Gen Intro Flashcards
(22 cards)
Factors that control traits are called
genes
Scientists call an organism that has two different alleles for a trait a
hybrid
What does the notation TT mean to geneticists?
two dominant alleles
What does the notation Tt mean to geneticists?
one dominant allele and one recessive allelle
What is probability?
the likelihood that a particular event will occur
What does a Punnett square show?
all the possible outcomes of a genetic cross
If a homozygous black guinea pig (BB) is crossed with a homozygous white guinea pig (bb), what is the probability that an offspring will have black fur?
100 percent
An organism’s physical appearance is its
phenotype
What does codominance mean in genetics?
The alleles are neither dominant nor recessive.
What happens during meiosis?
Chromosome pairs separate to form new sex cells.
When sex cells combine to produce offspring, each sex cell will contribute
half the normal number of chromosomes
What is a mutation?
any change in a gene or chromosome
Which term refers to physical characteristics that are studied in genetics?
traits
The different forms of a gene are called
alleles
Where does protein synthesis take place?
on the ribosomes in the cytoplasm of the cell
What does the notation tt mean to geneticists?
two recessive alleles
An organism’s genotype is its
genetic makeup
Which nitrogen base in RNA is NOT part of DNA?
uracil
An organism that has two identical alleles for a trait is
homozygous
A heterozygous organism has
two different alleles for a trait.
Which of these traits is controlled by a gene with multiple alleles?
blood type
Which combination of sex chromosomes results in a male human being?
XY
