2.6.7 Specialised Cells

Question 1

What is specialisation

Answer 1

• Where cells develop structural adaptations to carry out different functions in tissues
• Eg. Organelles within cells, shape of cell

Question 2

How are RBCs specialised

Answer 2

Biconcave - Increased SA across which oxygen can be absorbed

Contains lots of haemoglobin - Can readily bind to oxygen

No nucleus present - More space for haemoglobin

Elastic membrane - cell can be flexible as it squeezes through narrow capillaries

Question 3

How are Neutrophils specialised

Answer 3

Flexible - Can squeeze through cell junctions in capillary walls

Flexible - Cytoplasm can extend in phagocytosis

Lots of lysosomes - Can digest invading cells

Question 4

How are sperm cells specialised

Answer 4

Function - Fuse with an egg, initiating development of an embryo while passing on paternal genes

Head - contains nucleus with half number of normal chromosomes

Acrosome in head - Digestive enzymes break down outer layer of egg so haploid can fuse with egg’s nucleus

Mitochondria - Releases energy via aerobic respiration for tail movement

Tail - Can move towards egg

Question 5

How are Root hair cells specialised

Answer 5

Root hair - Increases SA so rate of water uptake by osmosis is greater

Thin walls - Short diffusion distance

Permanent Vacuole - Contains cell sap, more concentrated than soil water, so creates water potential gradient

Mitochondria - To release energy for active transport of mineral ions

Question 6

How are ciliated epithelium specialised

Answer 6

Cilia - waft material towards mouth to be swallowed

Goblet cells - secrete mucus trapping dust and microbes

Question 7

How are Squamous Epithelium specialised

Answer 7

Flattened cells - short diffusion distance

Permeable - For diffusion of gases

Question 8

How are palisade cells adapted

Answer 8

Lots of chloroplasts - For maximum absorption of light for photosynthesis

Tall and thin - cells can densely pack together

Question 9

How are guard cells specialised

Answer 9

Function : Controlling opening and closing of stomata to regulate water loss and gas exchange

Inner walls are thicker, outer walls thinner - Difference in thickness of cell walls allows cell to bend when turgid

Lots of chloroplasts and mitochondria - Energy for opening and closing of stomata