Biology - Y10 mocks

What is the role of the stomata and guard cells?

What is the role of the stomata and guard cells?

To control gas exchange and water loss.

How and how often do bacteria multiply?

By simple cell division as often as every 20 minutes if they have enough nutrients and stay at stable temp.

What are monoclonal antibodies?

Identical copies of one type antibody

How are monoclonal antibodies produced?

1. A mouse is injected with chosen antigen

2. The mouse then produces specific lymphocytes

3. The lymphocytes are then removed from the mouse

4. These lymphocytes are fused with tumour cells

5. The hybridoma cell clones quickly

6. These clones release many identical antibodies which are collected and purified

Are monoclonal antibodies specific?

Monoclonal antibodies are specific to one binding site on one protein antigen.

They can therefore target a specific chemical or type of cell within the body.

Uses of Monoclonal antibodies

To treat some diseases

• For cancer the monoclonal antibodies can be bound to a radioactive substance,a toxic drug or a chemical which stops cells dividing

In research

• To locate or identify specific molecules by binding the antibodies to dye.

In laboratories

• Used to measure the levels of hormones and other chemicals in the blood.

Diagnosis

• In pregnancy tests they bind to hCG produced.

What is a risk factor?

Risk factors are something that can increase your risk for disease.

These can be

• aspect of someones lifestyle

• substances in the person’s body or environment

Risk factors for cardiovascular disease

• smoking

• high fat/cholesterol diet

• lack of exercise

Common risk factors

Smoking → lung disease/cancer and can cause tissue damage in unborn babies

Alcohol → liver damage and changed brain function,can cause premature birth and miscarriages

Carcinogens → can cause cancers (ionising radiation)

What are cells?

Cells are the basic building blocks of every living organism

What are sub-cellular structures in both animal and plant cells?

• Nucleus

• Mitochondria

• Cytoplasm

• Ribosomes

• Cell membrane

What are sub-cellular structures that only PLANT cells contain?

• Chloroplasts

• Cell wall

• Permanent vacuole

Function of the nucleus

Contains genetic material,DNA

Controls the activities of the cell

Function of mitochondria

Where aerobic respiration takes place

(provides energy)

Function of cytoplasm

Where most chemical reactions take place

It contains enzymes for this

Function of cell membrane

Controls the passage of substances in and out of the cell.

It contains receptor molecules.

Function of ribosomes

Where protein synthesis occurs

Uses RNA

Function of chloroplasts

These absorb light with chlorophyll and use this to complete photosynthesis.

This produces food.

Function of permanent vacuole

Filled with cell sap.

Used for storage and keeps shape of the cell

Function of cell wall

This supports the cell and strengthens it.

What is cellular respiration?

It is an exothermic reaction (transfers energy to the environment)

It is the process of transferring energy from glucose.

This is happening continuously in living cells.

The energy transferred allows all living processes to take place.

Where does aerobic respiration take place?

Mitochondria

What is metabolism?

It is the sum of all the chemical reactions in an organism

What does metabolism include?

• conversion of glucose to starch, glycogen and cellulose

• the formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids

• the use of glucose and nitrate ions to form amino acids which in turn are used to synthesise proteins

• respiration

• breakdown of excess proteins to form urea for excretion.

Stages of the cell cycle

INTER-PHASE

Sub-cellular structures replicate

DNA duplicates

MITOSIS

Chromosomes line up and are pulled apart to opposite poles.Two nuclei form.

CYTOKINESES

Cell membrane and cytoplasm divides.

What is produced from the cell cycle?

TWO daughter cells.

These are identical.

Why is cell division important?

It allows growth and development of multicellular organisms.

Muscle cells (animal cell)

Function: Contract and relax in order to move blood,skeleton or substances in the body

ADAPTATIONS

• Many mitochondria to produce lots of energy

• Special proteins that allow contraction

Sperm cell (animal cell)

Function: Male gamete.Carries genetic information from father to the egg

ADAPTATIONS

• Many mitochondria for energy

• Head has sac of specialised enzymes called acrosome which digest outer lining of egg cell

• Long tail to propel itself

• Nucleus containing genetic material

Nerve cell (animal cell)

Function: To transmit information as electrical impulses

ADAPTATIONS

• Long axon,carries impulses quickly

• Myelin,for insulation and speeds up impulses

• Branched endings,make many connections

Root hair cell (plant cell)

Function: Absorb mineral ions and water from the soil

ADAPTATIONS

• Large surface area for diffusion and osmosis

• Many mitochondria to provide energy for active transport

Xylem (plant cell)

Function: Transport water and mineral ions from the roots to the leaves of the plant.Also provides support.

ADAPTATIONS

• Made of dead hollow cells

• Walls contain lignin,waterproof and strengthening

Phloem (plant cell)

Function: Transport sugars throughout the plant

ADAPTATIONS

• Cross walls separating cells called plates

• Companion cells containing many mitochondria keeping other cell alive

What is osmosis?

