Biology Paper 1 HMW Flashcards
Three Advantages of using an electron microscope over a light microscope.
Higher magnification/resolution
Ability to observe internal structures in detail due to electron beam shorter wavelength
Capability to study, nonliving, specimens as electron microscopes use a vacuum 
Eight features found inside a eukaryotic cell and their importance
Nucleus: contains genetic material, controls cell activities
Mitochondria: site of cellular respiration, produces energy
Plasmid: involved in protein and lipid synthesis
Ribosome: site of protein synthesis
Cell membrane: regulates the passage of substances in and out of the cell
Cell wall: providing structure
Cytoplasm-shape/storing molecules,
Vacuole -storage space 
Three structures unique to a prokaryotic cell and the function
Chloroplasts-chloroplast contain chlorophyll, and are the site of photosynthesis
Cell wall-made from Celulose and it strengthens the cell
Vacuole-storing important nutrients
Explain how the unique features of a sperm cell relate to their function
The function of a sperm is to get the male DNA to the female DNA. It has a long tail and a streamlined head to swim to the egg. There are lots of mitochondria in the cell to provide energy needed. It also carries enzymes in its head to digest through the egg cell membrane. 
Explain how the unique features of a root hair cell relate to their function
Root hair cells the cells on the surface of plants, which grow into long hairs that stick out into the soil. This gives the plant a big surface area for absorbing water and mineral oils from the soil 
Identify three factors that increase the rate of diffusion
Higher Temperature
Pressure
Concentration gradient
State, the full definition of osmosis
Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration 
Describe an example of a species using active transport. Why is it used and what benefit does it bring?
Root hair cell
Minerals should move out of the root hair cells if they follow the rules of diffusion.
Active transfer allows a plant to absorb minerals from a very dilute solution against a concentration gradient. This is essential for its growth. But active transport needs energy from respiration to make it work 
Name four body parts found in plants and animals that are specialised exchange surfaces
Alveoli-an enormous surface area, a moist lining for dissolving gases, very thin walls, a good blood supply
The villi -good blood supply to assist quick absorption, a single layer of surface cells 
Gills-is water enters the fish through its mouth and passes out through the girls. As this happen, oxygen defuses from the water into the blood in the girls and carbon dioxide diffuses from the blood into the water.
The structure of leaves -stomata 
What happens in each of the three main stages of the cell cycle?
Interphase-the cell get ready to divide
Mitosis-the genetic material separate to 2 different ends of the cell, and this I’ll get ready to divide into two daughter cells
Cytophase-the cytoplasm and cell membranes split and two daughter cells are made
Compare stem cells found in animals to the meristem cells found in plants
Meristem-origin of unspecialised cells in plants that are capable of cell division. They have the potential to become any type of specialised cell.
Adult stem cells have a function to replenish differentiated cells that needs to be replaced. They can only produce cells that are differentiated.
Why do embryonic stem cells have a wide range of potential medical uses?
Embryonic cells that are undifferentiated can become any cell in the body. This allows embryonic stem cells to be used to generate a repair diseased tissue. An organ is.
How might therapeutic cloning be the key to many medical treatments in the future?
Therapeutic cloning will bring enhance possibilities for organ, transportation, nerve cells and tissue healing
Identify three different tissues found in the stomach and explain how each aid digestion
Muscular tissue- to turn the food and digestive juices of the stomach together
Glandular tissue-to produce the digestive juices that break down food
Epithelial tissue-which covers the inside and the outside of the organ 
Identify the role of the mouth, stomach, liver, pancreas, small, and large in testing during digestion
Mouth-churn up food into smaller pieces
Stomach- how old is the food and mix it with an acid and enzymes that continue to break the food down into a liquid
Liver-produces bile to break down lipids
Pancreases-produces protease, which breaks down protein
Small intestine-absorbs, nutrients and water from the food to be used in the body
describe how foods can be tested to identified the presence of starch, glucose, lipids, and proteins
sugar-benedict’s solution
heat in water bath
turns red-brown
wear safety goggles
benedict’s is irritant
avoid contact with skin/eyes
starch-iodine
dimple tile
turns blue-black
wear safety googles
iodine is irritant
avoid contact with skin/eyes
proteins-biuret
add to test tube,mix
fats-sudan iii
equal amount of food and water added to test tube, drops of Sudan and shake
red stained layer forms 
explain the lock and key theory how enzymes work
The lock and key theory is a simple model of how enzymes work. The substrate of the reaction to be catalysed fits into the active side of the enzyme. You can think of it like a lock and key once it’s in place the enzyme subject buying together the action then takes place rapid and the products are released from the surface of the enzyme 
What are the substrates and products of carbohydrase, lipase and protease enzymes?
