genetics Flashcards
what is a nucleotide
-they form DNA
-nucleotides are the monomers, DNA is the polymer
what is a strand
many nucleotides joined together
what are the 3 parts of a nucleotide
phosphate, deoxyribose sugar, base (the base is the part that varies)
how to extract DNA from peas
-mix salt water and washing up liquid in a beaker
-mash peas to separate cells
-add to beaker
-transfer into boiling tube and put into hot water bath
-strain mixture
-place filtered juice into a boiling tube
-add enzyme solution to break down proteins holding DNA
-add ethanol slowly (50/50 ethanol to juice)
-White layer of DNA forms between juice and ethanol
allele
different forms of the same gene
phenotype
an organisms outward characteristics
genotype
the genes/alleles of an organism
heterozygous
having 2 different alleles for a particular characteristic
homozygous
having the same allele for a particular characteristic
dominant allele
an allele which has an effect in both heterozygous and homozygous
pure breeding
an organism is homozygous so only one type of allele can be passed onto offspring
punnet square
diagram showing possible genotypes and phenotypes which could form for offspring
what are gametes
sex cells
define meiosis
-cell division producing four non-identical, haploid gametes
-cells divide twice producing 4 unique daughter cells
What genotype produces a male baby
XY
What genotype produces a female baby
XX
what causes mutations
the wrong base may be inserted into the new DNA molecule
cloning an explant with tissue culture
-clean surfaces with ethanol
-cut a small explant off of a cauliflower
-sterilise explants in sodium and swirl every few minutes
-strain explants out from liquid
-place into agar plant growth medium stalk end first
-incubate in warm place with light
-explant should grow leaves and get larger
