Question
In Mendel's "Experiment 1, true-breeding pea plants with spherical seeds were crossed with true-breeding plants with dented seeds. (Spherical seeds are the dominant characteristic). Mendel collected the seeds from the grew F1-generation plants, let them self-pollinate to form a second generation and analyzed the seeds of the resulting F2 generation. The result that he obtained and that you would predict for the experiment are: A. 1/2 the F1 and 1/4 of the F2 generation you seeds were spherical B. 1/2 the F1 and 1/4 of the F2 generation seeds were dented. C. All of the F1 and F2 generation seeds were spherical D. 1/4 of the F1 and 9/16 of the F2 generation seeds were spherical. E. All the F1 and 1/4 of the F2 generation seeds were spherical. What was the importance of Mendel performing reciprocal crosses? A. To be able to breed plants all year round B. To obtain enough plants to perform the experiments that Mendel wanted, which would not have been sufficient without performing reciprocal crosses. C. To disprove a hypothesis at the time the experiments were performed that stated the ovum carried all the information for progeny. D. To demonstrate that the inheritance of a trait was not dependent on which parent carried the trait. The mutations found in the CF gene that result in cystic fibrosis are recessive because A. Normal or near normal cellular function can occur from the protein produced by the normal allele. B. The CF mutations that occur result in no protein being produced, C. CF mutations only result in a protein that has normal function if there is also a normal CF protein in the cell. D. CF is fatal and if the alleles that caused CF were dominant it would not be inherited Which type of chromosome provides the basis for sex determination in many sexually reproducing organisms? A. haploid B. diploid C. autosomes D. sex chromosomes E. homologous chromosomes The reason that the HD allele acts as a dominant allele is A. The mutant HD allele suppress protein production from the normal HD allele. B. The HD mutations results in a protein that can damage nerve cells even in the presence of the normal protein C. The does not normally produce protein but the mutant HD allele does. D. The protein produced from the mutant HD allele is non-functional.
Explanation / Answer
2. E) All of F1 and 3/4th of F2 were spherical
The F1 will be a dominant heterozygote and when two dominant heterozygotes are crossed, 25% is homozygous dominant, 50% is heterozygous dominant and 25% is homozygous recessive. Therefore 75% I.e. 3/4th is dominant spherical .
3. D) To demonstrate that the inheritance of a trait was not dependent on which parent carried the trait.
4. D) CF is fatal and if the alleles that caused CF were dominant it would not be inherited.
These would not be inherited if dominant because CF is fatal and if they were dominant then the individual carrying the trait would die, and thus, they wouldn't be inherited.
5. D) S-ex chromosomes
6. C) The normal HD allele does not normally produce a protein but the mutant HD allele does
The Huntington's disease is inherited from the parents as an autosomal dominant allele and the disease is caused by a new mutation with the gene called Huntingtin.
