When an f1 plant undergoes meiosis, what gamete types will it produce, and in what proportions?
- A: 3/4 Y, 1/4 y
- B: 1/2 Y, 1/2 y
- C: 1/2 YY, 1/2 yy
- D: 1/2 Yy, 1/2 Yy
- E: 1/4 Y, 3/4 Y
- F: 1/2 y, 1/2 y
The correct option is B.
When an F1 plant undergoes meiosis, the gametes will be 1/2 Y and 1/2 y.
F1 generation: Parents – YY yy
Offspring: – Yy
When a homozygous yellow line (YY) cross with a homozygous green line (yy), it will result in F1 plants that are heterozygous (Yy) for the same trait and yellow seeds will be produced. If F1 generation is crossed, possibility B would be correct.
As the trait in F1 generation is heterogeneous, therefore the produced gametes will contain either the dominant allele or the recessive allele. Out of two gametes, one will carry the dominant allele, and the other one will be recessive allele. It means that 50% of the gametes will be dominant, and the remaining 50% will have the recessive allele.
The F1 generation is the offspring resulting from a cross between an organism that is homozygous dominant for a particular trait and a body that is homozygous recessive for a specific character. Therefore, 100% of the F1 offspring of this cross is heterozygous for the particular trait. Since only a single allele is present in the gametes after meiosis, these heterozygous alleles will segregate appropriately.
Law of segregation:
Gregor Mendel in the 1860’s, discovered the principles related heredity which include One the law of segregation, which states that allele pairs separate during the formation of gamete. Linking to this law, Mendel discovered that when gametes are produced during meiosis, allele pairs leaves each cell with a single allele by separating from each other.
In a heterozygous state, i.e. when two alleles of a pair are different, which is the typical genotype of Mendel’s F1 generation, one type of the gamete will contain a dominant allele. In contrast, the other type will contain a recessive allele.
Heterozygotic organism undergoes meiosis to produce gametes with an equal frequency of the allele, i.e. half (1/2) of the gametes will possess the dominant allele while the other half will possess the recessive allele.