Question
Answer the following questions:
How did Morgan show the deviation in inheritance pattern in Drosophila with respect to this law?
How did Morgan show the deviation in inheritance pattern in Drosophila with respect to this law?
✓
Answer
Linkage and Recombination:
- T. H. Morgan carried out several dihybrid crosses in Drosophila to study the genes that are sex–linked. He observed that when the two genes in a dihybrid cross are located on the same chromosome, the proportion of parental gene combinations in the progeny was much higher than the non-parental or recombination of genes.
- Morgan and his group found that when genes are grouped on the same chromosome, some genes are tightly linked or associated and show little recombination.
- Linkage: Results of two dihybrid crosses conducted by Morgan. Cross A shows crossing between genes y and w; Cross B shows crossing between genes w and m. Here dominant wild type alleles are represented with (+) sign in superscript.
- When the genes are loosely linked they show higher percentage of recombination.
- Morgan hybridised yellow bodied and white eyed females with brown bodied and red eyed males (wild type) (cross–A) and inter–crossed their $F_1$ progeny.
- Alfred Sturtevant determined that genes of Drosophila are arranged in a linear order. He measured the distance between genes and prepared chromosome maps with the position of genes on the chromosomes based on percentage of recombinants. These are also called genetic maps.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
a. Draw a diagram of a fully developed embryo sac of an angiosperm. Label its chalazal end and any other five parts within the embryo sac.
b. Why does the development of an endosperm precede that of the embryo in angiosperm?
c. Number of chromosomes in an onion plant cell is 16. Name the cells of the embryo sac having 16 and 24 chromosomes formed after fertilisation.
b. Why does the development of an endosperm precede that of the embryo in angiosperm?
c. Number of chromosomes in an onion plant cell is 16. Name the cells of the embryo sac having 16 and 24 chromosomes formed after fertilisation.
(i) Define net primary productivity.
(ii) Explain with diagram that the pyramid of energy is always upright.
(ii) Explain with diagram that the pyramid of energy is always upright.
Do you think microbes can also be used as source of energy? If yes, how?
Who revealed biochemical nature of the transforming principle? How was it done?
Explain insertional inactivation.
- Differentiate between: Autogamy, Geitonogamy and Xenogamy.
- Explain the events that occur during pollen-pistil interaction.
Describe the main idea behind the biological control of pests and diseases.
What is organic farming? Discuss the benefits of organic farming as a viable practise in the context of developing nations like India.
Study the graph given below and answer the questions that follow:
Name the hormones ‘X’ and ‘Y’.
Name the hormones ‘X’ and ‘Y’.
What is Implantation? Describe the process of implantation with diagram.