1. Cell Biology (cell specialisation)

Question 1

What are
specialised cells?

Answer 1

Cells which are structured/specialised in a particular way to perform a specific function

Question 2

What is the function of root hair cells?

Answer 2

absorbing water and mineral ions

Question 3

What is the function of nerve cells?

Answer 3

to carry electrical signals from one part of the body to another

Question 4

What type of cell are sperm and egg cells?

Answer 4

Gametes (sex cells)

Question 5

What is the function of the Phloem?

Answer 5

Transports glucose from the leaves of the plant to the rest of the plant, excess glucose is stored in the roots as starch

Question 6

What is the function of
the Xylem?

Answer 6

To transport water + minerals + ions from the roots of the plant to the leaves

Question 7

What is the function of muscle cells?

Answer 7

To contract quickly

Question 8

What is the function of the sperm cell?

Answer 8

To get the male DNA to the female DNA

Question 9

What are the phloem and xylem cells specialised for?

Answer 9

transporting substances

Question 10

What is the function of an egg cell?

Answer 10

to carry the female DNA to nourish the developing embryo in the early stages

Question 11

How is a sperm cell specialised for reproduction?

Answer 11

• Acrosome- releases enzymes so it can digest the egg cell membrane
• The middle of the cell is packed with mitochondria to provide energy for the sperm to swim to the egg cell
• Flagellum - allows the sperm cell to actually swim to the egg cell to fertilise it
• Streamlined head - so it can travel to the egg faster because there is less drag

Question 12

How are root hair cells adapted for absorbing water and mineral ions?

Answer 12

• long hair like extension - to increases the surface area for absorbtion
• Many mitochondria - to release lots of energy for active transport of minerals +ions
• Large vacuole - for water to move into via osmosis
• No chloroplasts - because no light energy, so photosynthesis can’t occur

Question 13

How are nerve cells adapted for rapid signalling?

Answer 13

• Lots of dendrites - in order to connect with multiple cells at the same time
• Mylein Sheaths - insulate the cell so electrical impulses cannot pass through, and instead have to jump, causing electrical impulses to be transmitted faster
• Long - to cover more distance

Question 14

How are muscle cells adapted for contraction?

Answer 14

• All muscle cells are linked allowing them to contract in unison
• Lots of mitochondria - to generate and release the energy needed for contraction
• Many ribsomes - allows proteinsynthesis to occur, used to make protein fillaments
• Long - so that they have space to contract

Question 15

What are protein fillaments in muscle cells?

Answer 15

Fillaments on the cell, that slide over each other, causing muscle contraction

Question 16

How is the xylem adapted for transporting substances?

Answer 16

• Hollow tubes - maximizes the amount of water, minerals and ions travelling through the cell
• Strengthened by lignin

Question 17

How is the Phloem adapted for transporting substances?

Answer 17

• Companion cells - contains lots of mitochondria to provide energy for active transport of glucose
• Very few subcellular structures - so that glucose can flow through them
• Sieve plates - allows dissolved sugars to flow freely

Question 18

What is transpiration?

Answer 18

the loss of water from the leaves via evaporation - xylem

Question 19

What is translocation?

Answer 19

the movement of sugars - phloem

Question 20

How is the egg cell specialised?

Answer 20

it contains huge food reserves to feed the embryo