The different forms of a gene are called ____________
alleles
100
A heterozygous organism has __________________ for a trait.
two different alleles
100
What happens during meiosis?
Chromosomes separate and are distributed into new sex cells.
100
During DNA replication, adenine (A) always pairs with ________
Thymine (T)
100
What is a mutation?
any change in a gene or chromosome
200
Which term refers to physical characteristics that are studied in genetics?
traits
200
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%
200
Chromosomes are made up _______________
many genes joined together.
200
A mutation is harmful to an organism if it ______________
reduces the organism's chances for survival and reproduction.
200
The chromosomes in a pair may each have different __________ for each gene.
alleles
300
If D represents the dominant allele of a gene, then _______ represents the recessive allele.
d
300
An organism's genotype is its ______________
genetic makeup
300
When sex cells combine to produce offspring, each sex cell will contribute __________________ the number of chromosomes in body cells.
one half
300
What determines the genetic code?
the order of nitrogen bases along a gene
300
The process in which a parent cell divides twice to produce sex cells is called ______________
meiosis
400
Alleles that are neither dominant nor recessive produce an inheritance pattern known as ______________.
codominance
400
What does a Punnett square show?
All the possible outcomes of a genetic cross.
400
What is the chromosome theory of inheritance?
Genes are carried from parents to offspring on chromosomes.
400
What is copied during replication?
the cell's DNA
400
Mitosis is the stage of the cell cycle during which ____________.
the cell's nucleus divides into two new nuclei.
500
A chart used to predict results of genetic crosses is known as a ________________
Punnett Square
500
An organism that has two identical alleles for a trait is ____________.
homozygous
500
If a ___________ allele is present, its trait will appear in the organism.
dominant
500
What does messenger RNA do during protein synthesis?
copies the coded message from the DNA and carries it into the cytoplasm