Heredity
The notation TT means an organism has two ________ alleles.
What is dominant?
A Punnett square shows _________?
What is all of the possible outcomes (offspring) of a genetic cross?
If a woman has five sons, what is the probability that she will have a sixth son?
50%
A ____________________ organism is the offspring of many generations of organisms that have the same trait.
What is homozygous?
Light eyes, straight hair, blonde or red hair
Physical characteristics that are studied in genetics are called ______.
What are traits?
What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea plants?
What is 3/4 or 75%?
What is the probability that the offspring will be tall?
Father is TT and mother is tt.
100%
If a ___________________ allele is present, its trait will appear in the organism.
What is dominant?
What is an example of a dominant trait?
Brown hair, brown eyes, curly hair
Traits are passed down to offspring from the ___________________ generation.
parental
An organism's genetic makeup.
What is its genotype?
What is the probability that the offspring have brown eyes?
Father is BB and mother is bb.
100%
Gregor Mendel was the first scientist to recognize that the principles of _______________ can be used to predict the results of genetic crosses.
What is probability?
T = tall
t = short
What is the phenotype of a person with Tt?
Tall
Gregor Mendel used these plants to study traits.
Pea plants
What is the difference between a gene and an allele?
A gene is a factor that controls traits. An allele is different forms of a gene.
What is the probability that the offspring will have red hair?
Father is Rr hand mother is rr. (Remember that lowercase r is red. It is a recessive trait.)
50%
What are the two possible alleles for a homozygous gene?
TT or tt
b = blue eyes
B = brown eyes
If the phenotype is blue eyes, what is the genotype?
Explain the difference between genetics and heredity.
Heredity is the passing of physical characteristics from parent to offspring. Genetics is the scientific study of heredity and how it works.
What are the three names for the generations that Mendel named in his study of pea plants?
Parental, First Filial, and Second Filial
What is the probability that the offspring will be short?
Father is TT and mother is Tt.
0%
A woman gives birth to a son. Two years later, she gives birth to another son. What is the probability that her third child will be a girl? Explain your reasoning.
The probability is 1 in 2, or 50 percent. The two possible results—having a boy or having a girl—are equally likely with each birth. Because each birth is an independent event, the probability that one result will occur does not depend on previous births.
_________ make up our DNA, and DNA makes up our chromosomes.
Genes