Genomes Flashcards
What is a genome?
A: A genome is the complete set of genetic material (DNA) in an organism, including all of its genes and non-coding sequences.
What is the Central Dogma of Molecular Biology?
A: The Central Dogma states that DNA is transcribed into RNA, which is then translated into proteins.
What are exons and introns?
A: Exons are coding sequences in genes that are expressed as proteins, while introns are non-coding sequences that are spliced out during mRNA processing.
What is codon bias?
A: Codon bias refers to the preference of certain codons over others in an organism, affecting translation efficiency.
What are the key steps in DNA sequencing?
A: DNA is fragmented, adapters are added, fragments are sequenced, and overlapping reads are assembled into a continuous sequence.
Only 2-3% of the human genome codes for
proteins.
There are ~23,000 protein-coding genes in the
human genome.
Codon redundancy makes the genetic code
degenerate.
The human haploid genome is ~3 billion
base pairs (bp) long.
Next-Generation Sequencing (NGS) allows high-
throughput genome sequencing.
The genome perfectly maps onto the proteome.
False – Alternative splicing and RNA editing can modify protein expression.
Exons are always longer than introns.
False – Introns are often much larger than exons.
The genetic code is universal across all living organisms.
True – Although slight variations exist, the genetic code is nearly universal.
The first genome sequenced was bacterial.
True – The first complete genome sequenced was for a bacterial species.
The process of removing introns from pre-mRNA is called __________.
A: Splicing.
A DNA sequence that marks the start of transcription is called a __________.
A: Promoter.
The enzyme that synthesizes RNA from a DNA template is __________.
A: RNA polymerase.
The sequence of three nucleotides in mRNA that codes for an amino acid is called a __________.
A: Codon.
What is the role of tRNA in translation?
A) Forms the ribosomal subunits
B) Carries amino acids to the ribosome
C) Synthesizes mRNA
D) Edits introns out of pre-mRNA
A: B) Carries amino acids to the ribosome.
Which of the following is NOT a stop codon?
A) UAA
B) UGA
C) AUG
D) UAG
A: C) AUG.
What technique is used to assemble DNA sequencing reads?
A) PCR
B) Electrophoresis
C) Genome assembly
D) Cloning
A: C) Genome assembly.
Which chromosome region is typically gene-rich?
A) Heterochromatin
B) Centromere
C) Euchromatin
D) Telomere
A: C) Euchromatin.
A scientist is analyzing a eukaryotic genome and finds a long DNA sequence without stop codons. What is this region likely to be?
A: An open reading frame (ORF).
A researcher finds that two organisms share a highly conserved gene. What does this suggest?
A: The gene is functionally important and has been maintained through evolution.
