JSIERT

(A) The F1 generation’s flower will be blue in colour.(b) If the F1 generation’s flowers self-pollinate, then 25% of the F2 generation’s flowers must be white.(c) A 1:2 ratio between the genotypes BB and Bb is expected in the progeny of the F2 generation.The cross shown above could represent the results mentioned above:

(a) The possible cross of Mendel’s experiment is: As a result, tallness (T) is dominant and dwarfness (t) is recessive. Only dominant traits show in the F1 generation; recessive traits are suppressed. Both dominant and recessive features, or F2 generation, express themselves. Mendel’s experiment demonstrated that the traits (tall and dwarf) are inherited independently in …

(a) Mendel crossed tall pea plants with dwarf pea plants in his experiment. Write his observations giving reasons for the F1 and F2 generations.
(b) List any two contrasting characters other than the height that Mendel used in his experiments in pea plants. (Delhi 2014) Read More »

(a) The cross in question was produced with two pea plants only used for breeding, one with round, green seeds and the other with wrinkled, yellow seeds.Green seed colour and wrinkled seed shape are dominant to yellow seed colour and spherical seed shape. Recessive features are stifled in the F1 generation, while dominant traits are …

A cross was made between pure breeding pea plants, one with round and green seeds and the other with wrinkled and yellow seeds.
(a) Write the phenotype of F1 progeny. Give reason for your answer.
(b) Write the different types of F2 progeny obtained along with their ratio when F1 progeny was selfed. (Delhi 2014, Delhi 2013C) Read More »

When male and female gametes fuse during fertilisation, sex is formed. Gametes with an X or Y chromosome are produced by males, whereas gametes with an X chromosome are produced by females. When male and female gametes combine to form a zygote during fertilisation, the sex of the baby is determined. The offspring will be …

“It is a matter of chance whether a couple will have a male or a female child.” Justify this statement by drawing a flow chart. (Foreign 2015) Read More »

A pure tall pea plant and a pure dwarf pea plant were crossed by Mendel. Every plant produced from the F1 generation was tall. Mendel obtained both tall and dwarf plants in the ratio of 3:1 in the F2 generation when he selfed plants from the F1 generation.As an example, consider the following: This explains …

Explain Mendel’s experiment with peas on inheritance of characters considering only one visible contrasting character. (Foreign 2016, 2014) Read More »

Differences between dominant traits and recessive trait are given below: Dominant trait Recessive trait (i) It is the trait controlled by the dominant allele. It is a recessive allele-controlled characteristic. (ii)It is the feature that the F1 generation expresses. It is the feature that does not emerge in the F1 generation but does in the …

List two differences in tabular form between dominant trait and recessive traits. What percentage/proportion of the plants in the F2 generation/progeny were round, in Mendel’s cross between round and wrinkled pea plants? (Foreign 2016) Read More »

The example provided can help to clarify how a trait might be inherited but not always expressed. The F1 generation of pea plants was all tall because a tall pea plant and a dwarf pea plant were crossed. Selfed F1 plants generated plants that were both tall and dwarf in the F2 generation. This demonstrates that …

With the help of an example justify the following statement: “A trait may be inherited, but may not be expressed.” (AI 2016) Read More »

The scientist can come to two different laws, namely the law of dominance and the law of segregation, under the situation described in the topic (or the law of purity of gametes). This can be explained with the help of the following crosses: In the F1 hybrid two dissimilar alleles are present for one character, i.e., …

In a monohybrid cross between tall pea plants (TT) and short pea plants (tt), a scientist obtained only tall pea plants (Tt) in the F1 generation. However, on selfing the F1 generation pea plants, he obtained both tall and short plants in the F2 generation. Based on the above observations with other angiosperms also, can the scientist arrive at a law? If yes, explain the law. If not, give a justification for your answer. (Delhi 2016) Read More »

  Mendel crossed the pea plant for two contrasting characters under consideration.  The feature that showed in the F1 generation was dominant, whereas the one that did not was recessive. Later, he selfed the F1 generation plants and recovered, resulting in the F2 generation having a clear proportion of both parental features. Mendel determined from …

How did Mendel interpret his result to show that traits may be dominant or recessive? Describe briefly. (Delhi 2016) Read More »