NCERT solutions for class 8 science is an extremely essential study tool for the CBSE students studying in class 8. NCERT class 8 science solutions in PDF format as well which are free to download and students can have access to these NCERT solutions.
CBSE NCERT Solutions for Class 8 Science Chapter 8:
Write short notes on the following.
(a) Cytoplasm: It is a fluid that fills the cell and is present between the plasma
membrane and the nucleus. Cell organelles such as mitochondria, ribosomes, Golgi
bodies, etc. are suspended in the cytoplasm. The cytoplasm helps in the exchange of
materials between cell organelles. It also serve as site for all metabolic activities
(b) Nucleus of a cell: Nucleus is the master of the cell. It commands all the functioning of the cell. It is generally located in the center of the cell and is spherical in shape. A membrane called nuclear membrane separates it from cytoplasm. It contains the genetic material DNA and RNA in it. This porous membrane allows the transfer of material in the nucleus and cytoplasm. Nucleus contains a dense body called Nucleolus which actually contains chromosomes, the genetic material.
Cells are the basic structural units of living organisms. Explain.
In Biology, the basic unit of which all living things are composed is known as
‘cell’. The ‘cell’ is the smallest structural unit of living matter that is capable of functioning independently. A single cell can be a complete organism in itself, as in bacteria and protozoans. A unicellular organism also captures and digests food, respires, excretes, grows, and reproduces. Similar functions in multi-cellular organisms are carried out by groups of specialized cells which are organized into tissues and organs such as, the higher plants and animals. Hence, ‘cell’ is known as the basic structural and functional unit of life.
Explain why chloroplasts are found only in plant cells?
Plants are the autotrophs that make their own food through the process of
photosynthesis in presence of sunlight. Chloroplasts are found only in plant cells because they are required for photosynthesis. The have the green pigment called chlorophyll that trap the sunlight for photosynthesis.