Assignment for IX

Do this in your notebook

Q1 What is the difference between chromatin ,chromosome and gene?
A Chromatin is thread like material material made up of DNA in the shape of bunch
  Chromosome is single separate thread of DNA seen when the cell is about to divide .
Gene is a segment of DNA located in chromosome ,and responsible for controlling specific function in the cell.
.
Q2 What is the difference between nucleoid and nucleolus?
A Nucleoid  is the nuclear region in prokaryotic cell which has no surrounding membrane.
A nucleolus is a dot like structure present in nucleus ,it is made up of RNA and is responsible for Protein synthesis.

Q3  Name the following 
(1)kitchen of the cell
(2)Power house of the cell 
(3)Store house of the cell
(4)Suicidal bag
(5)Packaging material

A(1)Chloroplast
(2)Mitochondrion
(3)Vacoule
(4)Lysosome
(5)Golgi Apparatus

Q4  What is membrane biogenesis?
A Rough Endoplasmic reticulum makes proteins while smooth ER forms lipids ,both together helps in synthesis of new cell membrane ,this phenomenon is called membrane biogenesis

Q5 What is plasmolysis?
A when plant cell is immersed in hypertonic solution then it loses water and shrinks ,this state is called plasmolysis in plant cell.

Q6 What is Endocytosis?
A when unicellular organisms  like Amoeba engulf food through flexible cell membrane ,this process of taking food in is called endocytosis.

Q7 What is cell division ?
A It is a process by which one cell divides into two to pass on its information for growth and reproduction.
Q8 What is the difference between mitosis and meiosis?
A Mitosis is a division in which one cell divides into two daughter cells and both receive same number of chromosome Aas were there in the mother cell so they are similar to the parent cell .
This division helps in growth ,repair ,replacement of old cells and reproduction in unicellular organisms .
Meiosis is  the type of cell division in which new cell receive half number of chromosomes as were there in mother cell .This type of cell division occurs in reproductive cells and helps in reproduction .

Q9 Name the organanellae which can make their own proteins and why?
A Mitochondrion and plastids can make their own proteins as they have DNA and Ribosomes present in them.

Q10 Why is cell membrane called selectively permeable?
A Cell membrane allows only selective substances to pass through it therefore it is called selectively permeable membrane.A
A