AP 7th Class Science 2nd Lesson Questions and Answers Nutrition in Animals

Access to the AP 7th Class Science Study Material 2nd Lesson Nutrition in Animals Questions and Answers are aligned with the curriculum standards.

AP 7th Class Science 2nd Lesson Nutrition in Animals Questions and Answers

AP Board Solutions Class 7 Science Chapter 2 Nutrition in Animals

Exercise 

1. Fill in the blanks:

a) The main steps of nutrition in humans are ………… , ………… , ………… , ………… and …………
b) The largest gland in the human body is …………
c) The stomach releases hydrochloric acid and ………… juices which act on food.
d) The inner wall of the small intestine has many finger-like out growths called …………
e) Amoeba digests its food in the …………
Answer:
a) Ingestion, digestion, absorption, assimilation and digestion.
b) Liver
c) Digestion
d) Villi
e) Food Vacuole

2. Mark ‘T’ if the statement is true and ‘F’ if it is false :

a) Digestion of starch starts in the stomach. (T/F)
b) The tongue helps in mixing food with saliva. (T/F)
c) The gall bladder temporarily stores bile. (T/F)
d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)
Answer:
a) False
b) True
c) True
d) True

Question 3.
Tick (✓) mark the correct answer in each of the following :
a) Fat is completely digested in the
i) stomach
ii) mouth
iii) small intestine
iv) large intestine
Answer:
iii) small intestine

b) Water from the undigested food is absorbed mainly in the
i) stomach
ii) foodpipe
iii) small intestine
iv) large intestine
Answer:
iv) large intestine.

Question 4.
Match the items of Column I with those given in Column II :
Column I — Column II
Food components — Product(s) of digestion
Carbohydrates — Fatty acids and glycerol
Proteins — Sugar
Fats — Amino acids
Answer:
Column I — Column II
Food components Product(s) of digestion
Carbohydrates — Sugar
Proteins — Amino acids
Fats — Fatty acids and glycerol

Question 5.
What are villi? What is their location and function?
Answer:

• The finger like projections in the inner walls of the small intestine is called Villi.
• These are found in small intestine.
• The main function of Villi is to increase the surface are for absorption of the digested food.

Question 6.
Where is the bile produced? Which component of the food does it help to digest?
Answer:

• Bile is produced in liver.
• The bile juice is stored in a sac called the gall bladder.
• It helps in the digestion of fats.

Question 7.
Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Answer:

• Cellulose is the carbohydrate that can be digested by ruminants.
• Ruminants have large sac like structure between the small intestine and large intestine.
• The cellulose of the food is digested by the action of certain bacteria which are not present in humans.

Question 8.
Why do we get instant energy from glucose ?
Answer:

• Because it easily breaks down in the cell with the help of oxygen which provides instant energy in the organism.
• Glucose does not need digestion, it is directly absorbed into the blood.

Question 9.
Which part of the digestive canal is involved in :
i) absorption of food …………
ii) chewing of food …………
iii) killing of bacteria …………
iv) complete digestion of food …………
v) formation of faeces …………
Answer:
i) Small intestine
ii) Mouth
iii) Stomach
iv) Small intestine
v) Large intestine

Question 10.
Write one similarity and one difference between the nutrition in amoeba and human beings.
Answer:
Similarity :

• The digestive juices in amoeba are secreted into food vacuole and in human beings the digestive juices are secreted in stomach and small intestine.
• Then the juices convert complex food into simpler soluble and absorbable substances.

Difference: Amoeba captures the food with the help of pseudopodia and engulf it. In human beings food is taken by the mouth.

Question 11.
Match the items of column I with suitable items in column II :

Column I	Column I
a) Salivary gland	i) Bile juice secretion
b) Stomach	ii) Storage of undigested food
c) Liver	iii) Saliva secretion
d) Rectum	iv) Acid release
e) Small intestine	v) Digestion is completed
f) Large intestine	vi) Absorption of water
	vii) Release of faces

Answer:

Column I	Column I
a) Salivary gland	iii) Saliva secretion
b) Stomach	iv) Acid release
c) Liver	i) Bile juice secretion
d) Rectum	ii) Storage of undigested food
e) Small intestine	v) Digestion is completed
f) Large intestine	vi) Absorption of water

Question 12.
Label Figure of the digestive system.

