Cell Specialisation

Question 1

Function of sperm cell:

Answer 1

• To fertilise a female egg cell
• Contains half a set of chromosomes and passes
these onto offspring

Question 2

Adaptations of sperm cells:

Answer 2

• The sperm cell has a long tail (flagellum) which produces a swimming movement
• The sperm head (acrosome) has enzymes which breakdown a small part of the egg cell membrane to allow the head
to enter with its chromosomes
• Have many mitochondria which release E through aerobic respiration, this is needed to allow the sperm to have enough E to swim to the egg and fertilise it

Question 3

Function of nerve cells/ neurons:

Answer 3

To quickly send and receive electrical messages to and from the brain and nervous system

Question 4

Adaptations of nerve cells:

Answer 4

• Has a long, thin shape which allows impulses to travel long distances in the body and makes it faster to send
electrical messages
• Its axon is covered in rings of myelin sheath
• The myelin sheath stops the electrical signals from travelling down the axon because it is an electrical insulator
• This means the electrical signals have to jump between gaps of the myelin sheath, speeds up the conduction of electrical impulses and allows them to travel much faster

Question 5

Function of muscle cells:

Answer 5

• To control all the muscles in the body by contracting and relaxing
• When it contracts it gets shorter and when it relaxes it gets longer

Question 6

Adaptations of muscle cells:

Answer 6

• Have many mitochondria which release E through
aerobic respiration as muscle cells make up all the muscles in the body and need a lot of E
• Elongated
• Can contract

Question 7

Function of root hair cells:

Answer 7

• Efficient uptake of water and mineral ions
• Root hair cells absorb water by osmosis
• Root hair cells absorb minerals (nitrate ions) by active transport

Question 8

Adaptations of root hair cells:

Answer 8

• Large surface area with a projection/root hair - large SA
for diffusion
• Thin cellulose walls - short
diffusion pathway
• Many mitochondria for aerobic
respiration - releases a lot of E
for active transport
• Adapted for efficient uptake of water by osmosis, and mineral
ions by active transport
• Large vacuole - for temporarily
storing water before it is
transported up through the
cell

Question 9

Function of phloem cells:

Answer 9

Phloem tissue transports dissolved sugars and amino acids from the leaves to the rest of the plant for immediate use or storage - this
movement of food molecules through phloem tissue is called translocation

Question 10

Adaptations of phloem cells:

Answer 10

• Composed of tubes and elongated cells, made of living cells lined end to end, found in the vascular bundle

• The cell walls between phloem cells break down to form perforated sieve plates

• These allow water carrying dissolved food (sugars and amino acids) to move freely
along the tubes from one phloem cell to the next through pores in the end walls

Question 11

Functions of xylem cells:

Answer 11

Xylem tissue transports water and mineral ions from the roots to the stems and leaves in the transpiration stream - process called transpiration

Question 12

Adaptations of xylem cells:

Answer 12

• Mature xylem consists of elongated dead, hollow cells arranged end to end to form continuous hollow vessels
(tubes)
• Mature xylem vessels contain no cytoplasm
• Have tough walls containing a woody material called lignin that builds up in spirals in cell walls. Lignin makes spirals verystrong, to withstand the pressure from the water + provide support. - adapted for
transport of water in transpiration stream
• The contents and end walls break down to form a hollow centre (lumen) - reduces resistance during transpiration
and allows more efficient
transport of water and mineral ions