A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as
- TTWW
- TTww
- TtWW
- TtWw
The Correct Option is C
Solution and Explanation
The genetic make-up of the tall parent can be depicted as TtWW Since all the progeny bore violet flowers, it means that the tall plant having violet flowers has WW genotype for violet flower colour. Since the progeny is both tall and short, the parent plant was not a pure tall plant. Its genotype must be Tt.
Therefore, the cross involved in the given question is
TtWw×ttww
\(\downarrow\)
TtWw−ttww
Therefore, half the progeny is tall, but all of them have violet flowers.
Top Questions on Heredity
- How is the equal genetic contribution of male and female parents ensured in the progeny?
- CBSE Class X
- Science
- Heredity
- Outline a project which aims to find the dominant coat colour in dogs.
- CBSE Class X
- Science
- Heredity
- A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?
- CBSE Class X
- Science
- Heredity
Questions Asked in CBSE X exam
- Enumerate the benefits of having an access control system installed in a premise.
- CBSE Class X - 2024
- Security Structure
- Enlist any four formatting options provided by Gmail for you to compose an email.
- CBSE Class X - 2024
- Email Messaging
- You are a security supervisor in a hospital. Your security manager has asked you to check the signage system in the hospital building and prepare a report. What all aspects would you check in this regard?
- CBSE Class X - 2024
- Security Structure
- Write about any two provisions of Rajiv Gandhi Shramik Kalyan Yojna, 2005.
- CBSE Class X - 2024
- Laws Governing Private Security
- Why are ground search and rescue services increasingly required in urban and sub-urban areas to locate which persons?
- CBSE Class X - 2024
- Disaster Management and Emergency Response
Concepts Used:
Principles of Inheritance and Variation - Mutation
A Mutation is a change in the sequence of our DNA base pairs caused by numerous environmental stimuli such as UV light or mistakes during DNA replication. Germline mutations take place in the eggs and sperm and can be passed onto offspring, whereas somatic mutations take place in body cells and are not passed on.
Types of Mutations
There are three types of mutations, which are as follows:
Silent mutation
It refers to any change in DNA sequence that has no effect on the amino acid sequence in a protein or the functions that a protein performs. There is no phenotypic indication that a mutation has occurred.
Nonsense mutation
When there is a change in the sequence of base pairs due to a point mutation, that results in a stop codon. This leads to a protein that is either shortened or non-functional.
Missense mutation
A missense mutation occurs when a point mutation causes a change in the codon, which then codes for another amino acid.
The mutation is caused by the following factors:
Internal Causes
When DNA copies incorrectly, the majority of mutations occur. Evolution occurs as a result of all of these mutations. DNA makes a copy of itself during cell division. When a copy of DNA isn't flawless, it's called a mutation since it differs somewhat from the original DNA.
External Causes
When certain chemicals or radiations are used to break down DNA, it causes the DNA to break down. The thymine dimers are broken by UV radiation, resulting in altered DNA.