NCERT Solutions Basic Unit of Life

Question 1
Name any two of the several important functions of the proteins embedded in the plasma membrane.
(i) They perform functions vitals to the survivals of organisms.
(ii) Proteins relay signals between the cell’s internal and external environment.

Question 2
What are the function of pores present in nuclear membrane?
Nuclear pores are formed by the fusion of inner and outer nuclear membrane. They help in the exchange of substance between nucleus and cytoplasm.

Question 3
Differentiate between sensory and motor nerve.
Sensory nerve and motor nerve
A sensory nerve is a nerve that carries information towards central nervous system. It is an enclosed cable like bundle of afferent nerve fibres.
Motor nerves are efferent nerve fibres that carry signals from CNS to effectors to produce effects.

Question 4
What purpose does cuticle serve?
Cuticle helps to reduce water loss by evaporation. The primary function of plant cuticle is as a water permeability barrier that prevents evaporation of water from epidermal surface and also prevents external water and solutes from entering tissues.

Question 5
What do you understand by term Biodiversity hotspots give example?
Biodiversity hotspots is a biogeographic region that is both a significant reservoir of biodiversity and is threatened within destruction.
Eg-Himalayas, western ghate etc.

Question 6
How Embryonic stem cell differ from adult stem cell

Embryonic stem cell
Adult Stem Cell
They are pluripotent
They are multipotent
Embryonic stem cell are found in 3 germ layers of embryo

Various type of stem cell are studied in embryo
They are found in differentiated tissues but remain undifferentiated

stem cell in bone marrow are most studied type of cell.

Question 7
where do you find ciliated epithelium in human body?
Fallopian tube, respiratory tract, uterus etc.

Question 8
What do you mean by glycosylation? Give example.
The addition of carbohydrate mocity to the protein which is then carried by cisternae of Golgi apparatus is called glycosylation

Question 9
Give two characteristics of stem cell.
Characteristics of stem cell are as follows :-
(1) They are capable of dividing and renewing themselves for a long period.
(2) They are unspecialized and have the ability to differentiate into specialized cell through asymmetric division.

Question 10
Differentiate between totipotent and pluripotent stem cells.

totipotent stem cell can differentiate into all the cell type Example-zygote
Pluripotent stem cell can differentiate into many cell types but not all. Examples-placenta

Question 11
What man made changes are responsible for deterioration of biodiversity on earth?
The man-made changes responsible for loss of biodiversity are –
(1) Pollution
(2) Deforestation
(3) Construction of large dams

Question 12
Define ecosystem.
Ecosystem is a biological community of interacting organisms and their physical environment.