Biology Paper 1 GCSE Exam Flashcards
Which cells can you find a cell wall in?
Plant Cell
Bacterial Cell
Which cells can you find a cell membrane in?
Plant Cell
Animal Cell
Bacterial Cell
Which cells can you find a nucleus in?
Plant cell
Animal Cell
Which cells can you find a cytoplasm in?
Plant Cell
Animal Cell
Bacterial Cell
Which cells can you find a Ribosomes in?
Plant Cell
Animal Cell
Bacterial Cell
Which cells can you find a mitochondria in?
Plant Cell
Animal Cell
Which cells can you find a chloroplasts in?
Plant Cell
Which cells can you find a vacuole in?
Plant Cell
Which cells can you find a flagella?
Bacterial Cell
Which cells can you find a Plasmid?
Bacterial Cell
How do you calculate the magnification?
Image height / Object height
What is 1 micrometre in mm?
0.001
What is 1 nanometre in mm?
0.000000001
What is the advantage of a light microscope?
Easy to use and inexpensive
What are the advantages of a electron microscope?
Can see smaller thing and more detail. It also has a higher resolution and magnification
What is the resolution of an electron microscope?
1 nanometer
What does magnification mean?
The act or process of enlarging the physical appearance or image of something.
What is a specialised cell?
A cell which is adapted to carry out a particular function
What happens when a cell differentiates?
It acquires different sub-cellular structures to enable it to carry out a certain function.
What are some examples of a specialised cell?
ciliated cell Xylem cell nerve cell sperm cell root hair cell phloem cell red blood cell muscle cell
What is the function of a sperm cell and how is it adapted?
Head contains genetic information and an enzyme to help pentrate the egg cell membrane and fertilise the egg.
What is the function of a root hair cell and how is it adapted?
Has long fingers which gives it a large surface area which helps absorb water and mineral irons from the soil
What is the function of a ciliated cell and how is it adapted?
Has a tiny thin layer of tiny moving hairs called cilia which push and move mucus from one place to another
What process do cells use oxygen?
Respiration
How does the mitochondria in a sperm help it to swim>
It releases energy so it can swim
Why does a bacterial cell not contain mitochondria?
There is not enough room in a bacterial cell
Why is a leaf cell specialised to carry out photosynthesis?
It has many chloroplasts
Put this in order of size from the smallest to the largest: Chromosome nucleus gene cell
Gene
Chromosome
Nucleus
Cell
What are chromosomes made out of?
Small sections called genes
What is a stem cells?
An undifferentiated cell
When can embryonic stem cells be collected an what can they develop into?
Can be collected from early embryos and can develop into any type of cell
What happens after the egg and the sperm meet?
They form a zygote then divide using mitosis
Where does adult stem cells come from and what can they develop into?
Can be collected from adult bone marrow and can develop into many but not all types of cells
What are some arguments against stem cells?
An embryo is a human so it has human rights
Murder is just wrong
Killing an embryo at any age is as wrong as killing a child or an adult
Creating embryos for medical treatment is wrong. It’s creating a life which is then destroyed
What are some arguments for stem cells?
Can cure many diseases including making new brain cells for parkinsons
rebuild bone and cartialage
If it was for you or a friend and it was the only way you could get better you wouldnt be against it
Research on embryos is legal up to 14 days and if something is legal it cant be wrong
What does a cell need to do before it divides?
Replicate the DNA and increase the number of sub cellular chromosomes like ribosomes and mitochondria
Where does mitosis take place?
Any body cell
How many cell divisions are there in Mitosis?
1
How many daughter cells are produced in mitosis?
2
Are the daughter cells in mitosis genetically identical or different?
identical
Why is mitosis important?
Cell replacement
Growth
Does the daughter cells have the same number of chromosomes compared to the parent cell?
yes
What type of molecules can diffuse?
Gases
Liquids
What is the definition of diffusion?
Spreading out of particles of a gas or dissolved molecules from a high concentration to a low concentration. Molecules diffuse down a concentration gradient.
