Living Science Solutions for Class 6 Science Chapter 18 Summative Assessment (SA I) are provided here with simple step-by-step explanations. These solutions for Summative Assessment (SA I) are extremely popular among Class 6 students for Science Summative Assessment (SA I) Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Living Science Book of Class 6 Science Chapter 18 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Living Science Solutions. All Living Science Solutions for class Class 6 Science are prepared by experts and are 100% accurate.

Page No 102:

Question 1:

A food chain cannot end at a/an
(a) herbivore.
(b) carnivore.
(c) omnivore.
(d) human.

Answer:

(a) Herbivore.
A food chain cannot end at a herbivore as they are the producers that produce food for other organisms.

Page No 102:

Question 2:

Which of these nutrients is used as an energy store by the body?
(a) starch
(b) sugar
(c) protein
(d) fat

Answer:

(d) Fat.
The body stores energy in the form of fats.

Page No 102:

Question 1:

Some animals depend on other living animals for food. What are they known as?

Answer:

Animals which depend upon other living animals for food are called parasites.

Page No 102:

Question 2:

Which nutrient forms most of our body weight?

Answer:

Water constitutes nearly 70% of our body weight.

Page No 102:

Question 3:

Which fibres dry faster−synthetic or natural?

Answer:

Synthetic fibres cannot retain water and they dry faster.

Page No 102:

Question 4:

The objects in a collection have exactly the same properties. Is it possible to classify them into different groups?

Answer:

One set of properties may be the same. However, some other properties may be different. For example, a frog is classified as an animal and so is a snake, but a pitcher plant is classified as a plant. Now, if we make a classification of insectivores (insect eaters), then the frog and the pitcher plant will be classified together.

Page No 102:

Question 5:

Which method can be used to speed up sedimentation?

Answer:

Loading can be used to speed up sedimentation.

Page No 102:

Question 1:

Why is rusting classified as a chemical change?

Answer:

The molecules of iron are not the same as the molecules of rust. In the process of rusting, new molecules are created. Further, once a metal has rusted, there is no simple way to get back the metal. As a result, rusting of metal is a chemical change.

Page No 102:

Question 2:

Give an example of a plant responding to stimuli.

Answer:

The leaves of the Mimosa plant droop when touched. This is an example of response to stimulus in plants.

Page No 102:

Question 3:

Why do plants growing in hot deserts normally have small leaves?

Answer:

Plants loose water by transpiration from the leaves. Small leaves have a smaller area and less water is lost through transpiration in such cases. Therefore, desert plants have small leaves.

Page No 102:

Question 4:

Bones cannot move by themselves. What makes bones move at the joints?

Answer:

Bones are connected to muscles by means of tendons. Muscles contract and pull on the bones by means of the tendons. This is how bones move.

Page No 102:

Question 5:

A snake has teeth, but it does not chew its food. In what way does a snake use its teeth?

Answer:

All snakes have inward curving teeth that help the snake secure a grip on its prey and swallow it. Venomous snakes also posses modified teeth known as fangs, which is used to inject venom into prey.

Page No 102:

Question 6:

What is the function of carbohydrates in food?

Answer:

Carbohydrates are a source of energy. In the process of respiration, carbohydrates from food combines with oxygen inhaled to give energy.

Page No 102:

Question 7:

What is sericulature?

Answer:

Sericulture is the cultivation of silkworms on mulberry plants to harvest silk.

Page No 102:

Question 8:

What kind of movement do molecules in a solid undergo?

Answer:

Molecules of a solid can only vibrate about their equilibrium positions.

Page No 102:

Question 9:

What does the process of distillation involve?

Answer:

The process of distillation involves boiling a mixture and then condensing the vapour obtained to get a pure liquid.

Page No 102:

Question 10:

What is the difference between the structural units of living things and those of non-living things?

Answer:

The structural units of living beings are cells. The cells are themselves living and constitute the building unit of every living being. All non-living things are made up of atoms and molecules. Molecules are the building unit of non-living things.

