Gene,Transcription,Traslation Flashcards
(30 cards)
What is a gene?
A gene is a sequence of nucleotides along a DNA molecule controlling the expression of a character, mostly proteins.
What are the two types of sequences found in a gene?
- Coding sequences (exons)
- Non-coding sequences (introns)
What is the role of RNA in the cell?
RNA acts as a messenger molecule between DNA in the nucleus and protein synthesizing machines in the cytoplasm.
What is transcription?
Transcription is the process by which a specific DNA sequence is used as a template to synthesize a complementary RNA molecule.
What is the transcribed strand of DNA?
The strand used as a template for transcription.
What enzyme is responsible for transcription?
RNA polymerase.
What is pro-mRNA?
Pro-mRNA is an immature RNA molecule formed during transcription, consisting of both exons and introns.
What happens during pro-mRNA processing?
Introns are excised and the remaining exons are ligated to form mature mRNA.
Where does translation occur?
In the cytoplasm.
What role does t-RNA play in translation?
t-RNA transfers amino acids to the sites of ribosomes during translation.
What is a missense mutation?
A missense mutation causes the change of the coded amino acid, potentially altering the protein’s function.
What is a nonsense mutation?
A nonsense mutation changes an amino acid coding codon to a stop codon, leading to early termination of translation.
What is a frameshift mutation?
A frameshift mutation results from the insertion or deletion of nucleotides, altering downstream codons and protein function.
What are silent mutations?
Silent mutations do not affect the amino acid sequence of a protein and thus do not change its function.
What is the definition of mutation?
A mutation is the alteration in nucleotide sequence of a gene (DNA).
What are the two main types of mutations?
- Spontaneous mutations
- Induced mutations
What is the effect of a substitution mutation?
It replaces one nucleotide with another, potentially altering the amino acid sequence.
What type of mutation is caused by X-rays and UV rays?
Induced mutations.
What determines whether a mutation is effective or silent?
Its effect on the amino acid sequence of the protein and its function.
What is the consequence of a frameshift mutation?
It alters downstream codons, potentially changing the protein’s function.
What is the significance of mutations in sex cells?
Only mutations in sex cells can be transmitted from parents to children.
What is the ultimate effect of mutations on genetic diversity?
They can lead to polymorphism of genes and contribute to genetic diversity.
What are the consequences of effective mutations?
- Missense Mutation
- Nonsense Mutation
- Frameshift Mutation
What are the consequences of silent mutations?
- Mutation in introns
- Mutation that changes a codon to another coding for the same amino acid
- Mutation in switched off genes
- Mutation in recessive alleles