Answer:

Question 13.
Can we survive only on raw, leafy vegetables/grass? Discuss.
Answer:

• As we know that the animals, fungi, bacteria, non-green plants and human beings do not have the ability to make their own food.
• They depend upon autotrophs for their food directly or indirectly.
• Humans cannot survive only on raw, leafy vegetables or grass.
• It is because the grass is rich in cellulose, which is a type of carbohydrate that humans are not able to digest due to the absence of cellulose – digesting enzymes.

Questions given in the lesson

Page No. 24

Question 1.
Have you ever wondered what happens to the food inside the body?
Answer:
The food passes through a continuous canal which begins at the buccal cavity and ends at the anus.

Page No. 26

Question 2.
Boojho is fascinated by the highly coiled small intestine seen in Figure. He wants to know its length. Would you like to make a wild guess? Can you imagine how such a long structure is accommodated in a small space within our body !
Answer:
The small intestine of humans is approximately 7.5 meter. The highly coiled nature of the small intestine makes it possible to fit in the lower abdomen.

Page No. 36

Question 3.
Paheli wants to know why these animals (ruminants) cannot chew food properly at the time they take it in ?
Answer:
The ruminants mainly feed on grass and bush which primarily contain cellulose or roughage. So, they store the food in part of a stomach called rumen where it is partially digested and is called cud. After the partial digestion of cellulose, it is brought back to the mouth and chewed properly.

Question 4.
Boojho wants to know why we cannot digest cellulose like the cattle do?
Answer:
Humans cannot digest cellulose in their food like cattle due to the absence of a large sac – like structure called ‘caecum’. The cellulose of the food is digested by the action of certain bacteria which are not present in humans.

Extended Learning – Activities and Projects

Question 1.
Visit a doctor and find out:
i) Under what conditions does a patient need to be on a drip of glucose?
ii) Till when does a patient need to be given glucose?
iii) How does glucose help the patient recover?
Write the answers in your notebook.
Answer:
i) A patient should be given glucose drip when he is dehydrated. Glucose drip is also given when the patient is unable to take his food.
ii) A patient is usually administered glucose through drip until their blood glucose level reaches normal level and maintain consistancy.
iii) Glucose is the simplest form of carbohydrates that is directly poured into the blood and absorbed by the cells of the body.
It provides instant energy to all the organs of the body to perform their functions. In this way, glucose helps the patient recover fast.

Question 2.
Find out what vitamins are and get the following information.
i) Why are vitamins necessary in the diet?
ii) Which fruits or vegetables should be eaten regularly to get vitamins?
Write a one-page note on the information collected by you. You may take help of a doctor, a dietician, your teacher or any other person, or from any other source.
Answer:
i)

• Vitamins are organic substances that can be found in natural foods and are necessary for the body’s regular development and maintenarice.
• The body uses vitamins for a number of vital processess including cellular growth and differentiation, enhancement of immune system, wound healing and antioxidant protection.

ii)

• Food products such as leafy vegetables and fruits are the best source of water soluble vitamins.
• Major food ingredients rich in vitamins include seeds, broccoli, mango, papaya, citrus fruits, nuts, sweet bell peppers, apples, banana, avocados, peas and berries.

A note on Vitamins :
Vitamins : Vitamins are of two basic types.

• Fat soluble vitamins : A,D, E, K
• Water soluble vitamins: C, B complex

Vitamins are available from milk, bran of cereals, citrus fruits, sprouts, sun- light, vegetables, liver oils etc.
Some vitamin deficiency diseases are

• Vitamin A – Night blindness, dry eyes
• Vitamin B – Beri beri, pellagra, scaly skin
• Vitamin C – Scurvy
• Vitamin D – Rickets
• Vitamin E – Fertility disorder
• Vitamin K – Delay in clotting of blood

Question 3.
Collect data from your friends, neighbours and classmates to know more about “milk teeth”.
Tabulate your data. One way of doing it is given below :

S. No.	Age at which first tooth fell	Age at which last tooth fell	No. of teeth lost	No. of teeth replaced
1.
2.
3. .
4.
5.