The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

What can osmosis do to Red blood cells?

In dilute solutions,it can cause animal cells to swell up and burst.

This is called Lysis.

If there is a loss of water from osmosis the red blood cell will shrink.

What happens to a plant cell in pure water?

The cell contents push against the cell wall and the cell becomes turgid.

What happens to a plant cell in a salty solution?

The cell contents lose water by osmosis.They shrink and pull away from the cell wall.

The cell becomes flaccid.

What happens to a plant cell in a very salty solution?

The cell undergoes full plasmolysis as the cells lose more water.

What happens to a plant cell when the sugar content increases in a solution?

As the concentration of sugar increases so does the percentage change in mass.

How would you find the concentration of cell cytoplasm in the investigation of Osmosis?

It can be estimated by reading off the concentration of sucrose at the point where the line of best fit crosses.

What do digestive enzymes do?

They convert large food molecules into small soluble molecules that can be absorbed into the bloodstream.

What enzyme breaks down Carbohydrates?

Carbohydrases

What enzyme breaks down starch?

Amylase.

This is produced by your pancreas and salivary gland.

What enzyme breaks down protien?

Proteases.

What enzyme breaks down lipids?

Lipases.

Where does the glucose used in respiration come from?

From the digestive system.

What are the products of digestion used for?

To build new carbohydrates,lipids and proteins.

What happens in CHD?

Layers of fatty material build up inside the coronary arteries,narrowing them,reducing the blood flow and resulting in a lack of oxygen to heart cells.

What are statins?

They are drugs used to reduce the blood cholesterol level.This reduces the rate of build in arteries.

What are the pros and cons of Statins?

Pros

• reduce rate of build up

• decrease risk of heart attack

Cons

• Have side effects

• Have to be kept up with

What are stents?

They are metal mesh paced in an artery and then opened up by inflation of tiny balloon to hold a narrowed blood vessel open.

What are the pros and cons of Stents?

Pros

• No anaesthetic required

• Relatively cheap

Cons

• Ineffective against severely blocked or narrowed arteries

what are pathogens?

Microorganisms that cause infectious disease

What are the 4 types of pathogens?

Viruses,bacteria,fungi and protists

What pathogen is measles?

What are the symptoms of measles?

Virus

Symptoms

• fever

• skin rash

• cold-like symptoms

What is the transmission of measles?

What is the treatment for measles?

What is the prevention for measles?

1. Air droplets (sneezes)

2. Vaccination,antivirals

3. Vaccination

What is the pathogen of HIV?

What are the symptoms of HIV?

Virus

Symptoms

• fever

• diarrhoea

• weight loss

• swollen lymph nodes

What is the transmission of HIV?

What is the treatment of HIV?

What is the prevention of HIV?

1. Bodily fluids,normally with unprotected sex

2. No cure,antiviral drugs

3. Protected sex,no sharing of needles

What is the pathogen of TMV (tobacco mosaic v)?

What are the symptoms of TMV?

Virus

Symptoms

• leaves change from green to yellow

• leaves may crinkle/curl up

What is the transmission of TMV?

What is the treatment of TMV?

What is the prevention of TMV?

1. Contact

2. no cure

3. separate infected plants,hygeine

What is the pathogen of salmonella?

What are the symptoms of salmonella?

Bacteria

Symptoms

• vomiting

• diarrhoea

• abdominal cramps

What is the transmission of salmonella?

What is the treatment of salmonella?

What is the prevention of salmonella?

1. Unhygienic kitchens,under cooked food

2. Antibiotics

3. poultry vaccination,foods cooked properly

What is the pathogen of Gonorrhoea?

What are the symptoms of Gonorrhoea?

Bacteria

Symptoms

• burning pain when urinating

• thick yellow/green discharge

• infertility

What is the transmission of Gonorrhoea?

What is the treatment of Gonorrhoea?

What is the prevention of Gonorrhoea?

1. Sexually (STD)

2. Antibiotics

3. Contraception

What is the pathogen of RBS (rose black spot)?

What are the symptoms of RBS?

Fungus

Symptoms

• black/purple spots

• leaves turn yellow

• leaves drop off the plant

What is the transmission of RBS?

What is the treatment of RBS?

What is the prevention of RBS?

1. Air,water,contact

2. Fungicides,removing and destroying dead/infected leaves

3. Removing infected plants

What pathogen is Malaria?

What are the symptoms of Malaria?

Protist

Symptoms

• fever

• sweats/chills

• headaches

• vomiting

• diarrhoea

What is the transmission of Malaria?

What is the treatment of Malaria?

What is the prevention of Malaria?

1. Mosquitoes (vector)

2. Antimalarial drugs

3. Don’t get bitten,vaccination

How do vaccines work?

