Minutagens. For example, if the codon GAA becomes the codon GAG, because the genetic code is degenerate, the codon will still code for the amino acid glutamate. Minutagens

 
 For example, if the codon GAA becomes the codon GAG, because the genetic code is degenerate, the codon will still code for the amino acid glutamateMinutagens  If the change in the deoxyribonucleotide base sequence results in transcription of a stop or nonsense codon, the protein would be terminated at that point in the message (Figure 19

Examples of potentially harmful environmental factors include toxic chemicals, X-rays and pollution. It is important to note that DNA damage, in and of itself, does not necessarily lead to the. The emergence, spread, and evolution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been chronicled by the scientific community with greater speed and depth than any other human pathogen due to the advent of widespread genomic sequencing. As many times the cells divide, they acquire more mutation. Two models have been proposed: "error-free" bypass of deaminated. As many mutations can. These mutagens may be carcinogens because numerous mutations can lead to cancer in animals, though not necessarily in all cases. Mutagens, either endogenous or exogenous, increase genetic mutation probability. The types of mutations include: Silent mutation: Silent mutations cause a change in the sequence of bases in a DNA molecule, but do not result in a change in the amino acid sequence of a protein (Figure 1). Both allelic variants, c. Mutations (changes in a gene sequence) can result in mutant alleles that no longer produce the same level or type of active product as the wild-type allele. There are 39 mutations to be acquired. Mutagens are often also carcinogens, agents that cause cancer. 8 months,. -survivability of the species. . This approach can be useful when it comes to a gene associated with a disease: the disease allele carries a mutation, a DNA change that compromises the protein's function. A germline mutation, or germinal mutation, is any detectable variation within germ cells (cells that, when fully developed, become sperm and ova ). Mutations can result from errors in DNA replication during cell division, exposure to mutagens or a viral infection. Some mutations harm an organism’s ability to survive and reproduce. Genetically, however, viruses have many features in common with cells. Combo attacks with swords have a chance to reduce stamina costs on further combos. Non-sense mutations create a stop codon, which can prevent the protein from being produced entirely, while. 00:36. Mutagens can be physical mutagens, chemical mutagens, or biological mutagens. In this Review, we present the Integrative OncoGenomics (IntOGen) pipeline, an implementation of such an approach to obtain the compendium of mutational cancer drivers. Making the dystrophin protein from the gene involves several steps. 2 This phenomenon is seen in the case of sickle cell. Cystic fibrosis is an inherited disorder. Makes every attack have a chance to land as a Critical Hit. 001. Mitochondrial genetics is different from Mendelian genetics in almost every aspect, from the uniparental inheritance of disease mutations, to the presence of many copies of the genome within a. In preclinical models, rapid recovery of MAPK pathway signaling has been associated with BRAF-inhibitor resistance, and complete inhibition of the MAPK pathway is needed to induce cell death in. A repeat expansion is a variant that increases the number of times that the short DNA sequence is repeated. Exposure to mutagens can cause induced mutations, which are various types of chemical agents or radiation (Table [Math Processing Error] 13. Our clinical variant data has been consolidated and shared with free publicly accessible databases such as ClinVar. 001. A chemical mutagen can either replace a base in DNA, alter a base's composition and pairing behavior, or damage the base so that it can no longer pair. Increases damage dealt with Axes. Hereditary mutations include cystic fibrosis, hemophilia, and sickle cell disease. In this introduction to more detailed papers that follow, we aim to provide an oversight of the field. Most of the mutations occur when the DNA fails to copy accurately. ”. This article provides an overview of mutation detection methods in genetic disorders, covering the principles, applications, advantages and limitations of each technique. The smallest changes, called point mutations, alter only a single base. Coup de Grass. Gain Hunger and Thirst 50% faster when moving. Whenever a player takes radiation damage, they have a chance to gain a mutation, equivalent to 5% per 5 points. The effects of some mutagens are potentiated. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. Acute myeloid leukemia (AML) accounts for ∼25% of all adult-onset leukemias in the Western world, with an incidence of 3 to 5 cases out of every 100 000 adults per year and a median age of 69 years at diagnosis. Most mutations are forward type. Mutations are essential to evolution; they are the raw material of genetic variation. 