Neutrophils:
- Phagocytic leukocytes which are involved in one of the early lines of defence against pathogens by removing bacteria that have entered the body
- They have a nucleus with 2-5 lobes and contain organelles called lysosomes (contain digestive enzymes)
Squamous epithelial cells:
- are round and flat with a small, centrally located nucleus
- the cells fit together to form a covering/lining
- When arranged together in a single layer, they facilitate diffusion in tissues such as- gas exchange in lungs, nutrient and waste exchange in blood capillaries.
Ciliated epithelial cells:
- Have cilia on the apical surface of each cell
E.g. the pseudo stratified column or epithelia in the respiratory tract
-the cilia enhance the movement of mucus and trapped particles out of the respiratory tract through a wafting motion
- This helps protect the body from pathogens and harmful material that has been inhaled.
- This helps protect the body from pathogens and harmful material that has been inhaled.
Guard cells:
- surround the stomatal pore and control the opening and closing of the stomata
- the osmotic state within the guard cells determines their turgor; When the guard cells are flaccid, the stomata close/ when the guard cells are turgid, the stomata open.
- Turgor is regulated by the active transport of ions, such as K+ and H+ across the plasma membrane
Sperm cells:
- Male reproductive cells (gametes) which fuse with an egg cell during fertilisation to form a zygote
- To ensure the zygote has one complete diploid set of chromosomes both egg and sperm cells are haploid and only one sperm fuses with one egg.
- the acrosome in the head of the sperm contains digestive enzymes which degrade the zona pellucida surrounding the egg cell, allowing the plasma membrane to fuse with the egg plasma membrane.
- To ensure the zygote has one complete diploid set of chromosomes both egg and sperm cells are haploid and only one sperm fuses with one egg.
- the acrosome in the head of the sperm contains digestive enzymes which degrade the zona pellucida surrounding the egg cell, allowing the plasma membrane to fuse with the egg plasma membrane.
Root hair cells:
- specialised to increase the efficiency of water absorption and the uptake of minerals required for the plants survival.
- the root hairs are long projections that increase the surface area that plants can use to absorb water and minerals
- Are underground so do not contain chloroplasts.
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