Paper1 Biology

• mitosis process

  genetic material duplicated and sub cell stuff doubled

  nucleus breaks down

  chromosome pair pulled to each side with fibres

  cell divides and the nucleus divides
• what is the food test for starch?

  Iodine, turns from orange to dark brown or black
• what is the food test for protein

  biuret agent , blue to purple
• what is test for lipids/fats

  Ethanol will turn cloudy

  Sudan 3 dye has a red layer if fats are present
• What food does iodine test , what colour does it change to ?

  Starch ,from orange to brown black
• What food does Benedicts test? What colour

  Test for reducing sugars , colour blue to orange
• What food does buirets agent test for ?

  Tests for protein turns blue to purple
• What food does potassium hydroxide followed with copper sulfate test ?

  Protein (unsure wether it turns blue to purple)
• What does sudan 3 test for in food ?

  Lipids /fat, does not need to filter food as the layer of red will form on top
• Lung parts

  Trachea- bronchi-broncheoles-alveoli
• Factors of alveoli for gas exchange

  Large surface area (lumpy), good blood supply, oxygen binds to haemoglobin and goes to whatever. CO2 is in plasma and diffuses out here aswell
• How does blood travel around heart ?

  • Blood enters via vena cava
  • Into right atrium (view left side)
  • Into right ventricle with valves
  • Out to lungs via pulmonary artery
  • Back in via pulmonary vein
  • Into left atrium
  • Into left ventricle
  • Out to body via aorta
• Why is left side of heart wall thicker with muscle

  To pump blood around the body
• What are pacemaker cells

  Cells near right atrium that give out electrical pulses to contract the heart,

  can be replaced with a man made pacemaker if not working)
• Artery's have a

  Small lumen

  Thick wall

  High pressure

  Take blood to away from heart
• Veins have/are

  Big lumen

  Thin wall

  Valves to stop back flow

  Take blood to heart
• Capillary are/have

  1 cell thick walls

  Easy diffusion

  Very small

  Basically veins without valves but tiny
• Fat can buildup at the artery supplying bloody to the heart this causes

  Coronary heart disease
• Stents are

  Small mesh wires inserted into artery's to keep them open
• Statins are

  Prescribed drug that prevents buildup of fat in cardio vascular disease
• Other things caused by CHD or fatty buildup

  Strokes, peripheral artery diesease
• What is a non communicable disease

  A disease that cannot be spread , eg CHD, diabetes type 2 ,liver disease , cancer & carcinogens.
• What is a communicable disease

  A disease cause by a pathogen

  Eg, viral bacterial or fungal infection
• Begin tumors is a tumor that divides uncontrollably, they don't spread through body
• Malignant tumors are tumors that can spread through the body , difficult to treat.
• Xylem is

  Tube that carries water &minerals upwards
• Transpiration is effected by

  Increased air movement ,

  Increased temperature

  Decreased humidity
• The flower is a

  Reproductive orange on a plant
• Phloem is

  Tubes of cells that carry sugars and nutrients. Translocation is bidirectional
• What happens when a plant lacks nitrate ions

  Needed for protein synthesis deficiency causes

  Stunted growth

  Chlorosis (yellow leaves)

  Magnesium deficiency (no chlorophyll)
• Leaf structure

  • Waxy cuticle &upper epidermis
  • Palisade mesophyll
  • Spongey mesophyll
  • (Vascular bundle xylem ECT)
  • Lower epidermis with stoma and guard cells
• How do viruses 'reproduce'

  Viruses insert their DNA into human cells

  Causes the cell to produce more copies

  Cell exploads and virus infects more cells
• Example of communicate viruses

  • Measles (droplets)
  • HIV( causes AIDS)
• Bacterial release toxins in cells that damage them eg salmonella
• Fungi infect cells by protists , infect and destroy blood cells. Mosquitos ....
• Skin is the first barrier to pathogens

  Nose and trachea hair block pathogens

  Acid kill pathogens
• Lymphocytes are

  White blood cells that produces anti toxins and antibodies with attached to the antigen of cells clumping them together.
• Phagocyte are

  White blood cells that ingests the pathogens clumped together
• What are lymphocyte B

  A memory cell in white blood cells that copy the antibody and antigen to stop the pathogen next time . You are immune.
• Antibiotics kill bacteria but not always work , why

  Bacteria can become immune