Gregor Mendals Principles of genetics (DONE) week10

EXAM #3

Why did Gregor Mendel replicate each mono hybrid crossing experiment many times?

Increasing the probability of detecting significant patterns in the results

Which “Principles of Inheritances” emerged from Gregor Mendel’s impressive series of mono hybrid crossing experiments?

Principle of segregation and Principles of dominance

Describe the purpose of the testcorss

determines the genotypes of individuals with a dominant phenotype

Which result from a testcross shows the individual has the heterozygous genotype?

Pp

Which result from a testcross shows the individual has the homozygous dominant genotype?

PP

Which result from a testcross shows the individual has the homozygous recessive genotype?

pp

In the nucleus of diploid (2N) cells, why are there two alleles for each gene on the autosomes?

one allele of a gene from each parent

Do human males have two copies of each gene on the X chromosome?

No, human males do not have two copies of each gene on the X chromosome

Do human males have two copies of each gene on the Y chromosome?

No, human males do not have two copies of each gene on the Y chromosome

Which type of cell division enables the production of haploid (1N) gametes from diploid (2N) germ-line cells?

meiosis

According to Gregor Mendel’s law of segregation, Do one allele or both alleles of a gene enter each gamate during meiotic cell division?

Only one allele

Why don’t different flower color traits of each parent mix in their offspring?

Mendel’s law of segregation

Propose a molecular biology hypothesis to account for why only one of the two different allels of a gene is expressed in the phenotype of some heterozygotes.

only one allele is expressed in the phenotype of some heterozygotes because the dominant allele produces a functional gene produce and the recessive allele is non-functional

Is the achondroplasia phenotype recessive or dominant?

Dominant

How can wild-type parents have a child with achondroplasia?

spontaneous dominant mutation

No person is homozygous dominant (AA) for the allele that causes achondroplasia. Why?

It is lethal which is why all living individuals with the condition are heterozygous

How many recessive alleles must an individual inherit to express the recessive phenotype?

Two recessive alleles