biology - cells

• plant and animal cells are example of eukaryotic cells
• the cytoplasm is controlled by enzymes. most chemical processes occur here
• the nucleus contains genetic material which controls the activities of the cell
• the cell membrane controls the movement of things in and out of the cell
• ribosomes are the site of protein synthesis
• mitochondria releases energy by respiration
• the cell wall strengthens the cell and keeps it turgid
• chloroplast contains chlorophyll and carries out photosynthesis
• the vacuole is filled with cell sap to help keep the cells turgid
• the structure of a eukaryotic cell is genetic material inside a nucleus
• a stain is used to highlight key features you are trying to observe
• total magnification is calculated by doing eye piece magnification x objective lens magnification
• magnification is how many times bigger an object actually is
• a specialised cell is a cell designed or adapted to carry out a particular function
• sperm cell, nerve cell, fat cell and muscle cell are all examples of specialised cells in animals
• xylem cells, phloem cells, root hair cells and palisade cells are all example of specialised cells in plants
• unspecialised cells are called stem cells
• differentiation is the process where stem cells differentiate to become any type of specialised cell needed by the body
• a red blood cell is a biconcave disc with a thin membrane and no nucleus.
• the function of a red blood cell is to transport oxygen around the body
• the haemoglobin picks up the oxygen from the lungs and transports it around the body
• the function of a fat cell is to fill up with fat to enable animals to survive when there is a food shortage
• fat cells only have small amounts of cytoplasm and mitochondria because they need to store large amount of fat
• the function of muscle cells are to contract so that we can move our bodies
• the function of a palisade cell is to make food (sugar) using sunlight in photosynthesis
• a palisade cell is adapted for photosynthesis because it contains lots of chloroplasts
• the tail on a sperm cell helps it to swim quicker towards the egg
• a sperm cell fertilises the female egg and contains DNA in its head.
• the 7 parts of a microscope are the stage, objective lens, light, eyepiece lens, coarse focus, clips and fine focus
• the function of a root hair cell is to enable plants to absorb water and minerals
• root hair cells have a large surface area so they are able to carry more minerals
• the function of the xylem is to carry water and mineral ions into the rest of the plant
• it is good for the cell to be close to the xylem because plants need water and dissolved mineral ions
• the function of the myelin sheath is to insulate the axon to prevent loss of the impulse and makes it travel quickly
• the function of phloem is to transport sugars from leaves to other parts of the plant
• the function of a nerve cell is to carry impulses around the body to enable us to respond to our environment
• the dendrites provide the nerve cell with a large surface area
• a large surface area enables the nerve cell to receive information which they pass on
• stem cells have specific functions in embryos, adult animals and in the meristem of plants
• stem cells from human embryos can be cloned and made to differentiate into most different types of human cells