DNA, RNA, and genetics

• Phenylthiocarbanmide paper (PTC paper) is a good example of how genetic traits differ from person to person
• Each chromosome in a sexually produced child has 1 sister chromatid from each parent, to their genes can transfer or not transfer identical copies of their traits or charecteristics
• Gene locuses are specific areas in the chromosome that code for specific traits
• Allele from the parents is put together with an allele from the other parent to form the gene of the child
• To represent an allele, a capital or lowercase letter can be used. Capital letters show dominant alleles while lowercase letters show recessive alleles. Recessives are usually not expressed in the presence of a dominant.
• Your combination of alleles form your genotype, your genetic makeup which can influence your phenotype, your physical charecteristics
• Dominant traits can be expressed by two combinations (TT, Tt) while recessive traits can only be expressed by one combination (tt)
• A combination of your parent's genes will form your traits- changes in your traits can help you trace their genotypes

  
• For polydactyl (extra finger), the recessive allele is more common. This means that most people have two copies of the recessive allele and are therefore not polydactyl -> dominant disease

  
  

  For a dominant allele to be rare:

  1. Selection pressure: favored the recessive allele over the dominant allele.

  2. The dominant allele may have arisen from a recent mutation, making it less common.

  3. Random events, such as chance variations in population size, could have decreased the frequency of the dominant allele.
• Genome - all of the DNA in an organism
• The DNA you have upon fertilization is all the DNA you'll ever have in your life
• Nuclear DNA is spread across 23 paired chromosomes, Mitochondrial DNA is in the mitochondria and Chloroplast DNA is found in plants and algae
• Nuclear DNA includes sequences of nucleotides that are repetitive, regulatory (can be turned off/on), non-coding (introns), or genes
• Chromosomes are super-coiled DNA that are associated with structural proteins
• A gene is a sequence of DNA nucleotides that codes for RNA or a protein product
• Gene expression is the process of genes creating products

  
• Still a hot debate: How many protein making genes in a genome?

  ~21306 K
• Locus: The position of the DNA at which a gene is located

  
• Allele: variation of a gene
• Human genomes can be split into two main catagories

  
• Adenine always pairs with Uracil (RNA) or Thymine (DNA), while Cytosine always pairs with Guanine. This is pair specificity
• Forming a polypeptide from RNA - Translation
• Coding for RNA from DNA - Transcription
• Each band of a stained chromosome is the location of a different gene - False
• Alleles of a gene have the exact same nucleotide sequence - False
• Only recessive alleles cause disease - false
• There is a max of two alleles for each gene in the population - False
• There is a max of two alleles of each gene in an individual
• The genome Sars-CoV2 for the COVID virus is a linear, single stranded RNA
• As an infected cell builds new coronaviruses, it occasionally makes tiny copying errors called mutations.
• Scientists can track genetic changes as they are passed down through a lineage, which is a branch of the viral family tree.
• A group of coronaviruses that share the same inherited set of distinctive mutations is called a variant
• If enough mutations accumulate in a lineage, the viruses may evolve clear-cut differences in how they function. These lineages come to be known as variant
• The four structural proteins of the Sars-CoV2 include Spike (S), Nucleocapsid (N), Membrane (M), and Envelope(E) protein
• The Nucleocapsid is responsible for protecting the genome of the virus
• The spike facilitates entry of the virus into its target cell
• The envelope and membrane helps new virus particles assemble and then bud from the infected cell
• There are 29674 nucleotides in the Sars-CoV2 genome
• The Sars-CoV2 genome encodes 29 proteins
• The spike structural proteins is the largest in Sars-CoV2 virus