4.1.3 - Cells in Animals and Plants Flashcards
(44 cards)
Describe what a eukaryotic cell is
A cell which has a nucleus. It also has other structures in the cytoplasm with a membrane around it.
What is the function of the cell membrane?
Controls the movement of substances in and out of the cell.
Examples include glucose, water, energy, and CO2.
Describe what a prokaryotic cell is
A cell which does not have a nucleus. The DNA is free in the cytoplasm.
Give two examples of a eukaryotic cell
Plant and animal cells.
Give one example of a prokaryotic cell
Bacterial cells.
What is the function of the cell wall?
Made of cellulose in plants, supports and strengthens the cell.
What is the function of the nucleus?
Contains genetic material which controls the cell’s activities and division.
What is the function of mitochondria?
Where aerobic respiration takes place, releasing energy.
What is the function of chloroplasts?
Contains chlorophyll, which absorbs light for photosynthesis.
What is the function of ribosomes?
Where protein synthesis occurs
Define diffusion.
The movement of fluid molecules from and area of higher concentration to an area of lower concentration.
Give an example of diffusion in animals/plants.
Minerals and water diffuse into the plant through the roots
State three factors which affect diffusion.
- Difference in concentration
- Temperature
- Surface area
Define osmosis.
Diffusion of water across a partially permeable membrane from a region of higher water concentration to lower water concentration.
Give an example of osmosis in animals/plants.
In an animal cell, osmosis helps in absorbing water from the intestines to the blood
What is a partially permeable membrane?
A membrane that allows water and small molecules to pass through but not large molecules like starch.
Define active transport.
A process that is required to move molecules against a concentration gradient. Requires energy from respiration.
Give an example of active transport in animals/plants.
absorption of glucose in the small intestine
How is active transport different from diffusion and osmosis?
It goes against the concentration gradient.
What are the two types of microscopes?
Electron and light microscopes.
Which microscope has a higher magnification and resolution?
Electron microscope.
What is the magnification if a magnified image is 2mm wide and the specimen is 0.02mm wide?
x100
Magnification is calculated as 2mm ÷ 0.02mm.
Define magnification.
How many times bigger the image of a specimen observed is compared to the actual size.
Define resolution.
The ability to distinguish two separate objects. The higher the resolution of an image, the more detailed it is.
