, which make the wings broad and the body smooth.
4. Their body is streamlined, and strong chest muscles flap the wings.

Because it has the features of reptiles: its skin is dry and covered with hard scales; it breathes through lungs; it crawls; it lays eggs on land; it is cold-blooded; and its heart has three chambers.

i.

ii.

iii.

iv.

• i.Fish: gills to breathe; fins to swim (also: scales, two-chambered heart).
• ii.Amphibians: moist, slimy skin; live both in water and on land (also: three-chambered heart, tadpoles with gills).
• iii.Reptiles: dry skin with hard scales; lay eggs on land (also: crawl, breathe through lungs).
• iv.Birds: feathers; wings and light, hollow bones (also: beak, four-chambered heart).
• v.Mammals: hair on the body; give birth and feed their young with milk (also: four-chambered heart, external ears).

Draw a fish from the side, like Figure 3.6, and label: mouth, eye, gill cover (gills under it), scales, dorsal fin, pectoral fin, pelvic fin, anal fin, tail fin, lateral line.

Hatch from eggs: hen, crow, snake, frog, fish, tortoise.

Born as young ones: cow, dog, human, goat, bat, whale.

• i.Wall lizard: dry, scaly skin; toe pads with tiny hairs to walk on walls (it can also drop its tail to escape).
• ii.Pigeon: body covered with feathers; wings and light, hollow bones to fly.
• iii.Frog: moist, slimy skin; lives both in water and on land, breathing through its skin and lungs.

Alike: both are vertebrates; both live in water; both have a streamlined body and fins (or flippers) to swim.

Because both have the features of mammals: they give birth to young ones and feed them milk; they have hair on the body (a whale has only a few hairs); they breathe with lungs; and they have a four-chambered heart and are warm-blooded. That the bat flies and the whale swims doesn’t change this.

Non-flowering plants are called cryptogams.

Plants of the fungi group have no chlorophyll.

Simple plants without chlorophyll can’t make their own food.

The fine, hair-like threads that hold a moss to the ground are called rhizoids. The word “root” is not needed.

Flowering plants are called phanerogams.

Flowering: mustard, rice, marigold (or maize, mango, rose).

Non-flowering: moss, fern (niguro), mushroom (or the green algae of a pond).

Draw a mustard plant (or any small flowering plant) and label: taproot with branch roots, stem, node, leaf, bud, flower, fruit (pod). See Grade 7’s diagram of a mustard plant.

Mustard is more developed. It has well-developed roots, stems and leaves, and also flowers, which make seeds inside fruits; a seed carries food for the young plant and a tough coat that protects it. A fern has roots, stems and leaves, but no flowers and no seeds: it makes tiny spores, and it needs damp places to grow from them.

Draw two circles that overlap. Write what only the pine has in the left part, what only the peepal has in the right part, and what both have in the middle.

Only pine: needle-shaped leaves; seeds naked on the scales of cones; no flowers and no fruits; cone-shaped tree; a gymnosperm.

Both (the middle): both are tall trees with woody trunks; both have roots, stems and leaves; both have chlorophyll and make their own food; both make seeds (both are phanerogams).

Only peepal: broad, heart-shaped leaves with a long pointed tip; tiny flowers hidden inside its figs; seeds inside fruits; an angiosperm (a dicot).