Genetics gene regulation.DNA methylation.gene mutation.DNA repair

Daughter strands may contain single-nucleotide additions and/or deletions, resulting in frameshifts.

A change in the structure of chromosomes that can affect gene expression.

The loss of a purine base (adenine or guanine) from DNA.

Methylation inhibits the binding of an activator protein.

CREB protein.

cAMP response element-binding.

Thymine dimers, chemically modified bases, missing bases, and some types of crosslinks.

In all eukaryotes and prokaryotes.

An imbalance between the production of ROS and an organism’s ability to break them down.

Direct repair fixes specific types of damage without removing nucleotides, while excision repair removes damaged sections before repairing.

A C-G to A-T mutation will result during subsequent rounds of DNA replication.

Gene Mutation and DNA Repair.

Alteration of gene expression due to a gene's new location.

They can affect the molecular and phenotypic expression of genes.

It is recruited by the activator/coactivator complex to the core promoter.

Unmethylated, hemimethylated, and fully methylated.

It binds to DNA and stimulates transcription.

5’ - TGACGTCA - 3’ and 3’ – ACTGCAGT - 5’.

Spontaneous mutations occur naturally, while induced mutations are caused by external factors.

They regulate the rate of transcription of target genes.

Because most mutations are deleterious.

To remove a damaged base from DNA.

1,000 to 2,000 nucleotides long.

They can have various effects on the polypeptide.

It can affect whether a given mutation is deleterious or beneficial.

Secreted into the bloodstream.

Cis regulatory elements located near the core promoter.

DNA methyltransferase.

A change in a single base pair.

Uracil as an inappropriate base.

It has short wavelength and high energy.

The formation of uracil, which can lead to mutations if not repaired.

McGraw Hill.

Transcriptional silencing via methylation.

Substances that become incorporated into daughter strands during DNA replication.

Regulatory sequences can cause gene A to show the expression pattern of gene B.

They are required for the binding of RNA polymerase to the core promoter and its progression to the elongation stage.

Pairing with guanine.

5’ AACGCTAGATC 3’ changing to 5’ AAC AGTC GCTAGATC 3’.

Multimeric proteins.

Regions with a high concentration of phosphate-linked cytosine-guanine pairs found near many gene promoters in vertebrates and plants.

It is the conversion of cytosine into uracil by the removal of an amine group.

The elongation phase.

DNA polymerase may insert an incorrect base, leading to mutations.

Mutations that affect the phenotype only under a defined set of conditions.

A temperature-sensitive mutation.

DNA methylation is the addition of a methyl group to the DNA molecule, typically at cytosine bases.

Acts as a second messenger.

The elongation phase.

A defect in one enzyme may be compensated for by a mutation that enhances another enzyme's function.

DNA where only one strand is methylated.

Steroid receptors.

Mutations that occur in gametes and are passed to half of the gametes in the next generation.

To affect gene transcription.

Both parental strands are methylated.

The removal of a purine (guanine or adenine) from DNA, forming an apurinic site.

Glucose utilization, fat mobilization, and protein breakdown.

Increased sensitivity to sunlight and predisposition to skin cancer.

Base substitutions that change a normal codon to a stop codon.

They distort the helical structure of DNA.

The carboxyl-terminal domain of RNA polymerase.

Chemically reactive molecules termed free radicals.

It recruits other proteins that change the chromatin to a closed conformation.

A general process for DNA repair that removes damaged DNA segments.

Transcriptional repression occurs via the inhibition of TFIID.

To fix damaged DNA and maintain genomic integrity.

They are necessary for basal transcription.

Mutagens.

cAMP response element (CRE).

To remove bulky DNA adducts and repair UV-induced damage.

Several DNA repair systems.

The parental strand is methylated while the newly made daughter strand is not.

Suppressor mutations that occur within the same gene as the first mutation.

Most regulatory transcription factors do not bind directly to RNA polymerase.

They can alter DNA structure and cause mutations by damaging the DNA bases.

Normal DNA is synthesized.

They are released.

1. Movement next to regulatory sequences 2. Movement to a heterochromatic region.

The process of turning off a gene to decrease its expression.

Transcription will be enhanced.

By covalent modification, specifically phosphorylation.

Addition and deletion of short sequences of DNA.

In prokaryotes.

The mismatch repair system corrects the error.

Base pair mismatches.

The most extreme type of deleterious mutations that result in death.

They influence the ability of RNA polymerase to begin transcription of a particular gene.

Breakages of chromosomes into pieces.

They covalently modify the structure of a nucleotide.

Adenine.

They are unmethylated.

The polypeptide produced by the gene.

They are taken up by cells that respond to the hormone.

The imino form.

They covalently modify base structure or disrupt pairing by alkylating bases.

