Required Practical 2

Question 1

Why is the tip of the root used

Answer 1

Meristematic cells are found here

As cells are actively undergoing mitosis here

Question 2

How would you prepare a root time squash ?

Answer 2

Place coverslip and press down firmly but gently

Produces single layer of cells and allows light to passthrough

Question 3

What are the hazardous and precautions needed

Answer 3

Glass of coverslip can break easily
Do not let coverslip move from side to side
May damage or break the chromosomes

Question 4

What is the formula for mitotic index

Answer 4

Number of cells with visible chromosomes/ number of cells in sample

Question 5

How do you calculate the period of time spent at each stage

Answer 5

Eg 1 cell cycle takes 8 hours
50 cells, 4 in metaphase

1) convert hours to minutes =480 minutes
Time spent in metaphase is 4/50 x 480= 34.8

Question 6

Why does the student add a drop of stain

Answer 6

The stain binds to the chromosomes making them visible