NCERT Solutions for Class 8th Science
Chapter 8. Cell - Structure and functions
Text Book Exercise
Q1. Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)
Answer : (a) (T), (b) (F), (c) (F), (d) (T).
Q2. Make a sketch of the human nerve cell. What function do nerve cells perform?.
Answer : The nerve cell receives and transfers messages, therby helping to control and coordinate the working of different parts of the body.
Q3. Write short notes on the following:
(a) Cytoplasm (b) Nucleus of a cell
Answer : (i) Cytoplasm : it is the jelly-like substance fou nd in between the nucleus and the cell membrane. It contains nucleus and many small structures called organelles. Cytoplasm, along with nucleoplasm, forms the living substance of the cell, called the protoplasm.
(ii) Nucleus : It is an important components of the living cell. It is generally spherical and located in the centre of the cell. It can be stained and seen easily with the help of a microscope. Nucleus is separted form the cytoplasm by a membrane called the nuclesr membrane. the liquid substance of the nucleus is termed as nucleoplasm.