Tech Applied Science Unit 1 Biology. Specialised cells. There are some cells that do particular jobs. They are specialised. Understand cell specialisation in terms of structure and function.
So basically for these cells, be able to do a label diagram, certainly be able to recognise one. Say what job does this cell do? And how is it adapted to do its job? How is it designed to do its job in terms of its structure?
First one, palisade mesophyll cells in a leaf, basically leaf cells. And their main function is photosynthesis. And to enable them to do this, they contain a lot of chloroplasts because that's where photosynthesis happens in the chloroplasts. they have a large vacuole and because of that the chloroplasts are in the outer regions of the cell which is where they're going to get exposed to sunlight and they have thin cell walls to enable diffusion of substances so these are leaf cells or palisade mesophyll cells also in a plant there are root hair cells and their job is to collect water and mineral nutrients from the soil.
They are in the soil underground. To enable them to do this they have lots of little hairs sticking out, long projections which reach out into the soil and that means they have a large total surface area. They don't contain chloroplasts because photosynthesis doesn't take place in them.
If you look at them they are white. and not green because they don't contain chloroplasts. Some animal cells now. Now egg cells and sperm cells. The egg cells, they carry the genetic information from the female in the haploid nucleus.
Okay, if we're talking humans then you're talking 13 chromosomes from your mum. There are different bits of it if you look at the diagram. The zona pellucida is a jelly layer that stops more than one sperm getting in.
The sperm cell carries the genetic information from the male in the haploid nucleus. In the case of humans it's 13 chromosomes from daddy. They have a tail for swimming which is called an undulipodium.
That's the tail for swimming to the egg, for the journey to the egg. The middle bit before the tail contains lots of mitochondria to provide energy, the energy needed to swim to the egg. White blood cells, now their job is to protect the body against infectious diseases and foreign invaders.
They fight against pathogens. They can change shape so that they can squeeze through gaps. They can get to the sites of infection and they engulf the invaders. They swallow them up like the blob. They produce a range of chemicals, that should say, not rage.
A range of chemicals. They produce antitoxins. because some of these pathogens produce poisons, toxins, then this is the antidote, the antitoxins, and they produce antibodies and particular antibodies will attack particular pathogens.
Red blood cells and their function is to carry oxygen in the bloodstream. The oxygen binds with a chemical called haemoglobin which is the red stuff and when the oxygen binds to it it becomes oxyhemoglobin it becomes bright red so on the surface of the cell the hemoglobin carries the oxygen how are they designed to do their job their shape which is a biconcave disc and that gives them a very large surface area they are small and flexible so they can squeeze through tiny blood vessels they can squeeze through Capillaries. These are red blood cells.