Question

19) What does it mean when a person is termed as a "carrier" for a certain trait (meaning it is an allele that's present but unexpressed)? Give an example using letters.

20) In Mendel's experiment, his F1 generation's flowers were all purple. This meant that this form of the flower color trait was what?

21) What's the relationship between 3:1 ratio and makeup of parents (homozygous/heterozygous)?

22) F2 Generation of Mendel's dihybrid plants showed what genotypic ratio and what phenotypic ratio? What was the genotype of the parens of F2 generation?

23) Allelic makeup of an individual is called its _____ and expression/manifestation of that "blueprint" is called its ____?

Answer 1

19. carrier for a certain trait means that it is an allele that's present but unexpressed. Ex. a trait that is X-linked recessive. Suppose the allele of a gene R is dominant, r is recessive and is X-linked, it can be written as X^R X^R , X^r X^R (carrier), X^rX^r. The disease-causing allele is in the last two genotypes but not expresses in the 2nd once because R is suppressing r. in the later generation, it can be transferred to the progeny and they might be affected, these are the carriers.

20. This means that the purple color flower trait is the dominant trait.

21. For a 3:1 ratio, the parents were heterozygous with one dominant and one recessive allele.

	P	p
P	PP	Pp
p	Pp	pp

22. Phenotypic ratio 9:3:3:1

Genotypic ratio 1:2:1:2:4:2:1:2:1

The genotype of parents - RrYy (for alleles R,r, y, Y).

23. The allelic makeup of an individual is called its Genotype and expression/manifestation of that "blueprint" is called its Phenotype.