Information of cells and plants - b2 :)

HideShow resource information
Preview of AQA BIOLOGY B2

First 216 words of the document:

All animals and plants are made of cells. Animal cells and plant cells have features
in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and
ribosomes. Plant cells also have a cell wall, and often have chloroplasts and a
permanent vacuole. Note that cells may be specialised to carry out a particular
Dissolved substances pass into and out of cells by diffusion. Water passes into and
out of cells by osmosis.
Animal and plant cells
Function of cells which animal and plant cells have in common
part function
nucleus contains genetic material, which controls the activities of the cell
cytoplasm most chemical processes take place here, controlled by enzymes
cell membrane controls the movement of substances into and out of the cell
mitochondria most energy is released by respiration here
ribosomes protein synthesis happens here
Plant cells also have extra parts:
Extra parts of plant cells
part function
cell wall strengthens the cell
chloroplasts contain chlorophyll, which absorbs light energy for
permanent filled with cell sap to help keep the cell turgid
Make sure you can label diagrams of animal and plant cells, like these:

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Generalised animal and plant cell
Specialised cells
Cells may be specialised for a particular function. Their structure will allow them to carry
this function out. Here are some examples:
Examples of the functions of cells
Cell Function Adaption
Absorbs light Packed with chloroplasts. Regular shaped,
energy for closely packed cells form a continuous layer
photosynthesis for efficient absorption of sunlight.
Leaf cell
Absorbs water and Long 'fingerlike' process with very thin
mineral ions from wall, which gives a large surface area.…read more

Page 3

Preview of page 3

Page 4

Preview of page 4

Page 5

Preview of page 5

Here's a taster:

Dissolved substances have to pass through the cell membrane to get into or out of a cell.
Diffusion is one of the processes that allows this to happen.
Diffusion occurs when particles spread. They move from a region where they are in high
concentration to a region where they are in low concentration. Diffusion happens when
the particles are free to move. This is true in gases and for particles dissolved in
solutions.…read more

Page 6

Preview of page 6

Here's a taster:

Green plants absorb light energy using chlorophyll in their leaves. They use it to
react carbon dioxide with water to make a sugar called glucose. The glucose is
used in respiration, or converted into starch and stored. Oxygen is produced as a
This process is called photosynthesis. Temperature, carbon dioxide concentration
and light intensity are factors that can limit the rate of photosynthesis.
Plants also need mineral ions, including nitrate and magnesium, for healthy
growth.…read more

Page 7

Preview of page 7

Here's a taster:

Plants absorb water through their roots, and carbon dioxide through their leaves. Some
glucose is used for respiration, while some is converted into insolublestarch for storage.
The stored starch can later be turned back into glucose and used in respiration. Oxygen is
released as a by-product of photosynthesis.
Factors limiting photosynthesis
Three factors can limit the speed of photosynthesis - light intensity, carbon dioxide
concentration and temperature.…read more

Page 8

Preview of page 8

Here's a taster:

If it gets too cold, the rate of photosynthesis will decrease. Plants cannot
photosynthesise if it gets too hot.
If you plot the rate of photosynthesis against the levels of these three limiting factors,
you get graphs like the ones above.
In practice, any one of these factors could limit the rate of photosynthesis.
Maximising growth
Farmers can use their knowledge of these limiting factors to increase crop growth in
greenhouses.…read more

Page 9

Preview of page 9

Here's a taster:

The tomato plant on the left is healthy, the one on the right is growing in conditions where mineral ions
are deficient…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »