specialised cells/tissues

Question 1

erythrocytes specialisation

Answer 1

• flattened biconcave disc shape (higher SA:V)
• (Mammals) no nucleus or many other organelles (e.g. mito) to increase space for Hb
• Flexible; can squeeze through narrow capillaries

Question 2

Neutrophils specialisation

Answer 2

• multi-lobed nucleus; easier for them to squeeze through small gaps to reach sites of infection.
• Granular cytoplasm; many lysosomes

Question 3

sperm cells specialisation

Answer 3

• helical mitochondria for ATP production for mvmt
• tail/flagellum for mvmt
• acrosome to digest outer protective layers of egg

Question 4

palisade specialisation

Answer 4

• (present in mesophyll)
• chloroplasts for P/s
• rectangular shape allows for close packing
• thin cell walls for a higher rate of diffusion of CO2
• large vacuole to maintain turgor pressure
• chloroplasts can move within the cytoplasm to absorb more light.

Question 5

Root hair cells specialisation

Answer 5

• long extensions (root hairs) which increase SA.

Question 6

guard cells specialisation

Answer 6

cell wall of a guard cell is thicker on one side so the cell does not change shape symmetrically when the turgor pressure changes.

Question 7

squamous epithelium specialisation

Answer 7

• very thin; short diffusion distance of only 1 cell
• present when rapid diffusion is essential e.g. lining of lungs

Question 8

ciliated epithelium specialisation

Answer 8

• cilia move in a rhythmic manner; mucus swept away
• goblet cells are also present, releasing to trap unwanted particles e.g. bacteria from reaching the alveoli once inside the lungs.

Question 9

cartilage specialisation

Answer 9

• fibres of proteins: elastin and collagen.
• Firm, flexible
• Composed of chondrocyte cells embedded in an extracellular matrix
• Prevents the end of bones from rubbing together and causing damage
• many fish skeletons are cartilage, not bone