2.1.6 Cell cycle - specialised cells Flashcards
What is the organisation of a multicellular organism?
Specialised cells –> tissues –> organs –> organ systems –> whole organism
Define differentiated
Specialised to carry out very specific functions.
How are Erythrocytes (red blood cells) specialised?
Flattened and biconcave shape - Increases their surface area to volume ratio (which is essential for their role of transporting oxygen around the body).
Doesn’t have nuclei or any other organelles - Increases the space available for haemoglobin.
Flexible / malleable - Allows them to squeeze through narrow capillaries.
How are Neutrophils (type of white blood cell) specialised?
Multi-lobed nucleus - Makes it easier for them to squeeze through small gaps to get to the site of infections.
Granular cytoplasm contains many lysosomes that contain enzymes - Used to attack pathogens
How are sperm cells specialised?
They have a flagellum - So they are capable of movement
Contain many mitochondria near the flagella - To supply energy needed to swim
Acrosome contains digestive enzymes - Which are released to digest the protective layers around the ovum and allow the sperm to penetrate, leading to fertilisation.
How are palisade cells specialised?
Rectangular box shapes - Can be closely packed to form a continuous layer.
Thin cell walls - Increases the rate of diffusion of carbon dioxide.
Contains a large vacuole - To maintain turgor pressure
Chloroplasts can move within the cytoplasm - To absorb more light
How are root hair cells specialised?
Surface of roots have long extensions called root hairs Increases the surface area. This maximises the uptake of water and minerals from the soil.
How are Guard cells specialised?
Cell wall is thicker on the inside So the cell does not change shape symmetrically as its volume changes.
How do guard cells work?
Guard cells are necessary for carbon dioxide to enter plants for photosynthesis. When guard cells lose water and become less swollen as a result of osmotic forces, they change shape and the stomata closes to prevent further water loss from the plant.