What are two factors which increase the rate of diffusion?
Temperature
Concentration difference
Surface area of the membran
Why do living things need oxygen?
Respiration
What is the surface area like of a single celled organism compared to volume ratio?
Has a relatively large surface area to volume ratio. This allows sufficient transport of molecules into and out of the cell
What is the surface area like of a multicellular organism compared to volume ratio?
Small surface area to volume ratio means they have developed exchanges surfaces that are specialised for exchanging materials
What gases are exchanged in the lungs?
Oxygen
Carbon Dioxide
Where in the lungs does exchange take place?
Alveoli
How is the alveoli stucture adapted for rapid gas exchange?
Large Surface Area
Its thin creating a short diffusion pathway
Ventelation to maintain a difference in concentration
efficient blood supply
What substances are exchanged in the small intestine?
Nutrients are absorbed into the blood
How is the small intestine for rapid exchange?
Large surface area
Thin cell wall so short diffusion pathway
Efficient blood supply
How are the gills in a fish adapted?
Large surface area
Thin creating a short diffusion pathway
efficient blood supply
How is the root adapted for rapid exchange?
Large Surface Area
Thin creating a short diffusion pathway.
How does minerals enter a root hair cell?
Active transport
How does active transport work?
When substances move into cells from low to high concentration. It needs energy to make it happen which is released in respiration.
How is active transport used in the gut?
Allow sugar molecules to be absorbed from lower concentrations in the gut into the blood which has a higher sugar concentration
What is osmosis?
Osmosis is the movement of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane.
Which type of movement requires energy from respiration?
Active Transport
What vegetable could be used to investigate osmosis?
Potato
How do you do the potato experiment to observe osmosis?
- Label 6 boiling tubes with each sugar concentration (0M, 0.2M, 0.4M….1M)
- Measure out 10cm3 of each sugar solution and place into correct boiling tubes
- Using a cork borer, cut six potato cylinders of the same diameter
- Trim the cylinder so that they are all the same length
- Accurately measure and record the length and mass of each potato cylinder before placing into boiling tubes
- Leave cylinders in boiling tubes over night
- Remove one of the cylinders from the boiling tubes and carefully blot dry with the paper towels
- Re-measure the length and the mass and record in your table
- repeat with the remaining cylinders
What would you have found out after using the potato cylinders to observe osmosis?
As the sugar concentration increase the change in mass decreases. At a sugar concentration of 0.25m there is no change in mass
How can you explain what has happened to the potato cylinders?
At a concentration of 0m sugar solution the mass of the potato cylinder increases because water has moved into the potato. The potato becomes turgid.
At a concentration of 1m sugar solution the mass decreases because water has moved out. The potato has become flacid
What is a stem cell?
An undifferentiated cell
What would happen if you got stem cells from someone else?
The immune system would recognise the cell as foreign and they would be rejected and die
What is therapuetic cloning?
They take a nucleus out of a human egg cell then they would put the nucleus from the patients cell into the egg cell. The egg cell then stimulates to develop an embryo and then the stem cells are taken from the embryo. The stem cell is then grown in a container of warm nutrients and then treated to develop into required cell types.
What are plant meristem cells?
unspecialised stem cells in plants grouped together in structures
How are plant stem cells different to animal stem cells?
Animal stem cells stop growing in size once they become adults but plants continue to grow
How can we use meristem cells advantageously?
produce clones of plants quickly and economically. This means rare species can be cloned to protect them from extinction
What is the function of the stomata?
Carbon dioxide in
Oxygen out
Controls water loss
What would happen if you put red blood cells into water?
Water will diffuse in and cells will swell and burst
What is the definition of a tissue?
group of cells with similar structures and function
What is an organ?
A collection of tissues performing a single function
What is an organ system?
A group of organs working together to perform a function
Which tissue types have the stomach adapted to enable it to carry out its function?