carbohydrase-complex carbohydrates such as starch and cellulose are made up of long chains of simple sugar unit bonded together
lipase-made up a free molecules of fatty acids joint to a molecule of glycerol
protease-long chains of small units called amino acids through 20 different amino acids

identify two significant roles of bile in adding digestion
Where is it made ,stored and released?
emulsifies the fats in your food this means bio physically breaks up large drops of fat into smaller droplets so the lipids enzymes have a bigger surface area to act upon
neutralises the acid that was added to food in the stomach. This provides the alkaline conditions necessary for enzymes in the small intestine to work most effectively
made-liver
stored-gall bladder

What are the four main parts of our blood and what role does each part have?
red blood cells -biconcave discs-increase surface area to volume ratio for diffusion, packed with haemoglobin that binds to oxygen, they have no nucleus making more space for haemoglobin
plasma-yellow liquid that transport all of your blood cells and some other substances around the body
Platelets -small fragments of cells, they have no nucleus, they help blood heart a site of a wound
White blood cells -much bigger than red blood cells , there are fewer of them, they have a nucleus and part of the bodies defence system against harmful microorganisms
Describe the key structural features of veins, arteries, and capillaries
arteries -carry blood away from the heart the organs of your body, thick walls, elastic fibres
Veins -carry blood away from the organ to your heart, low in oxygen, no pulse, thinner walls, have valves to prevent backflow
Capillaries -huge network of tiny vessels linking the arteries and the veins, very thin walls which allows substances such as oxygen and glucose to diffuse easily out of your blood and into your cells 
State the sequence of vessels and chambers the heart passes through inside a heart
The two sides of heart fill an empty at the same time, giving a strong, coordinated heartbeat.
Blood into the top chambers of your heart which are called the atria.
The blood coming into the right atrium from the vena cava is deoxygenated blood from your body.
The blood coming into your left atrium in the pulmonary vein is oxygenated blood from your lungs.
The atria contract together and fast blood down into the ventricles.
Valves closed to stop the blood flow backwards out of the heart 
how can a blockage in the Connery artery be caused what medical treatments can be used?
A common cause is the buildup of fatty material on the lining of the vessels. If the blood flow through the Conry artery is reduced, the supply of oxygen to the heart muscle is also reduced.
Stent is a metal mesh that is placed in the artery. A tiny balloon is inflated to open up the blood vessels and the stent at the same time. The balloon is deflated and removed but the stent remain in place 
describe and explain four adaptations of the alveoli that allow efficient gas exchange
there is clusters of alveoli that provide a large surface area which is important for achieving the most effective diffusion of oxygen and carbon dioxide
there is a rich supply of blood capillaries which maintains a concentration gradient in both direction
gas exchange takes place down the deepest concentration gradient possible which makes the exchange rapid and effective
Layer of cells between the air in the lungs and the blood in the Cys is very thin which allows diffusion to take place over the shortest possible distance 
How are xylem vessels in a plant perfectly suited for transporting water and minerals?
Structure – stacked, Dead Hollow cells, lined with Lignin to form a strong tube
Function -transporting sugars from leaves to the other plant tissues
How are xylem vessels in a plant perfectly suited for transporting water and minerals?
Structure – stacked, Dead Hollow cells, lined with Lignin to form a strong tube
Function -transporting sugars from leaves to the other plant tissues
How is the palisade mesophyll perfectly suited for optimal photosynthesis 
Structure-a tightly packed layer of cells,full of chloroplast
What is transpiration and what factors make transpiration happens most quickly
Transpiration is the process of water loss from plants through this tomato into the leaves. Factors that can increase transpiration rate include highlight intensity, high temperature, low, humidity, and wind.
Identify to lifestyle diseases that can be more likely if you have a poor diet
 Cardiovascular diseases ,type two diabetes
Why can bacteria make us ill during an infection? What is different when comparing this to viruses?
Because bacteria releases toxins and causes damage to host tissues, while viruses make us ill by invading host cells and replicating inside of them
bacteria, single celled organisms that can be treated with antibiotics,
viruses are acellular entities that are not affected by antibiotics
When testing effectiveness of an antibiotic, using a agar gel,what is the size of a clear zone tell us?
