Palisade leaf cells are adapted for photosynthesis.
1. They are packed with .... for photosynthesis, more crammed at the top so they're nearer the light.
2. They are .... which means they have a large surface area exposed down the side for absorbing CO2 from the air in the leaf.
3. A ... shape means that you can pack loads of them at the top of a leaf.
1. They are packed with chloroplasts for photo photosynthesis.
2. They are tall which means they have a large surface area exposed down the side for absorbing CO2 from the air in the leaf.
3. A thin shape means that you can pack loads of them at the top of a leaf.
Where are palisade leaf cells found?
Grouped together at the top of the leaf where the most photosynthesis happens.
What are the 3 main functions of the egg cell?
To carry the female DNA.
To nourish the developing embryo in the early stages.
It also contains huge food reserves to feed the embryo.
Palisade leaf cells are adapted for.... .
Palisade leaf cells are adapted for photosynthesis.
Give an example of an organ system and describe it...
1. The system and overall function
2. Organs it's made up of and functions (5)
How does this system interact with the envrinoment?
The digestive system for breaking down food to extract nutrients
1. Glands (slaivary and the pancreas) produce digestive juices
2. The stomach and small intestine digest food
3. The liver which produces bile
4. The small intestine absorbs soluble food molecules.
5. The large intestine absorbs water from undigested food leaving faeces.
It exchanges materials by taking in nutrients and releasing substances such as bile.
1/5 in an animal cell - contains genetic material that controls the activities of the cell.
Name two single celled microorganisms.
Yeast and Bacterial Cells
What is a partially permeable membrane?
A membrane with small gaps in it, which holds its structure, but allows small molecules to diffuse through it.
How is the sperm cell adapted to make sure it gets its DNA to the female DNA?
(swimming, 2, energy, and fusion)
It has a long tail and a stream lined head, to help it swim to the egg.
There are a lot of mitochondria in the cell to make sure it gets the energy it needs.
They carry enzymes in their heads to digest through the cell membrane.
What is diffusion?
Diffusion is the spreading out of particles from an area of high concentration to an area of low concentration.
What is differentiation?
Differentiation is the process by which cells become specialised for a particular job.
What affects the rate of diffusion down the concentration gradient?
Difference in concentrations
Surface area of the diffusion surface
A bacterial cell has ... and a cell ... surrounded by a cell ... . The genetic material floats in the ... because bacterial cells don't have a ... . Draw the bacterial cell.
A bacterial cell has cytoplasm and a cell membrane surrounded by a cell wall. The genetic material floats in the cytoplasm because bacterial cells don't have a nucleus.
How does the egg cell make sure the offspring get the right amount of DNA?
The membrane changes shape as soon as a sperm cell has fused with it. This stops any more sperm getting in.
2/3 in a plant cell - these are where photosynthesis occurs, which makes food for the plant. They contain a green substance called chlorophyll.
A yeast cell has a ... (containing genetic material), ..., and a cell ..., surrounded by a cell ... . Draw the yeast cell.
A yeast cell has a nucleus (containing genetic material), cytoplasm, and a cell membrane, surrounded by a cell wall.
What states does diffusion happen in?
Diffusion happens in both solutions and gases, because in these substances particles can move around more freely.
The bigger the difference in ... the faster the diffusion rate. When different gases diffuse through eachother, like when perfume is sprayed in a room.
The bigger the difference in concentration, the faster the diffusion rate.
3/5 in an animal cell - holds the cell together and controls what goes in and out.
What is haemoglobin?
What is missing in the cell to make room for more of this?
It is a pigment carried by red blood cells because it absorbs oxygen.
There is no nucleus to make more room for the haemoglobin.
So what are the guard cells adapted to do? (2 marks)
They are adapted to their function in...
1. allowing gas exchange
2. controlling water loss
within a leaf.
What are the advantages of the red blood cells' concave shape? (2)
1. Gives them a big surface area for absorbing oxygen
2. Helps them pass smoothly through capilleries to reach body cells.
1/3 in a plant cell - made of cellulose, it supports the cell and strengthens it.
Rigid cell wall
What happens to the specialised cells in systems etc?
What is 3 used for in large multicellular organisms?
The specialised cells form tissues.
A few of these form oragns.
A few of these form organ systems.
In large multicelluar organisms, there are different organ systems to exchange and transport materials.
Which cells are specially adapted for reproducing?
Sperm and egg cells, gemates.
What are organs made of? ... for example the stomach
A group of different tissues that work together to perform a particular function.
Why do partciles flow through the membrane?
How do they move?
Because on one side there is a high concentration and on the other, a low concentration.
They move randomly, but they spread to reach equilibrium.
What do specialised cells do?
They carry out a particular function.
When do guard cells do when the plant has lots of water?
The guard cells fill with water and go turgid, making them open so gases can be exchanged for photosynthesis.
How do dissolved substances move in and out of cells?
What size and type of molecules diffuse through cell membranes?
O, G, AA, W
S and P can't fit through.
Only very small molecules can diffuse through cell membranes.
Oxygen, glucose, amino acids, and water.
Bigger molecules like startch and proteins can't fit through the membrane.
What is a tissue formed of and what does it do?
Similar cells (not all the same specialised cell), that work together to carry out a particular function.
What do the guard cells do when the plant has little water?
The guard cells lose the water and become falccid, making the stomata close. This prevents too much water vapour escaping.
Give 3 examples of tissues in mammals... what do they do?
1. Muscular tissue... contract to move whatever it's attached to
2. Glandular tissue... makes and secretes chemicals, like enzymes and hormones
3. Epithelial tissue... covers some parts of the body e.g the inside of the gut
4/5 in an animal cell - these are where most of the reactions for respiration take place. respiration releases energy that the cells need to work.
5/5 in an animal cell - these are where proteins are made in a cell
What are red blood cells adapted for?
They are adapted to carry oxygen, and are an important part of the blood.
When does differentiation occur?
This occurs during the devlopment of the multicelluar organism.
What 3 tissues is the stomach (organ) made up of?
1. Muscular ... to chrun up the food
2. Glandualr tissue ... makes digestive juices to digest food
3. Epithelial tissue ... covers the outside and inside of the stomach
What is made up of organ systems?
Large multicellular organisms.
2/5 in an animal cell - gell-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions.
What is an organ systems, and what is it made of?
Organ systems are groups of organs working together to perform a particular function.
What are guard cells adapted to do?
What shape adaption does it have to do this?
Open and close pores.
Special kidney shape which openes and closes the stomata (pores) in a leaf.