Congenital malformations are caused by which of the following mutagens?

Damages and errors in the DNA can cause___________

• Mutation can be beneficial or harmful depending upon the impact it has produced on the organism

5-bromouracil is the analog of which base?

• Base analogues are naturally occurring molecules having similar structure to common bases
• 5BromoUracil and 2AminoPurine are common base analogues

Nitrous acid is a __________ agent.

Nitrous acid also converts adenine to hypoxanthine and guanine to xanthine

DNA is sensitive to temperatures above _______.

• PCR was discovered by Kary Mullis
• Various forms of PCR are available which are all based on the basic three steps 
• Besides replication, PCR can also be used in diagnosis, modification of genetic material, paternity testing and many more

Ionizing radiations include:

• Mutagens are the factors that cause mutation
• Physical mutagens include ionizing radiations, high concentration of carbon dioxide, etc

Generally, the mutations are:

• In harmful mutation, due to insertion or deletion of a base the resulting protein synthesis become faulty
• In silent mutation, the alteration in base sequence is such that the final protein is not changed

Which of the following base analogs exhibit tautomerism?

• Base analogues have structure similar to the common bases (Adenine, guanine, cytosine and thymine)
• 5bromouracil is the base analogue for thymine

Point Mutation is caused by:

• Point mutation can be caused due to substitution by a base analogue or due to exposure to ionizing radiations as well
• Point mutation can also be due to deletion or insertion of a base pair

Examples of base analogs are ________.

• Base analogues are naturally occurring molecules having similar structure to common bases
• 5BU has structure similar to thymine
• 2aminopurine has structure similar to purine

Alkyl bases are induced in DNA by which chemical mutagen?

• The alkylating agents helps in crosslinking of DNA which cannot replicate 
• Other mechanism is by replacing hydrogen atoms of DNA with alkyl groups which cannot be repaired by the cell

Base analogs are which type of mutagens?

• Bases are classified into purine and pyrimidine
• Purine include adenine and guanine which are two ringed structures
• Pyrimidine include thymine and uracil which are single ringed structures

Ionizing radiation causes ___________.

• Ionizing radiations have shorter wavelength but high energy
• Ionizing radiations cause single strand break or crosslinking

If the mutation occurs in the non-functional part of DNA, then these mutations may remain as _________.

• Silent mutation does not affect the individual since the change in the nucleic acid sequence doe not alter the amino acid produced.

Mutations are mainly responsible for:

• Not all mutations are harmful
• Some mutations are silent, having no effect
• Development of lactose tolerance is an example for beneficial mutation

_______ is the most mutagenic among UV rays.

• UV B and UV C have mutagenic effects
• The UV C radiations are filtered by the atmosphere
• Transition mutation is caused by UV C