Muscular - contracts bringing about movement
Glandular - produces substances such as enzymes and hormones
Epithelial - Cover some parts of the body
What are enzymes?
enzymes speed up chemical reactions in your body otherwise they would take place to keep you alive
What are 4 properties of enzymes?
Biological catalysts
cannot be used up
made from protein
They are specific they will only catalyze one reaction
What are catalysts?
Increases the rate of a chemical reaction without being used up or changed
What does the lock and key theory state?
It stated that a reaction to take place the substrate much fit perfectly into the active site of the enzyme. This means that enzymes are specific and will only bind with one type of substrate.
What does denature mean?
The shape of the active site has changed
Where is Amylase produced and what is its substrate and product?
Its produce in the: Salivary gland small intestine pancreas The substrate is starch and glucose is its product
Where is Protease produced and what is its substrate and product?
Produced in the: Small Intestine Pancreas Stomach The substrate is protein and amino acids it its product
Where is Lipase produced and what is its substrate and product?
Produced in the:
Pancreas
Small intestine
The substrate is lipids and fatty acids and glycerol are its products
What is digestion?
The process of food being broken down through your body using either mechanical digestion or enzymes
Why do we have enzymes to digest our food?
Speed up the break down of the food in the amount of time needed to keep us alive. The reaction would take place too slowly without
What happens to the products of digestion?
Absorbed by the small intestine into the blood strean
What type of digestion happens in the mouth?
Mechanical
What enzyme is produced in the salivary glands?
Amylase
What type of digestion happens in the stomach?
mechanical
What does stomach acid create?
The acidic conditions needed for protease to work
What does bile do?
Bile emulsifies large fat molecules to form small droplets
Why does bile neutralise food?
To create the alkaline conditions needed for enzymes in the small intestine to work
How do you test for sugars?
- grind up food and place in a beaker with distilled water
- stir so food dissolves and filter
- fill half the test tube with the solution and add 10 drops of benedicts solution
- put hot water in a beaker and place test tube in it
- If sugar is in it it should turn green, yellow, or brick red
How do you test for Starch?
Add a few drops of iodine solution to the food solution and if starch is present it should turn black or a blue-black colour
How do you test for Lipids?
- grind up the food sample and place into a beaker with distilled water
- stir mixture so food dissolves but do not filter
- fill half of the test tube with the solution
- add 3 drops of Sudan III stain to the solution and shake gently to mix
- If fat is present a red stained layer will seperate out and float on the water surface
How do you test for proteins?
- grind up the food sample and place into a beaker with distilled water
- stir mixture so food dissolves and filter
- fill half of the test tube with the solution
- add 2cm3 of biuret stain to the solution and stir
- If protein is present it should turn the solution pink or purple
What does the optimum temperature show?
The temperature the enzyme works best at
How do you investigate the effect of pH on the enzyme amylase?
- Place one drop of iodine solution into each depression on the spotting tile
- Label three test tubes with pH 4, 7 and 10
- Measure out 5cm3 of starch solution, using the measuring cylinder or syringe, into 3 test tubes
- Measure out 5cm3 of each buffer solution and add to appropriate test tube
- Place test tube of starch solution at pH 4 into a water bath of 37c
- Measure out 1cm3 of amylase solution, using a measuring cylinder into a test tube and place in water bath
- leave test tubes in the water baths until the contents of each tube have reached temperature of water baths
- Once they’ve reached required temperatures carefully pour amylase solution into the test tube with the starch solution and mix with glass rod
- Remove one drop of mixed solution on the end of the glass rode and place on first depression of the spotting tile with the iodine solution
- Immediately start time
- using glass rod remove one drop every minute and place into iodine solution in the next depression rinse glass rod with water after each drop
- continue until iodine solution no longer turns black this indicates starch has been broke down
- repeat for pH 7 and pH 10
What happens as the pH level gets further away from the optimum?
enzyme activity decreases
What is the epidermal tissue?
Covers the outside of the plant a single layer of cells that don’t contain chloroplasts