Biology Flashcards
(36 cards)
A short pea plant would have to be
Homozygous recessive
Recessive traits occur only when an organism is
Homozygous
If a female guinea pig homozygous dominant for black fur color is mated with a male the is homozygous recessive for white fur color, in a litter of eight offspring you would expect
8 Black guinea pigs
A dogs phenotype can be determined by
Looking at it
A couple has two children, both of whom are boys. What is the chance that the parents next child will be a boy?
50%
Factors that control traits are called
Genes
What does the notation TT mean to geneticists?
2 dominant alleles
What does the notation Tt mean to geneticists?
1 dominant allele and 1 recessive allele
An organisms physical appearance is its
Phenotype
What does the notation tt mean to geneticists?
2 recessive alleles
An organisms genotype is its
Genetic makeup
An organism that has two identical alleles for each trait is
Homozygous
A pet stores customers prefer pet mice with black fur over mice with white fur. With this in mind, the owner crossed a female with black fur and a male with black fur. When the mice were born, she was surprised that three of the ten offspring had white fur. She did not know that the page were heterozygous for fur color. Which letters represent the genotypes of the parents in the above paragraph?
Bb
A pet stores owner raises mice, both black and white. Black fur is dominant to white fur. How could the pet store owner breed a litter of only white mice?
By making sure that both the mother and father have white fur
If a pet store owner were to cross one homozygous Black mouse with a heterozygous black mouse, what percent of the mice would you expect to have white fur? Work Punnett square on scratch paper
0%
Red eyes (R) are dominant in fruit flies, while brown eyes (r) are recessive. If a fruit fly has a homozygous dominant genotype, what color eyes will it have?
Red
An organism carries both the dominant and recessive form of a trait. How will the trait be expressed by the organism?
Only the dominant trait will be expressed throughout the organisms life
In peas, the color yellow (Y) is dominant to the color green (y). Show a Punnett square crossing two heterozygous plants. What percentage of the offspring of two heterozygous yellow pea plants. What percentage of the offspring of the two heterozygous yellow pea plants will most likely be homozygous green plants? Work on scratch paper.
25%
The man who studied inheritance in peas and known as the “Father of Genetics” is
Gregor Mendel
A segment of DNA on a chromosome is called a
Gene
A cross used to determine the genotype of an individual with a dominant phenotype is
A test cross
Assume that brown eyes (B) are dominant over tan eyes (b) in guinea pigs. When a brown-eyed make is mated with a tan-eyed female, 50% of the litter has brown eyes and 50% has tan eyes. What is the genotype of the female guinea pig?
bb
A dominant gene that codes for white hair is represented by the symbol W. If a parent with the genotype WW is crossed with a parent of genotype Ww, what percent of their offspring will have white hair? Work your punnett square on scratch paper.
100%
Assume that in humans there is a 50/50 chance that a child will be a boy. If a certain mother and father have four sons, what are the chances that their fifth child will be a daughter?
50%
