NCERT Class 11-Biology: Chapter – 7 Structural Organization in Animals Part 6 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 15:

Mention special features of eye in Cockroach.


The special features of eyes in cockroaches are:

(i) They have compound eyes i.e.. , it contains numerous small visual units.

(ii) It has about 2000 small visual unit in an eye which is known as ommatidia.

(iii) The ommatidia help the cockroach in receiving several images of a particular object. This kind of vision is known as mosaic vision.

(iv) The eyes of the cockroaches have more sensitivity but lower resolution.

(v) Cockroaches can see well during the night i.e.. , they have nocturnal vision.

Question 16:

Frog is a poikilotherm, exhibits camouflage and undergoes aestivation and hibernation, how are all these beneficial to it?


Since frog is a poikilotherm i.e.. , it is not able to maintain constant body temperature and its temperature is dependent on the environment. So, for its survival, it goes into an isolated place or buries itself in soil and hibernates during the low-temperature seasons (i.e.. , winter) and it goes into aestivation during the high-temperature seasons (i.e.. , summer) . Thus, during hibernation and aestivation, it sleeps and uses the stored energy in the body and emerges after the harsh environmental temperature has passed.

Camouflaging is very important for a frog because by the method of camouflaging it can blend itself to the surrounding place. It helps in getting protected from preys like snakes and eagles as they cannot see the camouflaged frog easily. It also helps the frog in catching its prey. Therefore, camouflage helps in the frog՚s protection and catching a prey.

Question 17:

Write the functions in brief in column B, appropriate to the structures given in column A.

Chapter 7 - Question 17 Table of the Structures Given in Column A
Column AColumn B
a.Nictitating membranei.________
c.Copulatory padiii.________


Column A Column B

a. Nictitating membrane

i. It is the third eyelid present in frogs which protects the frog from water and land environment and also helps in lubrication of the frog՚s eyes

b. Tympanum

ii. It is present behind the eyes of a frog. It helps in transmitting soundwaves to the inner part of the ear in frogs.

c. Copulatory pad

iii. The male frogs have a copulatory pad on the forelimbs which help in holding the female tightly during mating.

Question 18:

Write the appropriate type of tissues in column B according to the functions mentioned in column A.

Chapter 7 - Question 18 Table of Type of Tissues in Column B According to the Functions Mentioned in Column a Column A
Column AColumn B
a.Secretion and absorptioni.________
b.Protective coveringii.________
c.Linking and supporting frameworkiii.________


Column A Column B

a. Secretion and absorption

I. Cuboidal epithelium.

Explanation: These tissues are found in organs which are involved in secretion like the salivary glands, thyroid follicles, etc. They are also found in organs specialized in diffusion like the kidney tubules.

b. Protective covering

ii. Stratified epithelium.

Explanation: These tissues help in the protection of the dry skin. It has multi-layers and thus does not have much role in secretion. Stratified epithelial cells are found mainly in the parts of the body which experience mechanical, chemical, osmotic or thermal stresses.

c. Linking and supporting framework

iii. Connective tissue.


They are involved in the binding and connection of different tissues and organs and they help in providing structural rigidity, support, and protection of the body. They are also involved in the transport and exchange of various enzymes, hormones, gases and molecules such as nitrogenous wastes, vitamins, etc.

Question 19:

Using appropriate examples, differentiate between false and true body segmentation.


False Body Segmentation True Body Segmentation
False body SegmentationTrue body Segmentation
(i) Different segments are independent of each other(i) Different segments are interrelated.
(ii) Different segments do not work in coordination rather work independently(ii) Different segments work in coordination
(iii) Example: Tapeworm(iii) Example: Earthworm