bio paper 1 Flashcards
nucleus
Contains genetic material that controls the activities of the cell
cytopasm
- gel like substance
- where most of the chemical reactions happen
- it contains enzymes that control these chemical reactions
cell membrane
- holds the cell together
- controls what goes in and out
mitrochondia
- these are where most of the reactions for aerobic respiration take place
- respiration trasfers energy that the cell needs to work
ribosomes
where proteins are made in the cell
cell wall
- made out of cellulous
- it supports and strengthens the cell
permanent vacuole
- contains cell sap (a weak solution of sugar and salts)
chloroplast
- where photosynthesis occurs (which makes food for the plants)
- they contain a green substance called chlorophyll (which absorbs light needed for photosynthesis)
plasmids
- small rings of DNA
- only in bacteria cells
define differentiation
the process by which a cell changes to become specialised for it’s job
- in most animal cells the ability to differentiate is lost at an early stage (after they become specialised)
- lots of plant cells don’t loose this ability
- differentiation is mature animals are mainly used for reparing and replacing cells (such as skin and blood)
cells differentiate to become specialised
name me 5 examples of a specialised cell
- SPERM CELLS - reproduction
- NERVE CELLS - rapid signaling
- MUSCLE CELLS - contraction
- ROOT HAIR CELLS - absorbing water and minerals
- PHLOEM AND XYLEM CELLS - transporting substances
function of xylem
Transports water and mineral ions from roots to leaves; provides structural support.
function of phloem
Transports sugars (glucose) and other nutrients from leaves to the rest of the plant (translocation)
how is a sperm cell specialised for reproduction
- Tail to swim to the egg
- Many mitochondria to release energy
- Streamlined head for faster movement
- Acrosome contains enzymes to digest egg membrane
how is a nerve cell specialised for rapid signalling
- Long axon to carry impulses over long distances
- Branched dendrites to connect to other nerve cells
- Myelin sheath to insulate and speed up impulses
- Lots of mitochondria to provide energy for transmitting signals
how is a muscle cells specialised for contraction
- Long so they can contract easily
- Lots of mitochondria to release energy
- Contain protein fibres that can contract
- Cells can work together in tissues for stronger contractions
how is a root hair cell specialised for absorbing water and minerals
- Long, thin extension: Increases surface area for more efficient absorption of water and minerals.
- Thin cell wall: Allows water to pass through easily by osmosis.
- Large vacuole: Helps maintain osmotic gradient for water uptake
- Many mitochondria: Provide energy for active transport of mineral ions.
- No chloroplasts: As they are underground and do not perform photosynthesis.
how is phloem different from xylem
list chromosomes, gene, DNA in order to smallest to biggest
