This is where photosynthesis occurs, which makes food for the plant. They contain chlorophyll - a green pigment - which absorbs light needed for photosynthesis
Cytoplasm, cell membrane, cell wall, flagella, ribosomes, mitochondria, slime capsule, plasmids (small rings of DNA) and a single circular strand of DNA that floats freely in the cytoplasm
Osmosis is the passive movement of water molecules through a partially permeable cell membrane from an area of high water concentration to an area of low water concentration
Explain how the leaves are adapted to maximise the amount of carbon dioxide that gets into their cells
1) The exchange surface in a leaf is covered in stomata which the carbon dioxide diffuses through
2) The leaf has a flattened shape which increases the area of its exchange surface, therefore it's more effective
3) The walls of the cells inside the leaf act as another exchange surface
4) The air spaces inside the leaf increase the area of the exchange surface which increases the chance for carbon dioxide to enter the cellsSee an expert-written answer!We have an expert-written solution to this problem!
Plants = Root hairs absorb minerals and water. Each branch of a root will be covered in tiny hairs, therefore increasing the surface area for the absorption of minerals and water. The concentration of minerals is usually higher in the root hair cells than in the soil around them, therefore they can't use diffusion for this process.
Animals = Glucose is taken in from the gut and from kidney tubules.
-Each gill is made up of lots of gill filaments which create a large surface area for the exchange of gases
-Gill filaments are covered in lamellae which increase the surface even more
-The lamellae have lots of blood capillaries to speed up diffusion
-The lamellae have a thin surface layer of cells to minimise the diffusion distance
-Blood flows through the lamellae one way and water flows over in the opposite direction which maintains a higher concentration gradient between the blood and the water
-The concentration of oxygen in the water is always higher than that in the blood to maximise the amount of oxygen diffusion from the water into the blood
1) Add a drop of water to the middle of a clean slide
2) Cut up an onion & separate it out into layers. Use tweezers to peel off some epidermal tissue from the bottom of one of the layers
3) Using the tweezers, place the epidermal tissue into the water on the slide
4) Add a drop of iodine solution - a stain used to highlight objects in a cell by adding colour to them
5) Place a cover slip on top - stand the cover slip upright on the slide, next to the water droplet. Then, carefully tilt & lower it so it covers the specimen. Try not to get any air bubbles under there - there'll obstruct your view
2) The cell gets bigger & the circular DNA strands move to opposite poles of the cell
3) The cytoplasm begins to divide & new cell walls begin to form
4) The cytoplasm divides & two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but can have a variable number of copies of the plasmid(s)