Cell biology - specialisation and differentiation

Question 1

what is differentiation

Answer 1

the process by which a cell changes to become specialised for its job

Question 2

what happens to cells as they change

Answer 2

they develop different subcellular structures and turn into different types of cells, allowing them to carry out specific functions

Question 3

how are nerve cells specialised to do its job

Answer 3

• job is to carry electrical signals from one part of the body to another
• long axon to increase the distance the cell travels
• dendrites to connect to other nerve cells and pass signals
• The nerve cell is covered with a fatty sheath, which stops nerve signals from leaking out and speeds up the transmission (travel) of electrical signals

Question 4

how are sperm cells specialised to do their job

Answer 4

• job is to get the male dna to the female dna and fertilise the egg
• long tail ( flagellum) and streamlined head to swim to egg
• carries enzymes in the head to digest through the egg cell membrane
• contain a lot of mitochondria to give the cell energy
• streamlined head to aid swimming

Question 5

how are muscle cells specialised to do their job

Answer 5

• job is to contract quickly
• a lot of mitochondria to generate energy for motion
• the cells are long so they have space to contract
• protein fibres contract, allowing muscle cells to move

Question 6

how are root hair cells specialised to do their job

Answer 6

• job is to take up substances from the soil
• long projections, large surface area for absorbing water and mineral ions from the soil
• thin walls so that movement of water is not restricted
• no chloroplasts as it’s underground

Question 7

how are xylem cells specialised to do their job

Answer 7

• job is to transport substances
• no top and bottom walls, so there is a continuous column of water running through them
• walls become thickened and woody. They therefore support the plant
• Lignin strengthens the walls of xylem cells

Question 8

how are phloem cells specialised to do their job

Answer 8

• job is to transport dissolved sugars and amino acids
• ## end walls of phloem cells contain small holes to allow food products to move up and down the phloem vessels throughout the plant.

Question 9

why can’t all body cells be used to grow different types of cells

Answer 9

because body cells that have already differentiated are not capable changing into any other types of cell