GCSE PAPER 1 Flashcards
What does the permanant vacuole do?
Contains cell sap. A sugar and salts solution
What dont bacteria cells have?
A casing for the dna
Chloroplasts
Mitochondria
What is the process called where a cell changes to become specialised?
Differentiation
What is an undifferentiated cell called?
A stem cell
Give 5 examples of specialised cells and some examples of their specialisations.
Sperm cells - lots of mitochondria, long tail and streamlined head, enzymes in head
Nerve cells - long, have lots of branched connections
Muscle cells - long (so have space to contract), lots of mitochondria for the energy needed
Root hair cells - big surface area
Phloem and xylem - xylem are hollow. Phloem have few subcellular structures.
What are the two main parts of the cell cycle
Growth and DNA replication
Mitosis
What happens at the growth and dna replication stage of the cell cycle
The cell increases the number of subcellular structures and dublicates its dna so there is a copy for each new cell.
Describe what happens in mitosis
- The chromosomes line up in the centre of the cell
- The chromosomes a cut in half and go to opposite ends of the cell
- Membranes form around the new chromosomes. These are the new nuclei.
- The cytoplasm and cell membranes divide
Whats the difference between embryonic and normal stem cells?
Embryonic stem cells can become ANY cell but normal ones can only become certain cells like blood cells.
What can stem cells be used for today?
They can be cloned in a lab to create undifferentiated cells.
Embryonic stem cells can be given to sick people to repair damage such as to male insulin producing cells in a diabetic person. Or replace nerve endings in a paralyzed person.
Why are some people against stem cell research?
They feel human embryos shouldn’t be used for experiments since each one is a potential new life.
Why are some people for stem cell research?
Unwanted embryos are usually destroyed by the clinic anyways.
They believe curing people who are suffering is more important than the right of the embryo.
How are stem cells in plants different to animals?
Stem cells in plants can differentiste into any cell throughout the plants entire life.
Def diffusion
The spreading out of particles from an area of high concentration to an area of low concentration.
What is the concentration gradient?
The difference in concentration
How can you increase diffusion rate without increasing concentration?
Increase the temperature.
What does active transport need to work and how is this affected by processes in the plant?
Active transport needs energy to transfer mineral inoms from a low concentration to high concentration. Increasing the rate of respiration can increase the rate of active transport.
How are exchange surfaces adapted?
They have a Thin membrane for a short diffusal distance
In animals, lots of blood vessels are there so transport to blood is faster
Gas exchange surfaces are often ventilated
They have a Large surface area so more substance can diffuse at once
Where does gas exchange take place in the lungs?
Alveoli
What adaptations do alveoli have?
Very large surface area
Moist lining for gas dissolving
Thin walls
Good blood supply
What are villi?
Tiny projections in the small intestine that increase surface area
How are leaves adapted for gas exchange? (5)
The underside of the leaf is covered in stomata
Oxygen and water vapour can diffuse through the stomata
The size of the stomata is controlled by guard cells to regulate water loss
The flat shape increases surface area
Air spaces inside the leaf increase SA so more carbon dioxide echange can happen
How are gills specialised for gas exchange?
Gill filaments have a large surface area and are covered in lamellae which increase SA even more.
Lamellae have lots of cappilaries and a thin surface layer of cells to speed up diffusion
The concentration of oxygen is always higher in the water so as much diffusion as possible can happen at once.
Give 3 examples of tissues seen in mammals.
Muscular tissue
Glandular tissue - makes and secretes chemicals
Epithelial tissue - covers parts of the body like the gut
Define catalyst
A substance that increases the speed of a reaction without being changed or used up in the reaction.
What are enzymes and what are they made of?
Biological catalysts
Proteins
Whats the calculation for rate of reaction?
1000 / time taken
Whats the name for a type of enzyme that breaks down carbohydrates?
Carbohydrase
Whats the name for a type of enzyme that breaks down protein?
Protease
Whats the name for a type of enzyme that breaks down lipids?
Lipase
Where is amylase made?
Salivary glands
Pancreas
Small intestine
Where are proteases made?
Stomach (pepsin)
Pancreas
Small intestine
Where are lipases made
Pancreas
Small intestine
What dies bile do?
Neutralises acid and emulsifies fat
Name the glands (and other organs) where enzymes are produced
Salivary glands
Stomach
Liver
Pancreas
Gall bladder
Small intestine
What food could you use in the benedicts test?
Bread
What food could you use in the iodine test?
Pasta / rice
What food could you use in the biuret test?
Meat / cheese
What food could you use in the ethanol test?
Milk
Name all the parts of the lungs
Diaphragm
Ribcage
Pleural membranes (surround the lungs)
Trachea
Bronchi (plural of bronchus)
Bronchioles
Alveoli
Whats the name of the hole in the middle of a blood vessel?
The lumen