B3 genetics Flashcards
(16 cards)
what is the difference between sexual and asexual reproduction?
sexual reproduction needs two parents and creates variation
asexual has one parent but one disease could kill whole population, no variation
explain meiosis.
Meiosis is a type of cell division that produces gametes (sperm and egg cells) for sexual reproduction, resulting in four genetically unique daughter cells
what are the 4 organic bases?
adenine (A), thymine (T), guanine (G), and cytosine (C)
why add ethanol to the solution, when extracting DNA from fruit?
ethanol allows the DNA to precipitate out of the solution.
describe the process of protein synthesis
- RNA polymerase binds to non coding DNA
- the two strands pull apart and the RNA allows the mRNA nucleotides to match their strand
- mRNA then moves to the ribosomes and are read in threes which correspond to the amino acids.
- amino acids are brought to the ribosomes in threes by the tRNA, the amino acids then connect together to form a polypeptide.
describe genetic varients:
a change in base occurs:
if in the coding region: the type of amino acid changes
if in non coding region: the RNA polymerase cant bind to the full DNA strand which effects the mRNA which also effects the final protein.
what is a gamete?
an organisms reproductive cell with 23 chromosomes (haploid)
what is an allele?
different forms of the gene, humans have two per gene
what is a gene?
a short section of DNA that codes for a protein
what is a chromosome?
a structure found in the nucleus made up of a long strand of DNA
what are the three parts of the nucleotide?
sugar, base, phosphate
what is the difference between homozygous and heterozygous?
homozygous contains two of the same allele e.g.aa AA
onthe other hand heterozygous has one dominant and one recessive
what does phenotype refer to?
refers to an observable trait.
what are the two diagrams involved with exploration of alleles>
Punnet square
family pedigree
what is the difference between genetic and environmental variation?
genetic - from mutations and sexual reproduction, random mutations occur.
environmental - a change to organism due the the organisms environment. e.g. a child with bad nutrition won’t grow
what does the human genome project help with?
find which genes caused inherited disorders, develop targeted therapies, and personalize treatments based on individual genetic makeup
