biology*ੈ✩‧₊˚

• dna is a polymer made up of repeating units called monomers. these monomers are called nucleotides. each nucleotide contains 1 out of 4 bases that pair together. A and T. G and C.
• on the backbone of dna there is a sugar phosphate and a base making a nucleotide. hydrogen bonds hold the bases together. it produces proteins and is partly responsible for how you look
• cystic fibrosis is a recessive genetic disease that causes excess mucus production. this disease is fatal. life expectancy is around 40.
• huntingtions is a dominant genetic disease. the main symptom is a tremor. this disease is fatal, life expectancy is 55-60.
• to genetically test a fetus , there is amniocentesis. this is where a doctor removes amniotic fluid as it contains fetal skin cells. the cells contain genes that can be observed. there is some risks, for example 2 percent miscarriage rate , infection , not accurate.
• chorionic villus testing =uses flexible tongs to retrieve fetal cells from placenta.
• pgd= process used to genetically test an embryo.
• monomers are called nucleotides.
• the two types of bases are (adenine & thymine) and (cytosine & guanine).
• proteinsynthesis = process of how protein is made in the body
• first step of proteinsynthesis is: transcription occurs in the nucleus

  1. dna unwinds + unzips
  2. copy is made
• second step of proteinsynthesis: translation, which occurs on a ribosome. purpose= for each triplet to be read by ribosome

  1. ribsome reads base code
  2. joins the amino acids
• what is purpose of transcription?


  to make MRNA
• what is mrna?


  small strand of genetic information
• what is a structural protein?

  helps build and support
• what is hormone? chemical messenger released by endocrine glands to control bodily functions
• what are enzymes? catalysts that speed up chemical reactions
• an example of functional proteins?

  enzymes= take part in chemical reactions
• when does cvt testing happen?

  this only happens when the fetus is a couple weeks old. there is 1 percent miscarriage rate, infection and not completely accurate.
• what are the advantages of pgd?

  doesnt need you to consider abortion. + no infection related risks
• what are advantages of pgd?

  no infection related risks
• how can an embryo be genetically tested?


  using pgd
• what is pgd?


  two step process=

  1. ivf, where sperm and eggs are collected from parents from parents + under a microscope, egg and sperm cells are fused together. egg is watched until embryo is developed.
  2. pgd=embryos are scanned for birth defects, those affected are disposed whilst those unaffected are implanted into mum.
• how can we make insulin?


  using bacteria
• how can we make insulin using bacteria?

  1. identify + isolate plasmid
  2. cut insulin producing gene using enzymes
  3. put gene into vector
  4. insert new gene using enzymes
  5. new modified bacteria can be cultured + allowed to reproduce
• what are the concerns regarding insulin made by humans?

  1. dont know long term effects
  2. concerns about playing god
  3. unnatural process
• what is a pathogen?

  A pathogen is a microbe that causes disease.
• what are the factors of diabetes type 1?

  1. dont produce insulin
  2. onset occurs as a child
  3. caused by autoimmune disease
• what are factors of diabetes type 2?

  1. insulin resistant
  2. affects middle age people
  3. caused by lifestyle choices
• how is cancer caused?

  1. cells dna accumulates damage- mutation
  2. occurs due to lifestyle factors
  3. damaged cell fails to self destruct
  4. rapidly divides via mitosis forming tumor
• how many types of white blood cell are there?

  3
• what is wbc 1?

  first responder= produces antibodies that bind to pathogen's antigens

  causes pathogens to clump together [immobilised]
• how many days does it take to make antibodies?

  up to 10
• what is wbc 2?

  engulfs + digests the pathogen
• what is wbc 3?

  memory cell= remembers the shape of pathogens antigens
• why is wbc 3 important?


  if you ever come across same pathogen, body knows what antibodies to release
• why do we get multiple colds a year?

  1. viruses=high mutation rate
  2. at any time can change its dna
• how does a vaccination work?

  a inactive version of pathogen is inserted (small quantity) provokes an immune response.
• what are the risks of vaccines?
• what are the risks of vaccines?

  • side effects
  • headaches
  • sore arms
  • allergic reaction