bio Flashcards
What is the primary focus of molecular biology?
Study of gene structure and function at the molecular level
Which of the following molecules are critical for all life according to molecular biology?
DNA, RNA, and Proteins
What is a gene?
The basic physical and functional unit of heredity
Who presented the structure of the DNA-helix in April 1953?
James Watson and Francis Crick
What is the central dogma of molecular biology?
DNA → RNA → Protein
What are the building blocks of DNA?
Nucleotides
Which of the following is NOT a component of a nucleotide?
Amino group
What is the difference between ribose and deoxyribose?
Ribose has an extra oxygen atom at the 2’ position
Which of the following bases is found in RNA but not in DNA?
Uracil
What type of bond holds the two strands of DNA together?
Hydrogen bonds
Which form of DNA is most commonly found in cells under normal conditions?
B-DNA
What is DNA supercoiling?
The over- or under-winding of a DNA strand
Which of the following is a function of ribosomal RNA (rRNA)?
Catalyzing the formation of peptide bonds
What is the role of transfer RNA (tRNA)?
To read the genetic code and place the correct amino acid in the sequence
Which of the following is NOT a type of RNA?
dRNA
What is the primary structure of RNA?
The sequence of nucleotides
What is a pseudoknot in RNA structure?
A type of tertiary structure
Which of the following is true about RNA structure stability?
The number of GC base pairs affects stability
What is the function of messenger RNA (mRNA)?
To carry genetic information that will be expressed as proteins
Which of the following is a characteristic of RNA?
It tends to be single-stranded
What is the role of microRNAs (miRNAs)?
To target mRNA for degradation and silence gene expression
Which of the following is NOT a feature of RNA?
It is double-stranded
What is the significance of the 5’ and 3’ ends in nucleic acids?
They define the ends of the polynucleotide chain
Which of the following is true about the antiparallel nature of DNA strands?
The strands are complementary and run in opposite directions
What is the role of topoisomerases in DNA supercoiling?
They change DNA topology to facilitate functions like replication and transcription
Which of the following is a characteristic of Z-DNA?
It has a zigzag arrangement of the sugar-phosphate backbone
What is the function of the sugar-phosphate backbone in DNA?
To provide structural support and protect the bases
Which of the following is true about the genotype of an organism?
It is the genetic makeup of an organism
What is the role of the ribosome in protein synthesis?
To catalyze the formation of peptide bonds
Which of the following is true about the structure of RNA?
It can form secondary structures like stem-loops
