Question:
A progeny drosophila with grey body and vestigial wings derived from a cross between parents with grey body and normal wings with black body and vestigial wings indicate:
(A). There is recombination between alleles of body color and types of wings of drosophila
(B). These two genes assort independently
(C). These genes are linked together
(D). These genes are pleiotropic in nature
Choose the correct answer from the options given below:
A progeny drosophila with grey body and vestigial wings derived from a cross between parents with grey body and normal wings with black body and vestigial wings indicate:
(A). There is recombination between alleles of body color and types of wings of drosophila
(B). These two genes assort independently
(C). These genes are linked together
(D). These genes are pleiotropic in nature
Choose the correct answer from the options given below:
(A). There is recombination between alleles of body color and types of wings of drosophila
(B). These two genes assort independently
(C). These genes are linked together
(D). These genes are pleiotropic in nature
Choose the correct answer from the options given below:
Show Hint
In linkage testcrosses, the appearance of non-parental phenotypes directly confirms homologous recombination (crossing over) between linked genes.
Updated On: Jul 31, 2026
- (A) and (C) only.
- (A), (B) and (C) only.
- (A), (B), (C) and (D).
- (B) and (C) only.
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
Linked genes are physically located close to each other on the same chromosome and tend to be inherited together.
Recombination occurs through crossing over during meiosis, which swaps segments of homologous chromosomes to produce non-parental allele combinations.
Step 2: Detailed Explanation:
In Drosophila melanogaster, the gene for body color and the gene for wing shape are linked on Chromosome II.
Let the dominant alleles be \(b^+\) (grey body) and \(vg^+\) (normal wings), and the recessive alleles be \(b\) (black body) and \(vg\) (vestigial wings).
A cross between a dihybrid parent (\(b^+ b \, vg^+ vg\)) and a double recessive parent (\(b b \, vg vg\)) is a genetic testcross.
If these genes assorted independently, a 1:1:1:1 phenotypic ratio of all combinations would be observed.
Because they are linked, parental types (grey-normal and black-vestigial) appear in much higher frequencies.
The appearance of grey body and vestigial wings (\(b^+ b \, vg vg\)) represents a recombinant phenotype.
This demonstrates that recombination has occurred between these alleles through crossing over, validating Statement (A).
The physical linkage of these genes explains why they do not assort independently, confirming Statement (C) and rendering Statement (B) incorrect.
Pleiotropy refers to a single gene affecting multiple distinct phenotypic traits, which is not applicable here since two separate loci control these traits, making Statement (D) incorrect.
Thus, only statements (A) and (C) are biologically correct.
Step 3: Final Answer:
Hence, the correct option is (A).
Linked genes are physically located close to each other on the same chromosome and tend to be inherited together.
Recombination occurs through crossing over during meiosis, which swaps segments of homologous chromosomes to produce non-parental allele combinations.
Step 2: Detailed Explanation:
In Drosophila melanogaster, the gene for body color and the gene for wing shape are linked on Chromosome II.
Let the dominant alleles be \(b^+\) (grey body) and \(vg^+\) (normal wings), and the recessive alleles be \(b\) (black body) and \(vg\) (vestigial wings).
A cross between a dihybrid parent (\(b^+ b \, vg^+ vg\)) and a double recessive parent (\(b b \, vg vg\)) is a genetic testcross.
If these genes assorted independently, a 1:1:1:1 phenotypic ratio of all combinations would be observed.
Because they are linked, parental types (grey-normal and black-vestigial) appear in much higher frequencies.
The appearance of grey body and vestigial wings (\(b^+ b \, vg vg\)) represents a recombinant phenotype.
This demonstrates that recombination has occurred between these alleles through crossing over, validating Statement (A).
The physical linkage of these genes explains why they do not assort independently, confirming Statement (C) and rendering Statement (B) incorrect.
Pleiotropy refers to a single gene affecting multiple distinct phenotypic traits, which is not applicable here since two separate loci control these traits, making Statement (D) incorrect.
Thus, only statements (A) and (C) are biologically correct.
Step 3: Final Answer:
Hence, the correct option is (A).
Was this answer helpful?
0
0
Top ICAR AIEEA Plant Biotechnology Questions
- Which of the following molecules can be classified under glycosphingolipid category?
- The bicarbonate buffer is a principal buffering system in blood plasma. The ratio of the bicarbonate to carbonic acid required to maintain pH of plasma at 7.4 is:
- Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): The disruption of $\beta$-oxidation of fatty acids in plants can potentially reduce stress-induced ROS accumulation and improve its stress tolerance.
Reason (R): In plants, $\beta$-oxidation of fatty acids takes place predominantly in peroxisomes, where first enzyme of $\beta$-oxidation viz. fatty acyl CoA oxidase produces large amounts of hydrogen peroxide.
In light of the above statements, choose the correct answer from the options given below. - The serum level of which of the following metabolites can effectively distinguish "Vitamin B12 deficiency" from "Folate deficiency" ?
- Match List-I with List-II
List-I (Name of the Enzyme) & List-II (Class of the enzyme)
(A). Pyruvate carboxylase & (I). Oxidoreductase
(B). Fumarase & (II). Hydrolase
(C). Phospholipase & (III). Lyase
(D). Nitrogenase & (IV). Ligase
Choose the correct answer from the options given below:
View More Questions
Top ICAR AIEEA Genetics Questions
- In a monohybrid cross, which of the following is always completely heterozygous?
- The process in eukaryotes that results in the production of gametes is
- A situation where each allele produces a protein that can be detected in the heterozygote is called
- The number of linkage group in a particular plants species is equal to the
- In the cross AaBb x aabb if incomplete dominance is exhibited at both the loci, what genotypic ratio is expected in the resulting offspring?
View More Questions
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?
View More Questions