Find out from at least twenty children and find the average age at which children lose the milk teeth. You may take help of your friends.
Answer:
Hint: The average age at which children lose milk teeth is between 6-8 years.

S. No.	Age at which first tooth fell	Age at which last tooth fell	No. of teeth lost	No. of teeth replaced
1)	6 years	10 years	20	30
2)	6 years	11 years	20	28
3)	7 years	12 years	20	28
4)	8 years	13 years	20	32
5)	8 years	12 years	20	28

Activities

Activity 2.1 Page No : 22

Question 1.
What is the type of food and mode of feeding of the following animals ? Write down your observations in the given table. You may find the list of modes of feeding given below the table helpful.
Various modes of feeding

Name of animal	Kind of food	Mode of feeding
Snail
Ant
Eagle
Humming – bird
Lice
Mosquito
Butterfly
Housefly

(Scraping, chewing, siphoning, capturing and swallowing, sponging, sucking etc.)
Answer:
Various modes of feeding

Name of animal	Kind of food	Mode of feeding
Snail	Leaves, fungi, algae insects	Scraping
Ant	Insects, sugar, rice, wheat flour	Chewing
Eagle	Meat of animals and birds	Capturing and swallowing
Humming-bird	Nector	Sucking
Lice	Blood	Sucking
Mosquito	Blood	Biting and Sucking
Butterfly	Nector	Siphoning
Housefly	Semi digested food	Sponge

(Scraping, chewing, siphoning, capturing and swallowing, sponging, sucking etc.)

Activity 2.2 Page No: 26

Question 2.
Write an activity to observe different types of teeth present in your mouth?
Answer:

• Wash your hands. Look into the mirror and count your teeth.)
• Use your index finger to feel the teeth.
• How many kinds of teeth could you find? a.
• Take a piece of an apple or bread and eat it.
• Which teeth do you use for biting and cutting and which ones for piercing and tearing. Also find out that are useful for grinding and chewing.

Observations:

• We have four types of teeth. They are molar, premolar, canine and incisor.
• To bite apple or bread we cut them using our incisors.
• For piercing and tearing we have pointed teeth that are canines.
• We have two types of teeth for grinding and chewing. They are molars and premolars.

My observations are recorded in the following table.

Type of teeth	Number of teeth		Total
	Lower jaw	Upper jaw
Cutting and biting teeth	4	4	8
Piercing and tearing teeth	2	2	4
Chewing and grinding teeth	10	10	20

Question 3.
Write an experiment to show the effect of saliva on starch.
Answer:
1. Take two test tubes. Label them ‘A’ and ‘B’.
2. In test tube ‘A’ put one teaspoonful of boiled rice, in test tube ‘B’ keep one teaspoon full of boiled rice after chewing it for 3 – 5 minutes.
3. Add 3 – 4 ml of water in both the test tubes.
4. Now, pour 2-3 drops of iodine solution 9 in each test tube and observe.

Observations: A Boiled arid chewed lice

• Saliva treated rice (chewed boiled rice) does not turn blue with iodine solution.
• However, plain boiled rice (test tube A) turns blue with iodine.

Reason : Our saliva contains an enzyme amylase. The enzymatic reaction between starch and salivary amylase breaks starch and other complex carbohydrates into simple sugars. Sugar does not form a complex with iodine solution. As a result, chewed rice does not turn blue.

Activity 2.4 Page No : 30

Question 4.
Write an activity to identify the position of taste buds on different regions of tongue.
Answer:
1. Prepare a separate sample each of

• sugar solution,
• common salt solution,
• lemon juice and
• juice of crushed neem leaf or bitter gourd.

2. Blind fold one of your classmates and ask her/him to take out the tongue and keep it in straight and flat position.
3. Use a clean toothpick to put the above samples one by one on different areas of the tongue as shown in the adjacent figure. Use a new toothpick for each sample.
4. Ask the classmate which areas of the tongue could detect the sweet, salty, sour and bitter substances.

Observations:

• Every flavour has a specific location for their taste.
• Tip of the tongue makes us feel sweet while the back of tongue makes us aware of bitter; sides give us the feeling of salty and sour.
• If we use different flavour at another location, we do not feel the taste.