biology 2a - Cells, Organs and Populations 0.0 / 5 ? BiologyCells, tissues and organsGCSEAQA Created by: wseneCreated on: 21-02-14 15:16 What are specialised cells? They carry out particular functions. 1 of 14 What is a guard cell? A special kidney shape which opens and closes the stomata in a leaf. (adapted to open and close pores). 2 of 14 Why does the stomata close? When a plant is short of water the stomata closes to prevent the loss of water vapour. 3 of 14 Why do the stomata open? When a plant has a lot of water the guard cells swell up. They open to allow the exchange of gas for photosynthesis. 4 of 14 What is the function of the red blood cell? It absorbs and carries oxygen. 5 of 14 What is haemoglobin? It is the pigment that absorbs the oxygen. 6 of 14 What are sperm and egg cells specialised for? Reproduction 7 of 14 What helps guard cells function? They have thin outter walls and thick inner walls to help open and close. 8 of 14 What is the purpose of the blood cells shape? Its concave shape gives a big surface area for absorbing oxygen. 9 of 14 Why does a blood cells not have a nucleus? So it can allow more room for haemoglobin. 10 of 14 What is the job of an egg? Carries the females DNA to and nourishes the embryo in its early stages. 11 of 14 What is the job of the sperm? To fertilise the egg and carry male DNA to the female DNA. It also has a long tail and a streamlined head to swim to the egg. 12 of 14 What extra information does the sperm contain? Enzymes in their heads to digest through the egg cell membrane. It also contains mitochondria to provide energy to swim to the egg. 13 of 14 What happens when the sperm and egg fuse together? The fusion stops any other sperm cells getting into the egg by the eggs membrane instantly changing. this allows the right amount of DNA. 14 of 14
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