A type of point mutation where one base pair is replaced by another.

A change of a pyrimidine (C, T) to another pyrimidine or a purine (A, G) to another purine.

Changes in chromosome structure, changes in chromosome number, and changes in DNA of a single gene.

Hormone.

Transcription is silenced.

A mutation that compensates for a defect in one enzyme by increasing the function of a different enzyme in the same pathway.

Cytosine bases are not methylated.

Yes, but it cannot activate RNA polymerase.

1. Depurination 2. Deamination 3. Tautomeric shift

Oxidative DNA damage.

The loss of a purine base from DNA, which can lead to mutations.

7,8-dihydro-8-oxoguanine (8-oxoG).

A chemical change that can cause spontaneous mutations.

They are specific to the newly made strand.

1. Binding of a small effector molecule, 2. Protein-protein interactions, 3. Covalent modification.

MutL, MutH, and MutS.

It may alter the ability of pre-mRNA to be properly spliced.

Uracil, 3-methyladenine, and 7-methylguanine.

They can disrupt appropriate pairing by alkylating bases within the DNA.

Chromosomal rearrangements and deficiencies.

Homologous recombination repair (HRR) and nonhomologous end joining (NHEJ).

Vertebrates and plants.

Transitions are more common than transversions.

Methylation of cytosine.

The removal of an amino group from the cytosine base.

X-rays and gamma rays.

The process of turning on a gene to increase its expression.

Transcriptional activation of a target gene.

An abnormality where an incorrect base is added during DNA replication.

The AT/GC rule of base pairing.

Regulatory sequences are often bidirectional.

Common pathway.

Hemimethylated GATC sites.

Mutations that reverse the phenotypic effects of another mutation.

The keto form.

The removal of an amino group from a nucleotide, which can result in base substitution mutations.

Repairing small, non-helix-distorting base lesions.

To remove damaged DNA segments.

Substances that cause mutations through chemical reactions, such as certain pesticides or alkylating agents.

They do not pair with the appropriate nucleotides in the daughter strand.

Early degeneration of the nervous system.

Regulation via Mediator.

Approximately 10,000 purines per 24 hours at 37 °C.

UV-induced damage and chemically damaged DNA.

An activator.

They recognize methylated sites and recruit other proteins that lead to chromatin compaction.

Closed chromatin prevents transcription by making DNA inaccessible to the transcription machinery.

The other bases besides cytosine.

Agents that contain flat planar structures that intercalate into the DNA double helix.

Base deletions, oxidized bases, single nicks in DNA strands, cross-linking, and chromosomal breaks.

DNA methylation can repress transcription by preventing the binding of transcription factors to the DNA.

Photolyase.

Byproducts produced by aerobic organisms, including hydrogen peroxide, superoxide, and hydroxyl radical.

5’ AACGC TAGA TC 3’ changing to 5’ AACGCTC 3’.

Mutations that decrease the chances of survival.

Superoxide dismutase and catalase.

It may increase or decrease the rate of transcription.

They help to block the buildup of Reactive Oxygen Species.

Due to the degeneracy of the genetic code.

DNA damage and mutation.

The earlier the mutation occurs, the larger the patch of affected area.

A chemical change that can result in spontaneous mutations.

Hormones that include estrogen and testosterone.

UvrA, UvrB, UvrC, and UvrD.

Mutations that occur directly in a body cell that is not part of the germ-line.

Seven different NER genes.

Nitrogen mustards and ethyl methanesulfonate (EMS).

Errors in DNA replication.

An enhancer.

A silencer.

Mediator.

It can penetrate deeply into them.

Protein-protein interaction.

RNA polymerase cannot proceed to the elongation phase of transcription.

DNA.

By their differential ability to survive.

They may function as enzymes that interact with each other.

Germ-line cells and somatic cells.

As chemical or physical mutagens.

They may alter the ability of mRNA to be translated or affect mRNA stability.

The covalent attachment of methyl groups to DNA.

The amino form.

Molecular changes in the DNA sequence of a gene.

Mutations involving the addition or deletion of nucleotides that is not divisible by three.

Because they are involved in Ultra violet light repair of pyrimidine dimers.

They can lead to alterations in gene regulation and expression levels.

Due to their stable and ubiquitous expression.

A change of a pyrimidine to a purine or vice versa.

HDACs remove acetyl groups from histones, leading to a more compact chromatin structure.

Acridine dyes and Proflavin.

It may affect the gene's function.

It inhibits the binding of TFIID to the core promoter or inhibits its function.

5-bromouracil, which is a thymine analog.

Cell-signaling molecules that increase cytoplasmic cAMP concentration.

Visible light.

A temporary change in base structure.