Page No 102:

Question 1:

Explain the difference between physical and chemical changes on the basis of changes that take  place at the molecular level.

Answer:

Physical change Chemical change
No new molecules are created. New molecules are created.
The same molecules remain before and after the physical change. The molecules of the reactant and product are different in a chemical change.

Page No 102:

Question 2:

Why are cotton clothes more comfortable to wear than nylon clothes in summer?

Answer:

Cotton clothes can allow air to pass through them, unlike nylon clothes. Also, cotton clothes can absorb sweat, which nylon clothes cannot. The air passing through the cotton clothes then evaporates the absorbed sweat and cools down the wearer. This makes cotton clothes more comfortable than nylon clothes.

Page No 102:

Question 3:

Give two ways in which living and non-living things are similar.

Answer:

Living and non-living things are made up of matter. So, both have mass and occupy space.

Page No 102:

Question 4:

What are the two main functions of roots?

Answer:

Two main functions of roots are:

  1. Roots anchor the plant to the ground and provide support.
  2. Roots are responsible for absorbing nutrients and water from the soil, which is required for the survival and growth of the plant.

Page No 102:

Question 5:

Explain the structure of the backbone.

Answer:

The human backbone is made up of 33 smaller bones known as vertebrae. Between any two vertebrae is the spinal disc that cushions movements between the vertebrae. The vertebrae near the top of the backbone are the smallest and the ones at the bottom are the largest. Each vertebra has horn like projections where muscles attach and allow movement of the spine.
Each vertebra also has a passage through it. The spinal cord passes through this passage.



Page No 103:

Question 3:

Given below are some desirable properties of fabrics. In which of these properties is cotton considered better than nylon?
(a) light weight
(b) strong
(c) absorbs water
(d) wrinkle free

Answer:

(c) absorbs water

Cotton can absorb water better than nylon.

Page No 103:

Question 4:

A molecule of water is made up of
(a) atoms of water.
(b) atoms of hydrogen.
(c) atoms of oxygen.
(d) atoms of hydrogen and oxygen.

Answer:

(d) atoms of hydrogen and oxygen.

A water molecule is made up of two atoms of hydrogen and one atom of oxygen.

Page No 103:

Question 5:

A solid has a definite volume because
(a) its molecules are tightly packed together.
(b) its molecules are loosely packed and can slip over each other.
(c) its molecules are far apart from each other and can move freely.
(d) its molecules are hard and rigid.

Answer:

(a) Its molecules are tightly packed together.

The molecules in a solid are tightly packed together. This gives a solid a definite volume.

Page No 103:

Question 6:

Which of these methods will you use to obtain both the solid and the liquid from a solution?
(a) decantation and filtration
(b) evaporation
(c) distillation
(d) separating funnel

Answer:

(c) distillation

You will use distillation to recover both the solid and liquid from a solution.

Page No 103:

Question 7:

Which of these will definitely result in a chemical change?
(a) heating
(b) burning
(c) mixing
(d) melting

Answer:

(b) Burning

Burning will definitely result in a chemical change.

Page No 103:

Question 8:

Growth in multicellular organisms occurs by
(a) addition of new external layers.
(b) addition of new internal layers of nutrients.
(c) growth in size of cells.
(d) increase in number of cells.

Answer:

(d) increase in the number of cells.

Multicellular organisms grow by cell division. This leads to an increase in the number of cells.

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Question 9:

Which of these is not a part of the male part of a flower?
(a) filament
(b) anther
(c) style
(d) pollen grains

Answer:

(c) Style

The style is a part of the pistil ,which is a female part of a flower.

Page No 103:

Question 10:

Which of these joints allows maximum movement?
(a) elbow
(b) shoulder
(c) lower jaw
(d) vertebrae joints

Answer:

(b) Shoulder

Ball and socket joints allow maximum movement. The shoulder consist of a ball and socket joint.



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