Topic 28-29: Genetics Flashcards
Describe Mendel’s monohybrid cross. What did he learn from this cross?
Mendels monohybrid cross presents that when two homozygous genotypes are crossed together it results in the opposite phenotype.
We end up with a heterozygous result.
Through this result mendel understood that the alleles of the same gene seperate in Meiosis or segregate.
Describe Mendel’s dihybrid cross. What did he learn from this cross?
In Mendels dihybrid cross presents that the alleles of different genes ar not attached to one another but assort independently.
Compare the law of segregation and the law of independent assortment. Describe the events of Meiosis that is responsible for each law.
The law of segregation states that alleles of the same gene segregate in Meiosis.
The law of Independent Assortment states that alleles of different genes are indepenndent from one another.
Metaphase in Meiosis is responsible for the Law of Independent Assortment.
Anaphase in Meiosis is responsible for the Law of Segregation
For an individual with the genotype AaBbCc, what are all the possible gametes this individual can make?
An individual with the genotype AaBbCc will have 8 possible gametes that this individual can make.
What are the “and” and “or: rules of probability? Provide some examples of when you would use each
The “and” rules of probability is the probability that two events will occur independently.
The”or” rules of probability is the probability that either of the two events will occur or more events.
What is a testcross? What are the expected results for a testcross with a homozygous dominant? A heterozygote?
A test cross is used to determine a genotype that displays a dominant phenotype.
A homozygous dominant results expected is 100% all will demonstrate heterozygous results.
A heterozygous dominant will result into 50/50% we will have 50 Bb and 50 bb
Distinguish between codominance and incomplete dominance. What are some examples of each?
Incomplete dominance is when the heterzygote of the two alleles is a mix of both the alleles or something in between.
Ex: Red flower crosses with White flower it will be a pink flower.
Codominance: The two alleles are expressed individually together.
Ex: allele I^A and allele I^B cross we get bloodtype B.
Explain the inheritance of blood types in humans. What are the possible genotypes and phenotypes?
Inheritance of Blood Types:
Blood Type
AB - I^A I^B
A- I^A, I^Ai
B - I^B, I^Bi
O- ii
How can pedigrees be used to determine pattern of inheritance? What trends would expect to see in an autosomal dominant trait? An autosomal recessive? X-linked recessive?
Pedigrees determine patterns of inheritance by looking at traits passed down from generation to generation.
Autosomal dominant trait will be present in every generation. Every individual with a trait will have the a parent with that same trait. These parents can have a child without the trait
Autosomal recessive trait will sometimes not be present in every generation. Parents without the trait cannot have a child with the trait.
X-linked recessive: Will be present in males, as recessive. Females will act as carriers for the recessive trait.
Explain how X-linked traits are inherited. Can a male pass his colorblind trait to his son? Why or Why not?
X-linked trait inheritance means the gene causing the trait or the disorder is located on the X-chromosome.
Yes, a male can pass his colorblind trait to his son because males only have one X chromosome, which means the trait comes from the X chromsomes and only that can be passed down to the son.
