topic 3 - genetics Flashcards
what do we add to the mixture of extracting fruit to make the DNA soluble/ visible?
add ice cold ethanol to slow down enzymes naturally present in the cell and break down the DNA
how do you break apart the membrane surrounding the cell and nucleus and release the DNA?
add detergent
how do you uncoil DNA?
add protease enzyme
why is salt mashed with fruit when extracting its DNA?
because it breaks the cells apart from each other and starts to break down the cell walls
salt specifically used because it means that the DNA is more likely to clump together in the final stage
what is the role of meiotic cell division?
produces 4 daughter cells each with half the number of chromosomes. resulting in the formation of genetically different gametes
DNA is a polymer made up of what?
2 strands coiled to form a double helix
strands linked together by complementary base pairs joined together by weak hydrogen bonds
nucleotides that consist of a sugar and a phosphate group with 1 of 4 different bases attached to the sugar
what is the genome?
the entire set of DNA in an organism
what is a gene?
section of a DNA molecule that codes for a specific protein
what are some advantages of sexual reproduction?
creates genetic variation
if environmental changes happen, its likely some of the offspring will survive
leads to evolution and natural selection
what are some disadvantages of sexual reproduction?
requires time and energy
create fewer offspring in their lifetime
2 parents needed, can be a problem if individuals are isolated
what are some advantages of asexual reproduction?
dont need to find a mate
rapid reproductive cycle
can reproduce when conditions are favourable
can allow an organism to colonise rapidly
what are some disadvantages of asexual reproduction?
no variety in the population
if a disease breaks out they are all at risk and could wipe out the whole population
