Terms in this set (28)
the sequence of DNA that codes for a protein and determines a trait
the different forms of a gene
both alleles for a trait are dominant, identical
an organism that has two different alleles for a trait- one recessive, one dominant
both alleles for a trait are recessive, identical
an organism's genetic makeup- g for gene
an organism's physical appearance, or visible traits- ph for physical
an organism with two different alleles for a trait, heterozygous, ex: Bb
an organism with two identical alleles for a trait, homozygous
ex: BB or bb
how many chromosomes do humans have? how many pairs of chromosomes?
46 chromosomes in total, 23 pairs
what are punnet squares used to show?
they show all the possible ways alleles can combine in a genetic cross, and the probability of certain traits
ex: if two parents both are heterozygous for brown hair, what is the probability their offspring will have brown hair?
ex: if the dad is homozygous recessive for blue eyes, and the mom is homozygous dominant for brown eyes, what would the probability be that the child has brown eyes? what would the probability be if the mom was heterozygous for brown eyes?
100%, 50% brown, 50% blue
both- co-dominance occurs when both alleles for a gene are expressed equally, and both phenotypes are visible
ex: the offspring of a black chicken and a white chicken is a speckled chicken with white and black dots, not a brown chicken
blend- incomplete dominance occurs when neither allele is fully dominant, so they both blend together
ex: the offspring of a white cow and a black cow is a brown cow, not a speckled cow
a trait inherited from relatives, related to heredity; something you are born knowing or having
ex: height, hair color
a trait that you acquire over time, not genetic; a trait that you learn or acquire
ex: speak a language, play the piano
who was gregor mendel?
the father of genetics and heredity; a priest who experimented with pea plants and introduced major changes; mendelian genetic
an abnormal condition that a person inherits through genes or chromosomes
ex: down syndrome, turner's syndrome
a person who has one recessive and one dominant allele for a trait, but does not have the trait, heterozygous, mostly for genetic disorder
what are four causes of cancer?
carcinogens, radiation, toxins, mutations
what does DNA stand for?
what is DNA shaped like?
double helix (twisted ladder)
what are chains of amino acids made up of?
they are composed of nitrogen bases, and they link to make proteins
what are the four nitrogen bases?
adenine, thymine, cytosine, guanine
what does mRNA stand for?
it stands for messenger RNA
when is thymine read as uracil?
in the RNA stage, thymine becomes uracil