Ch 9A. Living organisms and their surroundings -WORKBOOK ANSWER

 

Ch 9. Living organisms and their surroundings - A

I.
1. Choose the correct option.
(a) Which of the following is an abiotic component of the environment?
i. sunlight ii. plant

iii.	bacteria	iv. animals
Ans: sunlight
(b) Which of the following is not a characteristic of living organism?
i. iii.	respond to stimuli movement	ii. respiration iv. unable to adapt

Ans: unable to adapt
2. State true or false:
(a) Plants like bryophyllum reproduce through leaves.
Ans: True
(b) Amoeba is an unicellular organism.
Ans: True
(c) The movement of a sunflower in the direction of the sun is an example of
tropism.
Ans: True
3. Give two examples of:
(a) Decomposers
Ans: bacteria and fungi
(b) Nocturnal animals
Ans: Owls, bats, cockroaches
(c) Plants that reproduce through stems.
Ans: ginger, potato
(d) Plants that grow from seeds.
Ans: gram, wheat, tomato, mango, peepal
Objective type questions
4. In the following questions, two statements are given- one labelled
Assertion (A) and the other labelled Reason (R). Read the statements
carefully and choose the correct alternative (A), (B), (C) and (D) as given
below.
(A) Both A and R are true and R is correct explanation of the assertion.
(B) Both A and R are true but R is not the correct explanation of the
assertion.
(C) A is true but R is false.
(D) A is false but R is true.
(a) Assertion: Urea is removed from the body through urine with the help of the
kidneys.
Reason: Urea is a waste product of animal.
Ans: (A) Both A and R are true and R is correct explanation of the assertion.
(b) Assertion: Greens plants are autotrophs.
Reason: Green plants prepare their food using the energy from the Sun.
ans: (A) Both A and R are true and R is correct explanation of the assertion.
5. Define the following:
(a) Life span
Ans: The period for which an organism remains alive, that is time from the
birth to the death is called the life span.
(b) Habitat
Ans: The place where an organism lives is called its habitat.
6. Answer in brief:
(a) What is stimulus? Give two examples of plant movements in response to
stimuli.
Ans:  Any change in the organism’s environment that causes it to react is
called a stimulus.
 Plants also show movement in response to stimuli such as light,
temperature and touch.
 The roots of plants always grow downwards towards soil and water
while the stem always grows upwards towards light.
 The stomata of the leaf open during the daytime and close at night.
(accept any two answers)
Theory type questions
(b) What is photosynthesis?
Ans: Plants use the energy from sunlight and make their own food using
water and carbon dioxide. This process of preparing food by green plants
is called photosynthesis.
7. Give reasons for the following:
(a) Plants have unlimited growth as compared to animals.
Ans: Plants grow throughout their life but animals stop growing after a
particular age. Thus, plants have unlimited growth whereas animals have
limited growth.
(b) Pigeons and crows are also known as diurnal animal.
Ans: Animals like crows, pigeons are active during the day time and are called
diurnal animals.
8.
(a) Identify the structure.
Ans: Stomata
(b) On which part of the plant this structure is present?
Ans: On the surface of the leaves.
(c) State the function of the structure.
Ans: Plants breathe through tiny pores called stomata present on the surface
of the leaves.
Picture based questions
9.
Ponds are small bodies of still, or not moving, fresh water that are surrounded
by land. Usually, we hear sounds of birds calling, crickets chirping, and frogs
croaking around the pond. We also see Lotus plants floating on the water, and
birds can be seen diving down to catch their next meal. We also see fish
swimming in the pond. Pond ecosystems are full of activity and life.
(a) List biotic factors listed in the paragraph above.
Ans: birds, frogs, crickets , lotus plant , fish
(b) List abiotic factors listed in the paragraph above.
Ans: Land, water.
https://study.com/academy/lesson/pond-ecosystem-lesson-for-kids.html
10.
Unscramble the words using clues given below:
(a) odcndreoab : carbon dioxide
Clue: Gas given out when fossil fuels are burnt in vehicles and factories.
(b) lsoi : soil
Clue: Forms the lithosphere of the earth
(c) enpslfia : lifespan
Clue: The period for which an organism remains alive.
(d) lucelamlritul : multicellular
Clue: Organism made up of many cells
11.
1. Why do leaves of desert plants become spines?
Ans: Due to high temperature water is lost from the leaves. To check water
loss, leaves of desert plants become spiny.

HOTS

. Why do leaves of desert plants become spines?
Ans: Due to high temperature water is lost from the leaves. To check water
loss, leaves of desert plants become spiny
Fun based questions
Paragraph based question