Prepare for NEET Biology Molecular Basis of Inheritance with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert explanations of DNA replication and genetics.
The RNA world hypothesis suggests that self-replicating RNA molecules were crucial for the origin of life. What is a major challenge to the idea of self-replicating RNA?
RNA's inherent stability
The simplicity of RNA's structure
The abundance of free nucleotides in early Earth environments
The complexity of RNA replication without enzymatic assistance
Which feature of some RNA molecules supports their potential role as early catalysts?
Linear, unfolded structure
Inability to bind to other molecules
Specific three-dimensional structures
Lack of chemical reactivity
Why is the existence of the ribosome considered further evidence for the RNA world hypothesis?
Ribosomes are primarily composed of proteins.
Ribosomes synthesize DNA.
The catalytic core of the ribosome is made of rRNA.
Ribosomes are found only in eukaryotes.
The sequence of a template strand of DNA is 3'-TACGCT-5'. What is the sequence of the corresponding mRNA molecule?
5'-ATGCGA-3'
3'-AUGCGA-5'
5'-AUGCGA-3'
3'-TACGCT-5'
Which of the following statements about the genetic code is INCORRECT?
It is degenerate, meaning multiple codons can code for the same amino acid.
It is unambiguous, meaning each codon codes for only one specific amino acid.
It is universal, meaning it is mostly the same in all organisms.
It is overlapping, meaning a single base can be part of multiple codons.
A mutation changes a codon from UCU (Serine) to UCC (Serine). What type of mutation is this?
Missense mutation
Nonsense mutation
Frameshift mutation
Silent mutation
The start codon in most organisms codes for which amino acid?
Tryptophan
Valine
Methionine
Phenylalanine
If a mRNA sequence reads 5'-AUGUUUGCUAG-3', how many amino acids will the resulting polypeptide have?
1
2
3
4
The wobble hypothesis explains:
The universality of the genetic code.
The non-overlapping nature of the genetic code.
The degeneracy of the genetic code, particularly at the third base of a codon.
The mechanism of frameshift mutations.