1. Vaccines are a dead or inactive pathogen

2. Lymphocytes clone and produce antibodies

3. Some lymphocytes develop into memory cells

4. If this pathogen infects in the future the response is

   FASTER

   LARGER

   LONGER LASTING

What happens in Phagocytosis?

1. Phagocyte engulfs the pathogen

2. The pathogen is digested

3. These broken down materials diffuse out

What do antibodies do? (the proccess)

1. Lymphocyte detects non-self antigen and releases antibodies

2. The antibody binds to the antigen with the complementary shape

3. Many pathogens and antibodies are bonded.This is agglutination.

What do antitoxins do?

1. Lymphocyte detects toxins and releases antitoxins

2. These neutralise the toxins

What happens to a plant during a Nitrate deficiency?

Stunted growth

Nitrate is needed for protein sythesis

What happens to a plant during a Magnesium deficiency?

Chlorosis(loss of green colour)

Magnesium ions make chlorophyll

What are some physical defences from plants?

• Cellulose wall

• tough waxy cuticle

• bark

• leaf fall

What are mechanical defences of plants?

• Thorns/hair

• leaves which drop/curl when touched

• Mimickrey

What are chemical defences of plants?

• antibacterial chemicals

• poisons

What is the structure in the cross-section of a leaf?

1. Waxy cuticle

2. Upper epidermis

3. Palisade cells

4. Spongy cells including vein with phloem and xylem and air spaces.

5. lower epidermis including guard cells and stomata

What is the equation for photosynthesis?

carbon dioxide + water  →  glucose + oxygen

6CO2+6H2O→C6H12O6+6O2

What might the glucose produced in photosynthesis be used for?

• respiration

• storage by being converted to starch

• to produce lipids for storage

• to produce cellulose and strengthen cell wall

• used to produce amino acids for protein synthesis

What is the method for testing for sugar?

1. Set up heating apparatus and bring half a beaker of tap water to boil.

2. Place a small amount of food into a test tube and add enough benedicts solution to completely cover it.Place the test tube into the beaker of hot water.

3. Leave the test tube in the hot water and record any colour change after two min.

4. If high conc. blue → red

   Low conc. blue → green/yellow

What is the method for testing for protein?

1. Place a piece of food into a test tube.

2. Add sodium hydroxide solution using a dropping pipette so the food is completely covered.

3. Add an equal amount of copper sulphate solution.Shake the tube gently.

4. Leave the tube in a test tube rack.This will allow any colour change to develop before it is recorded.

5. Protein is present if blue →lilac/purple

What is the method for testing for starch?

1. Place a small amount of food into a dimple on the spotting tile.

2. Add a few drops of iodine solution to that dimple.

3. Record any colour change that takes place after 1 min.

4. Present if orange → blue

What is the method for testing for fats?

1. Place a piece of food into a test tube.

2. Add ethanol so the food is completely covered.

3. Place your thumb over the top of the test tube and shake for 10 seconds to allow time for any fat within the food to dissolve.

4. Add water to a clean test tube so it is 1/3 full.Decant the ethanol into the water.

5. If it changes from colourless → white then fat is present.

What effect does light intensity have on the rate of photosynthesis?

As the light intensity increases so does the rate of photosynthesis.

What effect does temperature have on the rate of photosynthesis?

As temperature increases so does the rate of photosynthesis.

However after a certain temp enzymes denature and therefore the rate decreases.

What effect does carbon dioxide concentration have on the rate of photosynthesis?

An increase in concentration causes an increase in the rate of photosynthesis.

What effect does the amount of chlorophyll have on the rate of photosynthesis?

Large amounts of chlorophyll means an increased rate of photosynthesis.

Describe the process of transpiration.

1. The concentration of water inside the root hair cell is normally lower than in the soil

2. Water flows into the root hair cell by osmosis

3. Many mineral ions are absorbed from the soil along with the water against the concentration gradient.This process requires energy and is known as active transport.

4. Water diffuses from the root hair into the xylem tubes at the centre of the root.

5. Water flows from the roots to the stem and then to the leaves

6. Water passes out of the xylem tubes into the leaf cells via osmosis

7. Water evaporates from the cell walls into the air spaces within the leaf

8. Water vapour diffuses out of the leaf via the open stomata.

What is the effect of changing temperature on the rate of transpiration?

As temperature increases so does the rate of transpiration

This is because it means there is more kinetic energy and faster evaporation.

What is the effect of changing humidity on the rate of transpiration?

As humidity increases the rate of transpiration decreases.

This is because there are more water molecules in the air and so the concentration gradient is reduced.

What is the effect of changing air movement on the rate of transpiration?

Increased movement of air will increase the rate of transpiration.

What is the effect of changing light intensity on the rate of transpiration?

Increasing light intensity will increase the rate of transpiration.

What is translocation?

Transport of dissolved sugars from leaves to all other plant cells.