Short Answer Questions on cell structure and function for class 8
What is a tissue?
A group of similar cells that perform a particular function is called tissue. For e.g. muscles cells make up the muscular tissue.
What are genes? Write their function?
Genes are the segment of DNA. Genes are units of inheritance i.e. they help in transmitting characters from parents to offsprings.
Why is the cell wall present in plant cells and not in animal cells?
The plants do not have a skeleton for support and protection, nor can they move to escape environmental stress so they need a cell wall as a protective layer around them which is not at all needed by animal cells.
Write the function of vacuole in animal cells?
In animal cells, vacuoles are smaller and may be greater in number. They help in waste removal and digestion.
Write the difference between cytoplasm and nucleoplasm?
The jelly-like substance inside the cell in which nucleus and cell organelles are present is called cytoplasm whereas the liquid or dense material inside the nucleus is called nucleoplasm.
Why is a cell membrane important to a cell?
Cell membrane is important to a cell because it regulates the entry and exit of substances in the cell and it protect the cell and gives it a shape.
What is cell division and why it is necessary?
New cells for growth and repair are formed by cell division. Cell division is also necessary for replacement of dead cells.
What are dictyosomes?
In plant cells, golgi bodies are not well defined and are called dictyosomes.
What is microscope?
It is a instrument used for viewing objects that are too small to be seen with the naked eye.
Write the function of nucleolus?
A smaller spherical structure present inside the nucleus, called Nucleolus plays an important role in protein synthesis.