B1 Flashcards
Livings thing are made of ….
Cells
Cells can be
Prokaryotic or eukaryotic cells
Eukaryotic cells
Are complex and include all animals and plant cell
Prokaryotic cells
Are smaller and simpler
Plant cells contain
Rigid cell walls made of cellulose
Permanent vacuole contains cell sap
Chloroplasts-these are where photosynthesis occurs and chlorophyll to absorb light
Nucleus controls the activities of cells
Cytoplasm - gel like substance that contains all chemical reactions
Cell membrane holds the cells together and controls what goes in and our
Ribosomes- where proteins are made
Mitochondria-there are where most of the reactions for aerobic respiration happens.
Animal cells cointain
Nucleus controls the activities of cells
Cytoplasm - gel like substance that contains all chemical reactions
Cell membrane holds the cells together and controls what goes in and our
Ribosomes- where proteins are made
Mitochondria-there are where most of the reactions for aerobic respiration happens
Bacterial cells
Prokaryotes
Cell well to keep it sturdy
Cytoplasm - gel like substance that contains all chemical reactions
Cell membrane holds the cells together and controls what goes in and our
Bacteria doesnt have a nucleus but single strands of DNA
Magnification =
Real size
How do you prepare a slide
1) add a drop off water to a clean slide
2) cut up an onion and separate out its layers
3) using tweezers place the epidermal tissue into the water on the slides
4) add a drop iodine solution to stain it
5) finally place a cover tip on top
Cell differentiation is
The process of the cells changing into specialised cells
Nerve cells are
Cells specialised ro carry electrical impulses around the body of an animal.
Muscles cells can
Contract or relax to move the bones of the skeleton
Sperm cells have
- A long tail to help the sperm move
- The middle section is full of mitochondria which gives energy for the tail
- the tip called the acrosome is contains enzymes that breaks down the outer layer of the egg
- a large nucleus contains the genetic information
Root hair cell
- They have a large surface area
- they have large permanent vacuole that speeds up the movement of water
- have the mitochondria that transfer the energy needed for active transport.
Photosynthetic cells
-they contains chloroplasts containing chlorphyll which traps light to get its energy
Where are xylem cell found
In plants
Xylem cells
-transport tissue which carries water and mineral
Diffusion
-diffusion is the spreading of particle or any substance in a solution. This happens when it goes from a high concentration to a low concentration
What is an adaption of cells to increase diffusion
Increased surface area
Rates of diffusion
If there is a a big difference in concentration between two areas it will happen quickly
Diffusion in Humans examples
Kidney and gas exhange
What is Osmosis
A process in which molecules pass through a partially permeable membrane to go from high to low concentration.
How osmosis differs from diffusion
- a dilute solution of sugar contains high concentration of water but low concentration of sugar
- a concentration sugar solution contains relatively low concentration of water by high concentration of sugar
What is the cytoplasm made of
The cytoplasm is made up of chemical dissolved in water inside a partially permeable membrane
What does the cytoplasm contain
The cytoplasm contains fairly concentrated solution of salt and sugars.
How does water move in osmosis
Water moves from a dilute solution (with high con of water low con of sugar) to a concentered solutions (with fewer water molecules and more sugar molecules)
Isotonic means
The concentration outside the same is the concentration inside the cell
Hypertonic means
This is when concentration outside is higher than the concentration inside the cell. This cause it to shrivel
Hypotonic means
This when concentration outside the cell is lower than the concentration inside the cell. This causes the cell to burst
How is osmosis used in cells
If a cell uses up water the cytoplasm will become more concentrated. The surrounding fluid becomes hypotonic to the cell and more water moves in.
Why do plants rely on osmosis
To support their stems and leaves.
How does osmosis support stems and leaves
The stem and leaves become hard and rigid when the cell become hard and rigid due to turgor pressure,where no more water can enter the cell.
