mitosis practical Flashcards

(8 cards)

1
Q

detailed method

A
  • cut off root tip off onion/garlic and add to beaker of 10ml hydrochloric acid
  • leave in for 10 mins
  • rinse the root tip in distilled water
  • place specimen on microscope slide
  • cover specimen with toluidene bleu stain and macerate with mounted needle to separate cells
  • add cover slip and spread material gently
  • look through microscope
  • chromosomes should stain dark blue
  • take a photo of sample
  • calculate mitotic index
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2
Q

why are you told to observe cells that are found at or just behind the root tip called the meristem

A

most ideal area to look for mitosis, meristem cells are undifferentiated, and constantly dividing, making them ideal to observe.
cells in meristem are totipotent

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3
Q

explain why cells may appear elongated with no visible chromosomes if they are taken too far along the root

A

in the region of cell elongation, they are increasing in size but not dividing

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4
Q

why use HCL

A

-HCL quickly denatured any protein including enzymes
- it quickly stops cellular processes
- kills cells halting the process immediately so the cells in different stages can be seen

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5
Q

why use toluidine blue

A

Dye is used for staining of acid rich tissues
As it can be absorbed by nucleic acid
- it increases contrast
- makes chromosomes visible

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6
Q

why is it necessary to spread the material on the slide

A

cells could overlap each other
stain might not have been dispersed properly

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7
Q

why is it suggested to look at several fields of view

A

-comparison
-mean of mitotic index

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8
Q

what does diploid number of 16 mean

A

-8 chromosomes from male
-8 from female

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