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
