biology y9 Flashcards
What is magnification?
Imagine divided by Actual size
What do ribosomes?
Protein-syenthesis
What does the cell membrane do?
Control movement of liquid in and out of the cell
What does the cell wall do?
Provides support and strength for the cell.
What does the nucleas do?
It stores genetic material (DNA) and control cell activity
What does the mitrochondria do?
It provides energy for the cell through respiration
What does the cytoplasm do?
Where most chemical reactions take place.
What is a partialy perm-able membrane?
Something that only allows certain substances through.
What is osmois?
The movement of water molecules across a partially perm-able membrane. From a concertrated solution to a dialute solution.
What is diffusion?
The movement of particles from a high concertration to a low concertration
What do both plant cells and animal cells have?
cell membrane , mitchrondria , ribosomes , nucleas and cytoplasm.
What features does a plant cell have that a animal cells does not?
Chloropast , Cell Wall and Vacuole.
What is active transport?
The movement of substances between their against their concertration gradient using energy from respiration.
When is active transport useful in plant cells/animal cells?
In animal cells, it is used in the gut to absorb nutrients from our food.
In plant cells, Root hair cells absorb minerals from the soil.
How are sperm cells specialised?
They have a long tail, stream lined head, lots of mitrochondria and enzymes to help digest the cell membrane of a egg cell. (All for reporduction)
How are nerve cells specialised?
They are in loops and have send electrical impulses to make connections. (For rapid signalling.)
How is a muscle cell specialised?
They contain lots of mitrochondria so they can release energy for respiration. (For contracting)
How is a root hair cell specialised?
They have hairs that increase their surface area. (For absorbing water and minerals)
How is a phyloem and Zylumn cell specialised?
Zylumn cells are hollow in the centre and Phyloem cells have very conjointed stems so that subtances can feed through them.
Give a example of a eukoryotic cell and a prokrayotic cell
For Euckoryotic, The Phyloem cell.
For Prokayrotic, The bacteria cell.
What is a stem cell?
A cell that has not been specialised. It can be found in the early human embyro.
Why are people against stem cell research?
People think its unethical to kill human embroys and they believe that they are playing “god”.
What are the benifits of stem cell research?
Helps us develop medicine and can produce identitcal plants.
How are alveoli adapted to maximise defusion?
They have a large surface area , Tight walls and lots of capilaries.
