Linkage and Crossing Over

When a group of genes shows linkage then they do not show independent assortment or recombination?

Fill in the blank with the correct option given in the bracket.

Due to incomplete linkage in maize, the ratio of parental and recombinants are _____.(7:1:1:7/1:2:7:1)

Which of the following sentences are correct?

In Drosophila, the genes for the body color and eye color are present on:

The split-gene arrangement further complicates the definition of a gene in terms of a _____.

The two _____ of a gene pair are located on homologous sites on homologous chromosomes.

What is synapsis?

Write a note on crossing over.

Cotyledons are also called-

When white eyed and miniature winged Drosophila melanogaster is crossed with its wild-type, it produces following per cent of recombinants.

Linkage groups can be separated during __________ in meiosis.

A pure breeding pea plant with the dominant phenotype of character A and recessive phenotype of character B was crossed with another pure breeding plant with the recessive phenotype of A and dominant phenotype of character B. A offspring of this cross was crossed with a homozygous recessive for both the characters - A and B. The following results are obtained 22 were phenotypically dominant for A and recessive for B.

4 were phenotypically dominant for both A and B.

4 were phenotypically recessive for both A and B.

24 were phenotypically recessive for A and dominant for B.

These results show that

Mendel did not recognize the linkage phenomenon in his experiments because

Distance between the genes and percentage of recombination shows:

Two linked genes a and b show 40% recombination. The individuals of a dihybrid cross between ++/++ X ab/ab shall produce gametes as

In Morgan's experiment, what is the percentage of parental type offspring in F₂ generation in case of body colour and eye colour:-

Bateson used the terms coupling & repulsion while discovering linkage in 'Lathyrus'. If A and B are dominant alleles and a and b are recessive alleles of two genes, then parental crosses in coupling & repulsion phases can be written as follows:-

How much linkage strength is present between two genes A & B, which are 6 cM far from each other in a chromosome?

The experiment carried out by Morgan is shown in the figure to explain the phenomenon of linkage and recombination. If in cross-I, genes are tightly linked and in cross-II, genes are loosely linked then what will be the percentage of recombinants produced in cross-I and cross-II respectively?

A condition where an individual heterozygous for two pairs of linked genes (AaBb) possesses the two dominant genes on one homologous chromosome pair and two recessive on the other it is said to be