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
Whats the function of cappilaries?
To allow organs to exchange substanves with the blood
What makes cappilaries different from other vessels?
Only has a one cell thick permeable outer wall
What do veins have that arteries dont?
Valves
Whats the actual name of the shape of a blood cell and why is it this shape?
Biconcave disk gives a large surface area
What does haemoglobin binded with oxygen make?
Oxyhaemoglobin
What is carried in plasma?
Red and white blood cells and platelets
Nutrients
Carbon dioxide
Urea
Hormones
Proteins
Antibodies
What is thrombosis?
A blood clot developed due to a stent
What do statins do?
Reduce cholesterol in the blood
Advantages of statins
Reduce chd and stroke risk
Increase amounts of beneficial cholesterol
Reduce amounts of bad cholesterol
Could help prevent other diseases
Disadvantages of statins
Long term drug that has to be taken regularly
Sometimes causes negative side effects
Non instant effect
What major factors affect your health?
Disease
Diet
Stress (mental health)
Life situation (money, location, availability of items)
What risk factors could directly cause disease?
Smoking
Obesity
Alcohol abuse
Pregnancy smoking or drinking
Carcinogens
What causes cancer? (Directly)
Uncontrolled cell growth and division
Def benign
Tumor has grown but isnt spreading and and usually isnt dangerous
Ded malignant
Tumor grows and spreads and invades healthy tissues. Malignant tumors are cancers. They can be fatal.
What lofestyke factors increase your chance of catching cancer?
Smoking - mainly lung cancer
Obesity
UV exposure - skin cancer
Viral infection - Hepatitis B or C (liver cancer)
Examples of tissues that make up a plant
Epidermal tissue - covers the plant
Palisade mesophyll
Spongy mesophyll
Xylem and Phloem
Meristem tissue
See page 39 of the CGP guide for full diagram
What does the waxy cuticle do?
Helps prevent water loss by evaporation
What does the upper epidermis do?
Its transparent so light can pass into the palisade layer
What is the palisade layer for?
Has lots of chloroplasts. Near to top of leaf for most light too.
How is the leaf structured to optimise gas exchange? (2)
Lower epidermis is full of stomata.
Spongy mesophyll contains air spaces to increase diffusion rate.
What is translocation?
The movement of food substances through the phloem of a plant.
What is the transpiration stream?
The movement of water and mineral ions through the xylem from the roots to the leaves and stem of a plant
What is transpiration?
The loss of water from a plant
What are the four main factors that affect transpiration?
Light intensity - the brighter the light, the greater the rate of transpiration
Temperature - the warmer it is, the faster transpiration happens
Air flow - the more wind there is, the faster water vapour is carried away from a leaf
Humidity - the drier it is, the faster transpiration happen
How do stomata open and close?
They either gain or lose water to become turgid or flacid. Enabling gas exchange
What is a protist?
A single - celled eukaryote
What are some fungi made of and what can they do?
Hyphae - which can penetrate skin or plants causing diseases.
What 3 ways can pathogens be spread?
Water - eg cholera
Air - eg influenza
Contact - eg athletes foot
Give examples of 3 viral diseases
Measles
HIV
Tobacco mosaic virus
What is measles? (Symptoms, results, treatment)
A viral disease spread by infected drops in sneezing or coughing
Measles causes a skin rash and signs of a fever
Measles can be fatal
Most people are vaccinated against measles from a young age
What is HIV? (Symptoms, results, treatment)
HIV is a virus spread by sexual contact or bodily fluid exchange such as blood.
HIV causes flu symptoms for a few weeks, but then nothing
The virus attacks the immune cells and can lead to AIDS
The virus can be controlled with antiretrovial drugs but not cured.
What is TMV?
Virus that affects plants eg tomatoes
Causes a mosaic pattern on plant leaves
Prevents photosynthesis (mostly)
Example of a fungal disease
Rose black spot is a dungal disease that can cause a plant to lose leave and not photosynthesise. It spreads through water or wind and can be treated with fungicides.
Example of a disease caused by a protist
Malaria is a disease caused by a protist carried by mosquitoes. Malaria causes repeated episodes of fever and can be fatal. You can use insecticides to protect yourself.
2 examples of bacterial diseases
Salmonella
Gonorrhoea
What is salmonella? (Symptoms, treatment)
Salmonella is a bacterial infection that causes food poisoning. Infected people have a fever, cramps, vomiting and diarrhoea.
What is gonorrhoea?
Gonorrhoea is a sexually transmitted infection caused by bacteria. It causes pain in urination and yellow or green discharge from the genitals. It can be treated with antibiotics or prevented with barrier methods of intercourse.
How can the spread of disease be prevented / reduced
Being hygenic
Destroying vectors
Isolating infected individuals
Vaccination
What defence mechanisms does the human body have?
The skin is a barrier against disease
Hairs and mucus in your nose
Trachea and bronchi secrete mucus
Trachea and bronchi are filled with cilia
The stomach produces hydrochloric acid
What is the process called whn white blood cells engulf foreign cells?
Phagocytosis
What 3 ways can our immune system attack pathogens?
Consuming them
Producing antibodies
Producing antitoxins
What is the name of the white blood cell that produces antibodies?
B - lymphocyte
Pros of vaccination
Help control communicable diseases.
Big outbreaks can be prevented if large populations are vaccinated
Cons of vaccination
They dont always work
You can sometimes have a bad reaction to them
What are the three main stages in drug testing?
- Test the drug on cells or tissue in the lab
- Test the drug on live animals to find info about toxicity and dosage
- Test the drug on human clinical trials, first healthy, then ill blind tests with placebos
Is photosynthesis exothermic or endothermic?
Endothermic
What ways do plants use glucose?
For respiration
To make cellulose for cell walls
Making amino acids when combined with nitrate ions for proteins
Stored as oils or fats for storage in seeds
Stored as starch as it is insoluable
Why is it important for plants that starch is insoluable?
Starch is insoluable so its better for storing as unlike glucose which will cause a cell to draw in water and swell up
What temperature do enzymes used in photosynthesis usually denature at?
45 degrees
How can you measure the rate of photosynthesis?
By measuring the amount of oxygen produced. Pondweed test
Which law links light intensity and distance?
The inverse square law
What is the formulae for light intensity?
1/d2 (1 over d squared)
How can farmers optimise plant growth?
Grow the plants in a greenhouse
Supply light to the plants at night
Use a paraffin heater to increase carbon dioxide concentration
Keep the plants guarded from pesticides and disease
Define respiration
Respiration is the process of transferring energy from glucose which goes on in every cell
Is respiration exothermic or endothermic?
Exothermic
Give 3 examples of how organisms use energy transferred by respiration
To make larger molecules
To contract muscles
To regulate body temperature
Def metabolism
Metabolism is the net amount of reactions taking place in an organism
How is anaerobic respiration in plants and yeast different?
It converts glicose to ethanol and carbon dioxide.
Why is anaerobic respiration in yeast cells (fermentation) useful?
It can be used to create bread and alcoholoc drinks. The carbon dioxide makes bread rise and the fermentatiom process produces alcohol for beer and wine making.
What happens to lactic acid?
It is taken to the liver and is converted back to glucose.
How can you investigate the effect of exercise on the body?
Test your breathing rate when in exercise, rest, after exercise and in heavy exercise.
