BIOSCI 202 Genetics: Lectures 11-12 Causes and Effects of Mutations; Lab, Regulation, Transposons (Fill-in-the-Blank Flashcards)

Fill-in-the-blank flashcards covering key concepts from the mutation-focused and regulation/transposon lecture content.

The proofreading activity of DNA polymerase that ensures high fidelity during DNA replication is called __.

proofreading

Cytosine deamination is a spontaneous base change that converts C to __, leading to C=>T transitions.

uracil (U)

Methylcytosine deamination converts 5-methylcytosine to __, contributing to C→T transitions over time.

thymine

Non-natural bases that can substitute for natural bases in DNA, such as 2-aminopurine, are called __ mutagens.

base analog

5-bromouracil mutagen can pair with A or G and requires two rounds of replication to produce full mutation; it is a __ mutagen.

base-analog mutagen

Benzo[a]pyrene is activated by cytochrome P450 and binds irreversibly to G in DNA; it is a mutagen found in __ smoke.

cigarette

Radiation induces breaks in DNA, making radiation a powerful __.

mutagen

A synonymous mutation is also called a __ mutation.

silent

A mutation that changes the amino acid encoded by a codon is called a __ (missense) mutation.

nonsynonymous

A mutation that creates a stop codon is a __ (nonsense) mutation.

nonsense

Insertions or deletions that disrupt the reading frame are called __ mutations.

frameshift

Mutations in promoter or regulatory regions that affect expression are referred to as __ mutations.

regulatory

The continuum of mutation effects ranges from deleterious to neutral to beneficial; this is described as a __ of mutation effects.

continuum

Regions with a high degree of sequence conservation across species are likely to be functionally important; this concept is called __.

conservation

The Luria-Delbrück fluctuation test showed that mutations are __ and pre-existing rather than induced by exposure.

pre-existing

Humans have about 20 million base differences between individuals and roughly 100–200 __ mutations per person.

de novo

Most genetic diseases are caused by __ variants, not by new mutations.

pre-existing

In a plaque assay, the number of plaque-forming units is denoted as __.

Pfus

The latent period in phage infection is the time between infection and the first __.

burst

The number of phage produced per infected cell is called the __.

burst size

The inducer of the lac operon is __ (allolactose).

allolactose

In lac regulation, the CAP-cAMP complex serves as a positive regulator; high glucose lowers cAMP and reduces CAP activity; this mechanism is called __.

catabolite repression

The -35 promoter box consensus sequence is __.

TTGACA

The -10 promoter box consensus sequence is __.

TATAAT

RNA polymerase promoter recognition in bacteria is mediated by the __, which recognizes specific promoter sequences.

sigma factor (σ70)

Promoter spacing between the -35 and -10 elements is important for transcription; this distance is called the promoter __.

spacer

Mediator is a multiprotein complex that helps activate transcription by bridging transcription factors and RNA polymerase II.

Mediator

In yeast GAL system, GAL4 is the activator; its activity is regulated by GAL80 (repressor) and GAL3 (galactose sensor); which gene encodes the galactose sensor? __

GAL3

DNA methylation in promoters is generally associated with transcriptional __.

repression

Chromatin can be in an open, transcriptionally active form called (euchromatin), or a condensed, transcriptionally silent form called (heterochromatin).

euchromatin; heterochromatin

Histone acetylation is usually associated with activation of transcription; methylation can either activate or repress depending on context. The modifying process is called __ histone modification.

acetylation

Position effect variegation demonstrates context-dependent gene expression due to chromatin state; classic example involves the Drosophila __ gene.

white

Three-dimensional organization of the genome includes regions called __ (topologically associated domains).

topologically associated domains (TADs)

UASG stands for upstream activation sequence used in the GAL system; GAL4 binds UASG to activate transcription. What does UASG stand for?

upstream activation sequence (UASG)

Transposons encode an enzyme that catalyzes movement; this enzyme is called __.

transposase

Transposon termini often contain __ repeats that bind transposases.

inverted repeats

When a transposon inserts into a genome, it often creates short direct repeats at the insertion site called __.

target site duplications

Transposons can be categorized into two main classes: Class I retrotransposons and Class II __ transposons.

DNA (Class II)

Autonomous transposons encode the transposase and can catalyze their own movement; non-autonomous transposons do not and rely on autonomous elements. The term for the self-sufficient type is __ transposons.

Autonomous

LINEs, SINEs, and LTRs are major human retrotransposons; LINEs encode reverse transcriptase and are __ elements.

autonomous