Specialised Cells

Question 1

How does a cell structurally adapt ?

Answer 1

The shape of the cell
The organelles the cell contains (or doesn’t contain)

Question 2

How is a microvilli adapted?

Answer 2

cell membrane projections that increase the surface area for absorption

Question 3

What are cilia made from?

Answer 3

hair-like projections made from microtubules

Question 4

What is cilia function?

Answer 4

Allows the movement of substances over the cell surface

Question 5

What are microtubules contain?

Answer 5

Made of a protein dimer - alpha & beta tubulin → dimers join to form a protofilament → many protofilaments form a microtubule

Question 6

What do microtubules make up?

Answer 6

make up the cytoskeleton of a cell - essentially a road network within cells - provides support and allows movement within the cell

Question 7

What are Flagella made from?

Answer 7

Similar in structure to cilia, but made of longer microtubules

Question 8

Function of Flagella

Answer 8

contract to provide cell movement

Question 9

Function of Nerve cells

Answer 9

Conduction of nerve impulses

Question 10

Structure of Nerve Cells

Answer 10

Cell body, Extended cytoplasm, insulated axon

Question 11

Adaption of nerve cells

Answer 11

Cell body is where most of the proteins are synthesised
Extended cytoplasm forms dendrites (receives signals) & axons (transmit signals) → Neurons are able to communicate with each other, muscles and glands
Axon is insulated with a fatty sheath → speeds up nerve impulse transmission

Question 12

What are the three types of muscle cell?

Answer 12

skeletal, smooth & cardiac (heart)

Question 13

What is the function of muscle cells?

Answer 13

muscle contraction e.g., movement

Question 14

What is the structure of muscle cells?

Answer 14

Contain layers of protein filaments, many mitochondria

Question 15

What are the adaptions of a muscle cell?

Answer 15

The protein filaments can slide over each other → causes muscle contraction
Lots of mitochondria - provides energy for contraction

Question 16

What is a sperm cells function?

Answer 16

Fertilisation (pass on fathers genes)

Question 17

Structure of sperm cell?

Answer 17

Nucleus in head, acrosome (containing digestive enzymes), many mitochondria in midpiece, tail

Question 18

What adaption does a sperm cell have?

Answer 18

Head contains paternal DNA →
uses with maternal DNA within the egg
Head also contains acrosomes → breaks down the outer layer of the egg cell → nucleus can enter
Lots of mitochondria - provides energy to propel the sperm
Tail - rotates to propel the sperm forwards, towards the egg cell

Question 19

Function of root hair cell

Answer 19

Absorb water & mineral ions from soil

Question 20

Structure of root hair cell

Answer 20

Structure: Extended cytoplasm, thinner walls, permanent vacuole, lots of mitochondria, no chloroplasts

Question 21

Adaptions of a root hair cell

Answer 21

Adaption:
Extended cytoplasm (root hair) increases the surface area → more water & ions absorbed
Thinner walls - water can move through easily
Permanent vacuole - contains cell sap & regulates the water potential gradient
Mitochondria - for active transport of mineral ions

Question 22

Xylems function

Answer 22

Transport tissue for water and dissolved ions

Question 23

Xylem Structure

Answer 23

Cells are dead (no cytoplasm & other organelles), no top & bottom walls, thickened outer walls (lignin)

Question 24

Xylem Adaption

Answer 24

No top or bottom walls - forms a hollow, continuous tube
Cells are dead & empty - allows free passage of water
Lignin - strengthens the tube & supports the stems of the plant

Question 25

Phloem Function

Answer 25

Transport tissue for dissolved sugars & amino acids

Question 26

Phloem Structure

Answer 26

Cells are alive, companion cells, cells contain holes in their end cell walls (sieve plates), very little organelles within the vessel

Question 27

Phloem Adaption

Answer 27

Cells are mostly living & are supported by companion cells (provide energy to the vessel)
Sieve plates act like a ‘sieve’, allowing sugars & amino acids to flow easily through
Little amount of organelles - aids flow of materials