Cell Biology Flashcards
(24 cards)
What factors affect the rate of diffusion?
- Temperature
- Diffusion distance
- Liquid or gas
- Particle size
- Concentration
- Gradient
What is the function of the cell wall?
It supports the cells and maintains the shape of the cell
What is a chromosome?
A long molecule of DNA containing a large number of genes
How is a palisade cell specialised?
- Packed with chloroplasts for photosynthesis
- Tall shape gives it a large surface area for absorbing Carbon Dioxide
- Thin shape means you can pack a lot of them at the top of the leaf
What is active transport?
It absorbs molecules against a concentration gradient using energy released by mitochondria
What is diffusion?
Random movement of particles from an area of high concentration to an area of low concentration
What is a stem cell?
A cell that can differentiate into any other kind of cell
How is a red blood cell specialised?
- Doesn’t contain a nucleus
- Packed with haemoglobin to allow it to carry oxygen
- Has a biconcave shape to give it a big surface area
What is an organ?
A group of different tissues working together to do a particular job
How is a bacterial cell different?
- They don’t have a nucleus
- They have a cell wall that’s not made of cellulose
- Their DNA is a circular molecule called “Plasmid”
What is the function of the ribosome?
Makes proteins like enzymes and hormones
What is the function of the nucleus?
It controls the activities of the cell
How do you calculate magnification?
Magnification = Image size / Real size
Why are chromosomes in pairs?
One member of each pair comes from the male parent and one from the female parent
What is the function of the mitochondrion?
Carries out Aerobic respiration to release energy from glucose
Name three animal tissues.
- Muscular tissue, which contracts
- Glandular tissue, which makes enzymes
- Epithelial tissue, which acts as a protective layer
What is Osmosis?
The diffusion of water from a high water concentration to a low water concentration through a selectively permeable membrane
What is a tissue?
A group of similar cells that do the same job
What is the function of the chloroplast?
Carries out photosynthesis
What is the function of the cell membrane?
Controls the movement of materials into and out of the cell
What is a gene?
A section of DNA that codes for the production of one protein
What is mitosis?
When a cell divides to produce new cells with identical nuclei
How is a sperm cell specialised?
- It’s streamlined to help it swim to the egg
- It’s nucleus contains half the normal number of chromosomes
- It has lots of mitochondria to provide the energy for movement
- Has enzymes in the head to help it pass through the egg cell membrane
How is a cell from a villus (small intestine) specialised?
- Lots of ribosomes to make enzymes
- Lots of mitochondria to release energy for active transport
- Lots of extensions to increase surface area