A larger clear zone indicates that the antibiotic is more effectve in inhibiting the growth of bacteria, as it means the bacteria less resistant to the antibiotic 
What is the difference between antiseptic’s, antibiotics and disinfectants?
Antiseptic are used on living tissue
Antibiotics are used to treat bacterial infections
Disinfectants are used to kill or inhibit the growth of microorganisms
Identify three ways, a grower can limit the spread of tobacco mosaic virus through their crops
Use disease-free seeds
Practice good hygiene
Control vector organisms
Write for key points about salmonella infections, including cause,symptoms and how to limit the diseases 
It is caused by the bacterium salmonella
Found in intestines of animals, poultry, and can be transmitted to humans through contaminated food, water, and contact with infected animals 
Symptoms: diary, abdominal cramps, fever, vomiting
6 to 72 hours after infection
Write for key points about malaria, including cause,symptoms and how to limit disease
Malaria is caused by parasites, transmitted to humans through the bites of infected female mosquitoes
Symptoms: fever, chills, headache, muscle, aches, and fatigue
Sleep under an insecticide, take antimalarial medication and controlling mosquito populations through insecticides spraying are crucial, early diagnosis 
What actions do white blood cells take when a foreign microbe is detected inside the body
Phagocytes are white blood cells. They are attracted to pathogens. They surround them in the blood, bind to them and engulf them. The phagocytes’ membrane surrounds the pathogen and the enzymes.
Describe the changes in the number of antibiotics a person has before, during and after having a vaccine
In the second infection, the microbe is recognised, some existing antibodies, rapid immune response, mild/no symptoms, high antibodies production, antibodies made by memory cells
Give an example of an antibiotic in describe how they work. What kind of infections can they treat?
penicillin and amoxicillin. These can be taken to cure the diseases. by killing the pathogens close pathogenMicroorganism that causes disease., but only cure bacterial diseases and not viral ones.
Describe a typical stages of a drugs trial from start to finish
Stage one: preclinical testing
Single human cells – larger human tissues – whole animals
Drugs fail because: not affected, not safe,reach the target cells, dangerous side effects
Stage two: clinical trials on healthy volunteers
Giving low doses to healthy people – confirming if it reaches target cells – observing any dangerous side effects
Drugs fail because: dangerous side effects on healthy person, not safe on unhealthy volunteers, doesn’t work in human body reached the cells they need
Stage three: clinical trials on patients needing treatment
Only a small number of people tested first, testing on a range of doses to find the most effective, testing, much larger groups of people if it seems to be safe/successful
Drugs fail because:
The drug does not work, dangerous side effects
Identify three risk factors for lifestyle diseases, such as heart disease, stroke and COPD
Smoking ,unhealthy diet ,physical inactivity
What is the difference between benign and malignant tumours?
Benign:A tumour contained inside a membrane, which is more likely to spread
malignant: a tumour which is likely to spread and cause secondary cancer is throughout the body 
Why are smokers more likely to suffer from Conary heart disease?
Over time, fatty deposits ( plaque ) can build up inside the coronary arteries . This can reduce the flow of blood to the heart and increases the risk of heart attack. Smoking speeds up the clogging and narrowing of coronary arteries.
What is the relationship between BMI and risk of type two diabetes? Which gender are most at risk
The more excess weight you have, the more resistant your muscle and tissue cells become to your own insulin hormone.
Women
Identify four different carcinogens and the likely sources of exposure
Chemical carcinogens, like asbestos, tobacco smoke, beverages containing alcohol, aflatoxin (a fungus that contaminates food) and arsenic that appears naturally in the air, water and soil
What is the balance symbol and word equation for photosynthesis?
carbon dioxide + water —> glucose + oxygen + water.
6CO2 + 6H2O —> C6H12O6 + 6O2
State three factors that limit the rate of photosynthesis, what pattern can be seen in changing levels of each 
Temperature, carbon dioxide concentration and light intensity
What is the structure of starch? Where is it stored? Why is it valuable? When will levels rise/fall?

What is the balanced symbol on word equation for respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O (glucose + oxygen -> carbon dioxide + water).
Identify four, ways that organisms use energy released from respiration
Growth and repair of cells. Building larger molecules from smaller ones i.e. proteins from amino acids. Allowing chemical reactions to take place. Absorbing molecules in active transport.
Oxygen debt: what is it? When does it occur? How’s it over come?
The amount of oxygen required to remove the lactic acid, and replace the body’s reserves of oxygen, is called the oxygen debt. When someone who has been exercising pays back an oxygen debt, it can take from a few hours for normal exercise, to several days after a marathon
