Linkage and Crossing Over

The phenotype of the following fruit fly is:

Morgan gave linkage in which year?

A test cross of F₁ flies, $\frac{+ \mathrm{a}}{+ \mathrm{b}}$ produced the following offspring:

$$\begin{gathered} \frac{++}{\mathrm{a} \mathrm{b}}=9 \\ \frac{{\displaystyle \mathrm{a} \mathrm{b}}}{{\displaystyle \mathrm{a} \mathrm{b}}}=9 \\ \frac{{\displaystyle +\mathrm{b}}}{{\displaystyle \mathrm{a} \mathrm{b}}}=41 \\ \frac{{\displaystyle \mathrm{a}+}}{{\displaystyle \mathrm{a} \mathrm{b}}}=41 \end{gathered}$$

What will be the distance between linked gene: 

In a linear chromosome, map distance between for the loci are as follows:

$\mathrm{p} - \mathrm{q} = 20; \mathrm{q} - \mathrm{r} = 8; \mathrm{p} - \mathrm{s} = 6; \mathrm{p} - \mathrm{r} = 12$. The cross over frequency between r and s is:

Choose correct statements from the following:

A) The frequency of recombination between gene pairs on different chromosomes is the measure of distance between those genes.

B) Drosophila completes its life cycle in about two weeks.

C) deVries, Correns, and Morgan rediscovered Mendel's results.

D) Due to the visualization with staining, the term chromosome was coined.

In a dihybird cross between two heterozygotes, AaBb x AaBb, if we get 3:1 ratio among the offspring, the reason for this may be:

Match the following.

A plant heterozygous for height and flower colour $\left(\mathrm{TtRr}\right)$ are selfed and $1600$ of the resulting seeds are planted. If the distance between the loci controlling height and the flower colour is $1$ centiMorgan (cM), then how many offsprings are expected to be short with white flower $\left(\mathrm{ttrr}\right)$$?$ 

Choose the wrong statement.

A.  A single gene product may produce more than one effect thus it relates to pleiotropy

B. Dominance is an autonomous feature of a gene or the product

C. The frequency of recombination between gene pairs on the same chromosome as a measure of distance between those genes

D. Breeder cannot select the mutations of the desirable types as it has less variability

The correct answer is

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

The two genes are $70 \mathrm{cM}$ apart. Then the frequency of recombination is:

Which of the following is not true about linkage considering body colour and eye colour of the fruit fly, in the experiment performed by Morgan?

The percentage of the F₂ generation offspring showing parental character for the body colour and eye colour in Morgan's experiment is:

Genes located very close to one another on the same chromosome tend to be transmitted together and are called _____.

Mendel's law of independent assortment does NOT hold true for the genes that are located closely on

Distance between gene and percentage of linkage shows:

All genes located on the same chromosome ______.

True-breeding red-eyed Drosophila flies with plain thorax were crossed with pink-eyed flies with striped thorax.

$\begin{array}{ccc}\mathrm{Red-eye} \mathrm{and plain} thorax & \mathrm{X }& \mathrm{P}\mathrm{i}\mathrm{n}\mathrm{k-}\mathrm{e}\mathrm{y}\mathrm{e} \mathrm{and} \mathrm{striped} thorax\end{array}$

The ${\mathrm{F}}_1$ flies were then test crossed against the double recessive.

The following F2 generation resulted from the cross:
 

A. The physical association between the two genes is termed as $\text{\_\_\_\_a\_\_\_\_}$.
B. The generation of non-parental gene combination is termed as $\text{\_\_\_\_b\_\_\_\_}$ .

In an experiment, $\mathrm{A}\mathrm{a}\mathrm{B}\mathrm{b\; obtained\; in\; the}\mathrm{ }\left(\mathrm{F}1\right)$ generation was test crossed. In the progeny, genotype Aabb and aaBb were more frequent than AaBb and aabb. Then the genotype of the parents should be