B2- Cells, Tissues and Organs Flashcards
Define diffusion.
The movement of gas or liquid molecules from a region of high concentration ➡️low concentration.
Give three examples of diffusion.
- Diffusion of oxygen into cells from bloodstream/ Diffusion of CO2 out of cells as a product of respiration.
- Neurotransmitters diffuse across a synapse.
- Products of digestion diffuse from small intestine into blood.
Describe where DNA is found in a human cell (2 marks).
The DNA is in the chromosomes, in the nucleus of a human cell.
How does the structure of ciliates epithelial cells link to their function?
Tiny little hairs protruding from the surface pushes the mucus into the throat so it can be coughed up.
Bacteria contain…
- A cell membrane and cell wall.
- Cytoplasm and ribosomes.
- NO NUCLEUS so genetic material is in the cytoplasm.
Animals tissues include…
Muscle tissue- can contract to bring about movement.
Glandular tissue- produce substances such as enzymes and hormones.
Epithelial tissue- covers some parts of the body.
Most animal cells contain…
- A nucleus.
- A cell membrane.
- Cytoplasm.
- Mitochondria.
- Ribosomes.
Define xylem tissue in plants.
Transports water and salutes from roots to leaves.
How does the structure of sperm cells link to its function?
Streamlined- reduces resistance.
Tail- tails propels them forward.
Mitochondria- more respiration = more energy.
What is the function of chloroplasts?
Chloroplasts contains chlorophyll which absorbs light for photosynthesis.
Define a tissue.
A tissue is a group of specialised cells that have a similar structure and function.
What is the function of a vacuole?
The vacuole contains cell sap to keep the cell enlarged and turgid with water.
What is the function of a cell wall?
The cell wall supports/strengthens the cell and stops it bursting.
The stomach is an organ made out of:
- Muscular tissue to churn food and other contents.
- Glandular tissue to produce digestive juices like acids and enzymes.
- Epithelial tissue to cover the inner and outer surfaces of the stomach.
The digestive system is a muscular tube which includes:
Pancreas and salivary glands- to produce digestive juices.
Liver- to produce bile which emulsified fats and neutralises stomach acid.
Small intestine- to digest and absorb soluble food.
Large intestine- to absorb water from undisgested food, producing faeces.