Slides in this set
PLANT AND ANIMAL CELLS
Lots of CELLS make up a TISSUE
Animal and plant Just plant cells Lots of TISSUES make up an ORGAN
Lots of ORGANS make up an ORGAN SYSTEM
cells Lots of ORGAN SYSTEMS make up a full organism.
NUCLEUS RIGID CELL WALL
Controls activities of the cell and Made of CELLULOSE
contains genetic material. Supports cell and structures it. Specialised cells
Most are specialised for their specific
CYTOPLASM PERMANENT VACUOLE function.
Where chemical reactions happen; Contains cell sap. Used for storage
1) PALISADE CELLS are packed with
gel like substance contains
enzymes. chloroplasts for photosynthesis, they
have a thin shape so you can pack
CELL MEMBRANE CHLOROPLASTS loads in at the top of a leaf.
Holds the cell together and Where PHOTOSYNTHESIS occurs
controls what goes in and out. Contains CHLOROPHYLL which 2) SPERM CELLS have a streamlined
gives the plant it's green colour and head and long tail to help it swim to
the egg. They also have lots of
mitochondria to provide energy for
MITOCHONDRIA the journey!
Where reactions for
RESPIRATION takes place which
3)RED BLOOD CELLS have no nucleus
release ENERGY for the cell to and are packed with haemoglobin (which
work. absorbs oxygen)
Where PROTEINS are made in Stem cells are unspecialised and can be
the cell. (little dotty things) turned into any cell. They are taken from
embryos or bone marrow.…read more
DIFFUSION AND OSMOSIS
***** DIFFUSION OSMOSIS *******
The movement of particles from an area of THE MOVEMENT OF WATER
HIGH concentration to a LOW MOLECULES ACROSS A PARTIALLY
concentration. PERMEABLE MEMBRANE FROM A
*passive HIGH WATER CONCENTRATION TO
*happens in both liquids and gases
A LOW WATER CONCENTRATION.
*diffusion in air. e.g.. Perfume spreading across a room.
Partially permeable membrane has very small holes
The RATE of diffusion depends on;
in it that only tiny molecules (water) can pass through
1. distance, substances diffuse more quickly if they
and larger molecules (sucrose) can not. Water
haven't got as far to move..obviously.
molecules pass both ways through the membrane
2. Concentration difference (gradient) Substances
due to the random movement.
diffuse faster if there's a big difference in
-it's a type of diffusion.
concentration (more particles to move from one side
-passive movement of water particles
Water moves into and out of cells by OSMOSIS.
3. Surface area- the larger area the particles have to
Tissue fluid surrounds cells in the body. If a cell is
move across the faster they can get from one side to
short of water the solution inside will be
concentrated, and the solution outside more dilute.
So, water outside the cell will move into the cell by
osmosis to dilute it.…read more
WATER + CARBON DIOXIDE GLUCOSE + OXYGEN
Photosynthesis is the
-Takes place in the process which produces
CHLOROPLASTS which GLUCOSE (food) for plants
contain CHLOROPHYLL (the and gives off oxygen as a
substance that absorbs by product.
sunlight.) it uses this energy to
convert water and carbon It needs water from the soil
dioxide into glucose. Oxygen is and carbon dioxide from
also produced. *most the air. Chlorophyll absorbs
chloroplasts are found in leaf light energy from the sun to
cells. then produce glucose and
RATE OF PHOTOSYNTHESIS
The rate is affected by the amount of LIGHT, amount of CO2 & the TEMPERATURE.
The limiting factor means it is stopping photosynthesis from happening any faster.
It depends on the conditions.
Which factor is limiting at a particular time depends on the environmental conditions:
-At night, LIGHT is the limiting factor.
-In winter, it's often the TEMPERATURE.
-If it's warm enough, and bright enough the amount of CO2 is usually limiting.
Not enough light slows down the rate of photosynthesis. Too little carbon dioxide also slows it down. The
temperature has to be just right. (not too high or low for enzymes needed for photosynthesis to work)
You can artificially create the ideal conditions for farming.
If the conditions are just right for photosynthesis the plants will grow much faster and a decent crop can be
harvested more often, making more money for farmers.
-They do this in greenhouses which trap the sun's heat to make sure TEMPERATURE doesn't become a
-commercial farmers often supply artificial light, so even after the sun goes down plants can still
-farmers and gardeners can also increase the level of carbon dioxide in the greenhouse by using paraffin
heaters. Being closed in a greenhouse also keeps crops free from pests and diseases. Fertilisers may be
added to the soil as well.…read more