B6 Inheritance v1 Flashcards
what is DNA
it is the chemical that contains all the genetic information of the cell
describe the make up of your DNA
It is a polymer which is made up of two strands coiled together to make a double helix
what is a gene
a small section of DNA found on a chromosome. It codes for a specific protein
how many different amino acids can a gene code for
20
what do genes specifically tell cells
what order to put the amino acids, which potentially make up 1000’s of different combinations
define a genome
the collective term for the entire set of genetic material in an organism
2 reasons why understanding the human genome is helpfull
Helps scientists to track inherited disease and trace the migration of people
What is the monomer for DNA
nucleotides
what three things do a nucelotide contain
one sugar molecule, one phosphate molecule and one ‘base’
what are the two possible pairings of bases according to ‘complementary base pairing’
A and T. C and G
what does the mRNA do
it acts as a messenger between the DNA and the ribosome, carrying the code to make proteins
three functions of proteins
enzymes(act as biological catalysts). Hormones (used to carry messages around the body). structural proteins
what is a mutation
a random change to an organisms DNA code
what specifically does a mutation do
It changes the sequence of DNA bases in a gene
why might the function of a protein be affected by a gene mutation
because the bases of DNA codes the sequence of amino acids which make up a protein
what does an insertion mutation do
it changes the the groups of three bases are read
what are the three types of genetic mutation
insertion, deleteions, substitutions
what do the mother and father create during sexual reproduction
gametes
how many chromosomes does. gamete contain
23
what type of cell division occurs in sexual reproduction
meiosis
what type of cell division occurs in asexual reproduction
mitosis
describe the first three steps of meiosis
“1- before the cell divides it duplicates its genetic information, forming two armed chromosomes. 2- for the first
division the pairs then line up in the centre of the cell. 3- the pairs are then pulled apart therefore forming two
cells with the same genetic information”
describe the final three steps of meiosis
“1- for the second division, chromosmes line up again but this time the arms are pulled apart. 2- you then end up
with four gametes with different genetic information as the chromosomes have been shuffled up during meiosis”
two advantages sexual reproduction has over asexual reproduction
“1- Mixture of chromosomes from both parents causes variation. this causes increased survival rates.
2- better survival rates means breeding spread survival characteristics through variation”
two advantages asexual reproduction has over sexual reproduction
only needs one parent, less energy needed to find a mate, can happen faster
what is the combination of chromosomes that makes you a male
XY
what is the combination of chromosomes that makes you a female
XX
what is an allele
the part of a gene from 1 chromosome,
how many copies of each chromosome does a gene have
2
what is your genotype
the combination of alleles you have
what is your phenotype
the set of characteristics you have as a result of your combination of alleles
what does it mean if two alleles match
it means they have the trait
if an allele for a disorder is recessive, what does that mean for people with only of the allele
it means they do not have it but could carry it as when breeding , it could match with another allele of the same kind
what is a dominant allele
a gene that produces its effect in the presence of the other (recessive) allele
