bio genetics
This black dog has the genotype of BB for fur color. The black dog mates and has puppies with a solid white dog. The white dog has the genotype bb. What is the probability that this match will produce puppies that are also white?
0% of the offspring will be white.
How many of the bunnies would you expect to be brown and how many would be white?
165 Brown and 55 white
What is the ratio of genotypes when you cross a homozygous recessive trait with a heterozygous trait?
1:1
In a cross between two heterozygous individuals (eg. Rr X Rr), the expected genotypic ratio of the offspring would be:
1:2:1 1-BB; 2-Bb; 1-bb
Heterozygous means ______ alleles that are _______
2, different
Homozygous = ______ alleles that are the _______.
2, same
Consider the possible genotypes of the offspring of two heterozygous brown goats. The ratio of brown to white offspring in this case would be
3:1
In a cross between two heterozygous individuals (eg. Rr X Rr), the expected phenotypic ratio of the offspring would be
3:1
Several biology students are counting kernels in an ear of corn. They count a total of 550 kernels: 316 purple wrinkled, 104 purple smooth, 90 yellow wrinkled, and 49 yellow smooth. What is the best ratio of kernel phenotype in this case?
3:2:2:1
According to Mendel's law of dominance, when we cross a heterozygous red flower with a homozygous recessive white flower, we would expect ______ percent of the offspring to have white flowers.
50
Suppose a mother carries two recessive genes for freckles (rr) and a father carries one recessive gene for freckles and one dominant gene for clear facial skin (Rr). What is the likelihood that their first child will have freckles?
50%
R=round seeds/r=wrinkled seeds. You cross a parent that is heterozygous and a parent that has wrinkled seeds. Predict are the percentages of the genotypes?
50% Rr and 50% rr
Predict the percentages of phenotypes
50% round and 50% wrinkled
Consider the genetic cross for sex in humans. XX is female and XY is male. A family has 3 children, all girls. What are the chances that the family will have a boy as their fourth child? Explain your reasoning.
50%, offspring can only be male or female.
Brown rabbits have the genotype BB or Bb. White rabbits have the genotype bb. If two brown rabbits, both Bb, have baby rabbits, what is the probability that the baby rabbits will also be brown?
75
Predict the percentages of phenotypes
75% black, 25% not black
A population of rabbits follows the typical pattern of inheritance and the law of dominance for fur color. B is the allele for brown fur and b is the allele for white fur. Parent 1 is heterozygous brown while Parent 2 is homozygous recessive. In a population of rabbits, 160 bunnies are born. How many of the bunnies would you expect to be brown and how many would be white?
80 would be brown and 80 would be white
B=black fur. You cross two parents with heterozygous fur color traits. Predict are the percentages of the genotypes?
? 25% BB, 50%Bb, 25%bb
What is Mendel's Law of Dominance?
A dominant trait will always be seen over a recessive trait.
Describe the term 'purebred'
An organism whose ancestors are genetically the same
A cross between 2 parents resulted in a phenotype percentage for being brown of 100% brown. What is the genotype of at least ONE parent Use the variable B.
BB
A black dog has the phenotype of black fur color. The black dog mates with another black dog and has 10 puppies. Of the puppies, there are two that are solid white, the rest are black. What are the genotypes of each parent
Bb for both parents
A cross between 2 parents resulted in a genotype for color ratio of 1:2:1. What are the genotypes of the parents? Use the variable C.
Cc and Cc
A population of mice follows the typical pattern of inheritance and the law of dominance for fur color. G is the allele for gray fur and g is the allele for white fur. Parent 1 is heterozygous brown while Parent 2 is gray whose mother was white. In a population of rabbits, 220 bunnies are born. What are the different genotypes?
GG, Gg, gg
Describe the difference between genotype and phenotype.
Genotype is the genetics or alleles for a trait, phenotype is the physical appearance that's expressed from the genetics.
A cross between 2 parents resulted in a genotype ratio for height of 1:1. What are the genotypes of the parents? Use the variable H
Hh and hh
Which of Mendel's laws BEST explains the reason an organism with 'Tt' will show only the dominant phenotype?
Law of Dominance
Which Mendelian law of inheritance states that organisms inherit two copies of each gene and donate one copy to each of their offspring?
Law of Segregation
According to the Punnett square: B represents the dominant gene for blue feathers and b represents the recessive gene for red feathers. Two heterozygous birds have one offspring. What percent chance does it have for red feathers?
One out of 4 or 25%
Describe Mendel's Law of Segregation.
That when chromosomes during meiosis, each egg or sperm will receive only one chromosome from each original pair.
Describe Mendel's Law of Independent Assortment.
The assortment of chromosomes for one trait do not depend on the assortment of chromosomes for a different trait.
In humans, curly hair is dominant over straight hair. Which cross below has the correct percentages listed? Select all that apply.
a woman heterozygous for hair curl, a man heterozygous for hair curl will produce 25% straight hair, 75% curly hair a woman heterozygous for hair curl, a man homozygous recessive for hair curl will produce: 50% straight hair, 50% curly hair 100% straight hair & 0% curly hair
Among a species of butterflies, the color blue (B) is a dominant trait. Yellow color (b) is a recessive trait. If a pure blue butterfly (BB) mates with a pure yellow (bb), what will the offspring look like?
blue
The form of a gene that is always expressed if present is the
dominant trait
Tt
hetero
If an organism inherits one dominant allele and one recessive allele for eye color, their genotype would be:
heterozygous
TT
homo
tt
homo
A population of red squirrelfish breeds and produces offspring, 75% are still red but 25% are yellow. This variation in the color of the squirrelfish can be explained by
the presence of a recessive allele for yellow color that was masked by a dominant red color allele.
