Mitosis root tip squash

Question 1

What equipment do we need?

Answer 1

= hydrochloric acid- soften and loosen root tissues
= acetin orcein stain- turns chromosomes a purple-red colour
= mounted needle- to lower cover slip and prevent air bubbles under the slip
root tip; this is where mitosis should be occuring

Question 2

What is the method?

Answer 2

= grow garlic ontop of a beaker of water for 3 days- new roots in the dark
= cut of the tip of the root 5mm from the end this is where mitosis is occurinb

Question 3

What is the next step?

Answer 3

= place root tip in a tets tube of hcl and leave in water bath for 60 degrees
= leave for 10 mins so acid can soften the cells
= pour acid out of test tube and place root tip on a watch glass rinse with distilled water
= place root tip on microscopic slide then use filter paper to excess water

Question 4

What is the next step?

Answer 4

=add two drops of indiacator
= use mounted needle to lower cover slip and leave for 10 mins- stains chromosomes
= place filter paper on top and push down make sure it does not slip or move the coverslip spreads the cell into a single layer so light can pass through

Question 5

How do we calculate the mitotic index?

Answer 5

= the number of cells in mitosis/ total number of cells x 100

Question 6

What is the hazard of a scalpel?

Answer 6

= risk of cutting yourself
= control: keep away from fingers

Question 7

What is the hazard of hcl?

Answer 7

= causes irritation to eyes and previous injuries
= wear eye protection, tie up long hair, avoid contact with skin

Question 8

What is the risk of the stain?

Answer 8

= causes irritation
= wear eye protection, tie up long hair, avoid skin

Question 9

What is the risk of broken glass?

Answer 9

= risk of cutting yourself
= take care when handling

Question 10

When counting the cells to calculate the mitotic index what should you do to make sure this is accurate?

Answer 10

= examine large field of cells/large number of cells
= ensure a represenative sample

Question 11

What does the eye peice graticule do?

Answer 11

= used to measure the size of the object,
= each time you change the ibjective lense, and magnification, you have ti calibrate

Question 12

What does a stage micrometer do?

Answer 12

= used to calibrate the eye peice graticule
= glass slide with a scale with it, this is usually 2mm apart and and the sub divisions are 10 micrometrees apart

Question 13

How do we calibrate this?

Answer 13

= lie up the stage micrometer and eye peice graticule whulst lookimg through the eye peice
= count how many divsions, on the eye peice graticule fit in one divisiom, on the micrometer scale
= each divison on the micrometer is 10um so this can be used to calulate what one divison is at the current magnification