Biology

• Components of blood:

  white blood cells, red blood cells, plasma, platelets
• What does Plasma transport?

  • red blod cells
  • white blood cells
  • platelets
  • digested food products form the gut to all the body cells
  • Carbon dioxide from body cells to lungs
  • Urea from liver to the kidneys
  • Hormones
  • Heat energy
• The vaccination can be one of these things:

  A dead pathogen

  A weakened strain of the actual pathogen

  Modified toxins of the bacteria

  The antigens removed from a pathogen
• A recessive allele is only expressed if the individual has two copies and does not have the dominant allele of that gene
• A dominant allele is always expressed, even if one copy is present
• Mouth:

  • Salivary glands in the mouth produce amylase enzyme in the saliva
  • Teeth break down food
• Oesophagus:

  • muscular tube that conncents mouth and stomach
• stomach:

  • Pummels the food with its muscular walls
  • propduces pepsin
  • Produced hydrochloric acid to kill bacteria and give the optimumum pH for the proteast enzyme to work.
• Liver: produces bile
• Gall bladder: stores bile
• pancreas: produces protease, amylase and lipase enzymes which are released into the small intestine
• Large intenstine/colon: excess water is absrobed from the food
• small intestine:

  • produced protease amylase and lipase enzymes to complete digestion
  • Where nutrients are absorbed out of the alimentary canal into the body
• rectum: faeces are stores before they leave through the anus
• Food moves along the gut by a process called peristalsis.

  The gut has two layers of muscle, one is circular and the other is

  longitudinal.

  They work together to push the food along like a squeezing wave.
• The palisade layer is packed with chloroplasts for photosynthesis.

  The leaf has a transparent upper epidermis to let light through to the

  palisade layer.

  The leaf has a broad shape to increase surface area to catch more light.

  The leaf is thin to allow rapid diffusion for gaseous exchange.

  The leaf has air spaces in the spongy layer to allow for gaseous

  exchange.

  The leaf has lots of stomata to allow for gaseous exchange.

  The leaf has guard cells to control if the stomata or open or closed.

  The waxy cuticle reduces water loss by evaporation.
• Inhale:

  • intercoastal muslces contract whcih amkes ribs move up and out
  • diaphragm contract and flattens
  • thorax increases in size and air pressure increases
  • air is forced in
• exhale:

  • intercoastal muslces relax which makes ribs move down and in
  • diaphragm relaxes back to its dome shape
  • thorax decreases in size and air pressure decreases
  • air is forced out
• Fungi do not carry out photosynthesis. Their body is usually organised into a mycelium made from thread-like structures called hypae . Fungal cell walls are made of chitin. Fungi feed by extracellular secretion of enzymes onto food material and absorption of the organic products. This is known as saprotrophic nutrition.
• polygenic - genetic control where many genes control one phenotype.
• Cloning an adult mammal:

  1. nucelus of a sheep's egg cell is removed creating an enucleated cell (egg without a nucleus)
  2. Diploid nucelus (full set of paired chromosomes) was inserted in its place. This is a nucelus from a mature udder cell of a different sheep.
  3. The cell was stimulated (by an electric shock) so that it starts dividing be mitosis like a normal fertlised cell.
  4. The dividing cell was implanted into the uterus of another sheep to develop until it is ready to give be born.
• Adrenaline is produced in the adrenal glands. They trigger a flight or fight resonds. THis increases heart rate, blood flow to muscles and blood sugar levels.
• insulin is produced by the pancreas, they help control the blood sugar level. This stimulates the liver to turn glucose into glycogen for storage.
• Progesterone is produced in the ovaries, they sipport pregnancy. They mantain the lining of the uterus.
• ADH is produced by the pituitary gland (in the brain),it controls water content. It increases the permeability of the kidney tubules to water.
• FSH is produced by the pituitary glands, they cause an egg to mature in an ovary. This is stimulated the ovaries to produce oestrogen.
• LH is produced in the pituitary gland. It stimulates the release of an egg from an ovary.
• Pulmonary means to do with the lungs

  Hepatic means to do with the Live

  renal means to do with the kidneys
• Osmoregulation is the control of blood concentration and mineral levels
• Non-overlapping bases:

  • Allow one codon determines each amino acid
  • bases are not shared between amino acid
• chlorophyll absorbs red, blue light and does not absorb green light
• transgenic: the transfer of genetic material from one species to a different species
• heat loss via the stages: not all organisms are eaten, energy is lost due to respiration, heat loss, some is not digested, some lost as faeces.
• micropropagation uses small fragments of plants which are regrown into whole plants. These fragments of plants are known as explants.

  the surface fo each fragment is sterilised to prevent growth of microorganisms. The fragments are placed in a growth medium which contains agar and a source of energy such as glucose. This method is able to produce large quantities of genetically idetical plants called clones.
• One advantage is that micropropagation is quicker than sexual reproduction, which involves flower and seed production. Another advantage of micropropagation is that plants can be produced anytime of the year.