Required Practical 2

Question 1

Describe how temporary mounts of plant tissue are made

Answer 1

• Place root in hydrochloric acid
• Wash root in water
• Add stain
• Break up tissue with mounted needle
• Cover with coverslip and apply pressure

Question 2

Where in plants can cells undergoing mitosis be found?

Answer 2

Meristem tissue at shoot and root tips

Question 3

What is the mitotic index?

Answer 3

The ratio of cells undergoing mitosis to the total number of cells in a sample

Question 4

State the formula for mitotic index

Answer 4

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

Question 5

State the hazards and precautions for reagents used in this procedure

Answer 5

• HCl- corrosive, avoid contact with skin, wear eye protection
• Toluidine blue O stain- irritant, avoid contact with skin, wear eye protection
• Scalpel- cut away from fingers

Question 6

Describe how the scientist could have used the temporary mounts of leaves to determine the mean number of chloroplasts in mesophyll cells of a leaf

Answer 6

• Select random cells
• Count number of chloroplasts
• Divide number of chloroplasts by number of cells

Question 7

When the student was making their microscope slide, they were told to ensure they did not move the coverslip sideways. Explain why

Answer 7

To prevent cells from rolling on top of each other

Question 8

Mitosis is important in the life of an organism. Give two reasons why

Answer 8

• To increase number of cells
• Produce genetically identical cells