Paper 1 - Tissue Culture

Question 1

What is tissue culture ?

Answer 1

• Growing of cells / tissues in a liquid agar (containing nutrients or a solid medium)
• this grows identical cells quickly creating an undifferentiated clump of cells called a callus.
• cells treated with hormones to become differentiated into specialised cells.

Question 2

Tissue culture example in humans

Answer 2

• Beyene in 2011 recieved the first transplant of a tissue- engineered synthetic organ.
• new part of windpipe made from unreactive material and coated in stem cells from his own bone marrow. -> new epithelial cells would form around the structure and his immune system would not reject the organ

Question 3

Why do we use tissue culture in plants?

Answer 3

Used to produce :

• New plants of rare species on the brink of extinction.
• new individuals of plant species that may be hard to grow from seed.
• clones of GM plants

Question 4

How do we preform tissue culture In plants ?

Answer 4

Peice of plant dipped in bleach solution to sterilise it
Route 1 ■ peice of plant cut off and placed into the sterile nutrient medium to grow. Piece treated with hormones so it grows roots and shoots. When plants large enough they are planted in the soil or compost
Route 2 ■ sometimes only a few cells are cut off, and placed into a sterile nutrient medium to form a callus. Callus treated with hormones so that plantlets develop roots and shoots. Plantlets separated and grown on nutrient medium In sterile conditions, until large enough to grow and can be planted in soil or compost.

Question 5

Plant culture - uses in medicine

Answer 5

Culturing a thin layer of cells onto agar means we can :

• study how cells communicate with each other
• study viruses which cannot replicate outside of cells
• culture cancer cells to see how cancers spread and develop.
• investigate how infected cells respond to new medicines without risk to living organisms.

Question 6

Tissue culture - hope for the future

Answer 6

Cultures of cells CAN be developed into tissues - still need a supporting structure, not yet possible to produce fully functioning organ.
Similar process used to create artificial bladders