A DNA repair mechanism that removes damaged DNA segments.

They can be involved in the common pathway affected by mutations.

Enhance the survival or reproductive success of an organism.

A substance that causes mutations in DNA.

Ionizing radiation, chemical mutagens, and reactive oxygen species (ROS).

They can cause gene mutations that may have harmful effects.

An individual with somatic regions that are genotypically different from the rest of the body.

Base modifiers, intercalating agents, and base analogs.

R is a purine and Y is a pyrimidine.

They allow transcription factors to interact with co-activators, co-repressors, or other transcription factors, modulating their ability to bind DNA and influence activity.

It affects the transcription of an associated gene.

DNA polymerase and ligase.

Phosphorylation.

It can cause base-pair substitutions during DNA replication.

It interacts with mediator to prevent the phosphorylation of RNA polymerase.

Protein kinase A.

Mutations that occur in a different gene from the first mutation.

Direct repair and excision repair.

Base substitutions that do not alter the amino acid sequence of the polypeptide.

A type of chemical change that can lead to spontaneous mutations.

They result in patches of affected areas in the body.

Enhancers.

Gametes such as eggs and sperm.

An apurinic site.

They recognize an abnormal base and cleave the bond between it and the sugar in DNA.

Agents that cause mutations through physical means, such as radiation (e.g., UV light, X-rays).

The second mutation restores normal protein structure.

No, it is common in some but not all eukaryotic species.

A region of DNA with a high frequency of CpG sites, often located near gene promoters.

Methylation of CpG islands can silence gene expression by blocking the binding of activator proteins.

~ 2 to 7%.

Chemical or physical agents.

It recruits TFIID to the core promoter and/or activates its function.

General transcription factors and regulatory transcription factors.

By splitting the dimers.

A 3’ to 5’ proofreading ability to detect and fix base mismatches.

It can distinguish between the parental strand and the daughter strand.

Alkylated bases.

Both strands of DNA have methylated cytosine bases.

By transferring the methyl or ethyl group to a cysteine side chain within the protein.

They may disrupt the ability of the gene to be properly regulated.

By endocrine glands.

DNA N-glycosylases.

An irregularity in DNA structure is detected.

Mutations that occur directly in a sperm or egg cell, or in one of their precursor cells.

Somewhat unstable.

Because their absence leads to a much higher mutation rate than normal.

Control elements, regulatory elements, or regulatory sequences.

They are located near dozens of different genes, allowing the hormone to activate many genes.

A mutation may result during subsequent rounds of DNA replication.

It can block the binding of activator proteins, preventing gene activation.

Agents that are known to alter DNA structure.

1. They are often involved in the development of human cancers. 2. They can cause gene mutations that may have harmful effects in future generations.

In all species.

Xeroderma pigmentosum (XP) and Cockayne syndrome (CS).

The enol form.

Temporary changes in the structure of a nucleotide base that can lead to mispairing during DNA replication.

It replaces amino groups with keto groups, changing cytosine to uracil and adenine to hypoxanthine.

A transversion mutation (GC base pair to TA base pair).

Housekeeping genes.

It can change the amino acid sequence, potentially affecting the polypeptide's function.

It shifts the reading frame, resulting in a completely different amino acid sequence downstream of the mutation.

They directly interfere with the replication process.

They incorporate into DNA and disrupt its structure, with some tautomerizing at a high rate.

Influencing nutrient metabolism in most cells.

Suppressor mutations or simply suppressors.

TFIID acts as a general transcription factor that can regulate transcription either directly or through coactivators.

Base substitutions in which an amino acid change does occur.

5’ - AG R ACA - 3’ and 3’ - TC Y TGT - 5’.

A change in a single nucleotide in the DNA sequence.

10 to 100 breaks.

No, mutations are not present in gametes.

It is a multi-step process.

Phosphorylation, acetylation, or ubiquitination.

They can alter the transcription factor’s activity, stability, or ability to bind DNA, thereby influencing gene regulation.

It usually inhibits transcription.

They can bind to transcription factors, changing their shape or function, which can activate or inhibit gene regulation.

They are often involved in the development of human cancers.

They influence the growth and function of the gonads.

Mutations that result from abnormalities in cellular or biological processes.

UV light or X-rays.

Pesticides or alkylating agents.

Regulation via changes in chromatin structure.

Yeast and Drosophila.

It adds a random base.

A repressor.

They are essential genes consistently expressed in all cells, involved in basic cellular functions.

Germ-line mutations occur in reproductive cells and can be inherited, while somatic mutations occur in non-reproductive cells and are not passed to offspring.

From within the cell.

X-rays, gamma rays, ionizing radiation, and UV light.

Open (euchromatin) and closed (heterochromatin).

Environmental agents.