SPECIALISATION AND ORGANISATION.

Question 1

Formation of xylem and phloem from meristems.

Answer 1

• Meristem elongates, they waterproof walls with lignin and end cell walls break down, this forms long tubes which makes xylem tissues.
• Meristem elongates and end cell walls don’t break down fully, sieve plates form between cells.

Question 2

Medical uses for stem cells.

Answer 2

• Alzheimer’s.
• Parkinson’s.
• Repairing damaged tissues.

Question 3

Alzheimer’s.

Answer 3

• Nerve cells in the brain die in increasing numbers.
• Severe memory loss.
• Use stem cells to grow healthy nerve cells.

Question 4

Parkinson’s.

Answer 4

• Loss of dopamine producing nerve cells in the brain.
• Uncontrollable tremors.
• Use stem cells to regenerate cells.

Question 5

Heart disease.

Answer 5

• Damaged heart tissue.
• Unable to sufficiently replace cells.
• Use stem cells to make replacement heart cells.

Question 6

SPECIALISED CELLS - Erythrocytes (Function, adaptation+ how it aids function).

Answer 6

• Transport oxygen from alveoli to tissues.
• No nucleus, Bi-concave disk.
• More space for haemoglobin + increases surface area.

Question 7

Neutrophil.

Answer 7

• Phagocytosis.
• Contains many lysosomes, packed with enzymes.
• Allows pathogens to be digested.

Question 8

Squamous epithelial cells.

Answer 8

• To line organs.
• Very thin cell.
• Creates a short diffusion distance.

Question 9

Ciliated epithelial cellls.

Answer 9

• To move substances.
• Cilia can waft.
• Cilia moves substances along.

Question 10

Sperm cell.

Answer 10

• Fertilises egg.
• Tail, Lots of mitochondria, Enzymes in acrosome head.
• Mitochondria provide ATP for movement. Enzymes allow the head to penetrate egg cell membrane.

Question 11

Palisade cell.

Answer 11

• Photosynthesis.
• Lots of chloroplasts.
• More light can be absorbed.

Question 12

Root hair cell.

Answer 12

• Absorbs water and mineral ions by active transport.
• Many mitochondria, thin permeable cell wall, larger surface area.
• Create ATP for active transport.

Question 13

Guard cells.

Answer 13

• Allow gas exchange in the leaf.
• Thin outer walls and thick inner walls.
• Allows cells to bend and open the stomata.

Question 14

Pluripotent stem cells.

Answer 14

• Can differentiate into any body cells.

Question 15

Totipotent stem cells.

Answer 15

• Can differentiate into any body cell + embryonic / placental cells.

Question 16

Multipotent stem cells.

Answer 16

• Can differentiate into particular cells e.g bone marrow- red and white blood cells.

Question 17

Tissues.

Answer 17

• Group of cells working together to perform the same function.

Question 18

Organs.

Answer 18

• Group of tissues working together to perform the same function.

Question 19

Organ system.

Answer 19

• Group of organs working together to perform the same function.

Question 20

Names of tissues.

Answer 20

• Muscles, Cartledge, Ciliated + Squamous epithelial tissue.

Question 21

cell-system (muscle, ciliated e, squamous e, cartiledge)

Answer 21

(fibres, muscle, heart, circulatory)
(c.e cell, c.e, lungs, respiratory)
(s.e cell, s.e, alveoli, respiratory)
(chondrocyte, cartilage, trachea, respiratory)