Molecular_Genetics_Study_Flashcards
DNA is a polymer – what is the monomer that DNA is made of?
Nucleotide
What are the three parts of every nucleotide?
Phosphate group, deoxyribose sugar, nitrogenous base
What are the four nitrogen bases in DNA?
Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
What are the base pairing rules for DNA?
A pairs with T, C pairs with G
How does DNA replication occur?
The DNA double helix unwinds, and each strand serves as a template for a new strand.
What does DNA have the instructions for making?
Proteins
What is a gene?
A segment of DNA that codes for a protein or functional RNA
What are the two main steps in protein synthesis?
Transcription and Translation
Explain what happens in transcription (and where in a cell this occurs).
In transcription, the DNA is used to create a complementary mRNA strand in the nucleus.
How are the base pairing rules for RNA different from the base pairing rules for DNA?
In RNA, uracil (U) pairs with adenine (A) instead of thymine (T).
What messenger RNA (mRNA) sequence would be made from this strand of DNA? AAT GCA CAG TTA
UUA CGU GUC AAU
What is the “protein factory” called?
Ribosome
Explain what happens in translation. And what role does tRNA play in translation?
In translation, the mRNA is read by the ribosome, and tRNA brings the corresponding amino acids.
What is a mutation?
A change in the DNA sequence that can affect gene function.
What is the difference between a base substitution mutation, and an addition or deletion mutation?
Base substitution changes one base, while addition or deletion adds or removes a base from the sequence.
Why does a base addition or deletion always change the amino acid sequence?
It shifts the reading frame, changing the sequence of codons and thus the amino acid sequence.
One possible effect of a mutation is that it could be neutral (no change). What are the other two possible effects, which one is more common, and why is it more common?
The other two effects are beneficial and harmful. Harmful is more common because mutations often disrupt gene function.
What are STR’s, and how can they be used to identify someone?
STRs (Short Tandem Repeats) are repeating sequences of DNA that vary in length among individuals, used for identification.
List 2 reasons why we might test someone’s DNA.
To diagnose genetic disorders, for forensic analysis.
List 3 ways that we use genetic engineering to improve our lives.
Creating genetically modified crops, producing insulin, gene therapy for diseases.
What is CRISPR, and (basically) how does it work?
CRISPR is a gene-editing technology that uses a guide RNA to target specific DNA sequences for modification.
