specialised cells and differentiation

• a specialised cell has adapted special features to be able to carry out a specific function within an organism
• specialisation may come in the form of different organelles, a larger or smaller sized cell, more organelles than usual or a complete lack of cells
• the red blood cell transports oxygen all around the body for respiration and has a large surface area so more oxygen can be transported. it also has no nucleus so more space for the oxygen. contains a protein called Hemoglobin. red blood cells are small and flexible so they can fit through small spaces as they are all around the body in the blood circulatory system.
• the nerve also known as the neuron carries nerve impulses to different parts of the body. they are long, they have a long way to travel and have a both end connection so messages can be received and passed on carry electric signals .nerves are located in the nervous system. dendrites provide a large surface area for connections to synapses on other nerves. the synapses allow messages to pass from one neuron to another. myelin sheath insulates the axon and speeds up the impulse transmission
• the palisade cell absorbs sunlight water and nutrients for photosynthesis. filled with chloroplasts to maximise sunlight absorbed. a large surface area to absorb lots of water and nutrients.
• the root hair cell absorbs water and minerals and has a large surface area which maximises the amount of water and nutrients . has a thin membrane making it easier for substances to be absorbed from the soil.no chloroplasts as root hair cells are only found underground in the soil where there is no sunlight
• differentiation is the process of a cell becoming specialised.
• differentiation happens in a plant cell throughout the entire life of the plant which is why you can grow a new plant just by a cutting but you cant grow a new human from an amputated leg
• differentiation happens in animals when it is an embryo when the egg has been fertilised by sperm and development of an embryo .bone marrow produces undifferentiated cells but these can only become red blood cells, white blood cells or platelets
• the sperm cell swims to the ovum and fertilises it. it has a long tail called the flagellum to help it swim to the egg and enzymes at the head of the sperm to penetrate and fertilise the egg and is located in the testicles of the male reproductive system. it also has lots of mitochondria as it needs lots of energy to get to the ovum, the nucleus contains half the usual amount of genetic information.
• the muscle cell contains protein fibres that contract so that we can move. they also have lots of mitochondria as lots of energy is needed during the movement of the muscles
• the ovum also said as the egg is fertilised and then provides food to the developing embryo.large surface area increasing the chance of fertilisation and has cytoplasm which has yolk which is food that helps the embryo grow and is located in the ovaries of the female reproductive system