4 months and 9. Mutagens are often also carcinogen s, agents that cause cancer. Dystrophin has 79 exons, which makes it one of the largest genes in the body. 00:00. Carcinogenesis and mutagenesis processes and the relation between them are not completely understood but at present two mechanisms are considered: one inducing cancer by involving mutations (caused by genotoxic substances) and one that induces or promotes it by other means (caused by non. Germline mutations are changes to your DNA that you inherit from the egg and sperm cells during conception. CFTR MUTATION CLASSES Normal Class I Class II Class III Class IV Class V DESCRIPTION No functional CFTR is created. The Amaris has the most eyes out of any other dragon species, having a total of 7. The disorder causes severe damage to the digestive system, lungs, and other organs. Paul Andersen describes the major mutations found in the living world. It uses progressive JavaScript, is built with TypeScript and combines elements of OOP (Object Oriented Programming), FP (Functional. A mutation is a change in a genetic sequence. These mutagens cause point mutations, because they change the genetic code at one point, so changing a protein's amino acid sequence. We studied 879 PMF patients to determine the individual and combinatorial prognostic relevance of somatic mutations. Keep running until your teen is exhausted over. The long-term dynamics of IS elements and their. Methods. The lifetime risk for endometrial cancer is not increased in women with BRCA1 mutations, but there is a small increase in risk for this rare subtype. 96% had LoF mutations in MC4R (compared. Mutation and recombination can both be defined as processes that result in changes to a genome, but they are unrelated and we must make a clear distinction between them: A mutation ( Section 14. Technically, a mutation is defined as. There are several. They provide both positive and negative effects. All these chemical mutagens are strongly carcinogenic and extreme care should be taken while handling and disposal. The world’s best and brightest in human genetics and genomics research convene once a year for ASHG’s Annual Meeting, and you are invited! Join more than 8,000 scientists. Deletion and insertion mutations causing. Mutagens are designed for the specific biology of the character who concocted them, and your mutagens have no effect on other creatures. Introduction. Number of mutations identified in each variant’s spike, date of earliest documented sample. mutation. Some of these. To breed in Ark: Survival Ascended, you need to tame a female and a male dinosaur and enable the Mating option on the Behavior menu so they can reproduce and generate a baby dinosaur. Any environmental substance that causes a mutation is known as a mutagen, and these agents are called mutagenic agents. Targeted therapies. 9 Cystic Fibrosis. g. 2 7. In an organism when mutations create a change from wild type to abnormal phenotype, then that type of mutations are known as forward mutations. Beta hemoglobin (beta globin) is a single chain of 147 amino acids. Mutations In Grounded. Mutations to the gene that. Carcinogens What is the relationship between. 351Notable mutations: E484K, N501Y, K417N. Mutationer är förändringar i cellers genetiska material (oftast DNA, ibland RNA ). UV rays can damage the DNA in skin cells. Overall, about 88% of patients with pancreatic cancer have 1 of the RAS mutations. Mutagenesis. [1] Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. The main function of DNA polymerase is to synthesize a new DNA strand. It was fully implemented into version 2. Environmental mutagens as DNA damage activators enhancing carcinogenesis. F. 1A). Mutations are perks that players can obtain from completing certain challenges throughout the world. Point mutations involve the replacement of one base with another. The splicing process is performed in two steps. The prognostic value of a FLT3 mutation in the tyrosine kinase. Once activated, it phosphorylates targets that promote ATP-generating catabolic pathways or inhibit ATP-consuming anabolic pathways, helping to restore cellular energy. When a cell divides, the process of DNA replication is very carefully controlled to preserve the genetic information encoded within the nucleotide base sequence. The problem is that the only beneficial mutations ever observed do not add new information. Without mutation, evolution could not occur. Sometimes, during breeding, the genes of a cub get a little messed up! What comes afterwards can be a wild card. Some other examples of chemical mutagens include benzene (a major component of gasoline), vinyl chloride (common in pipes), and. Watch the next lesson: Abstract. This increases your risk for certain types of cancers, including: Colorectal cancer and polyps (growths of tissue) in your colon or rectum. 5: Results in a "stop" codon and premature termination of the protein. So in total, players can improve their defense. 7, and it spread quickly in South Africa to become the dominant. . Unlike germline mutations, which can be passed on to the descendants of an organism, somatic mutations. Somatic mutations are a normal part of aging and occur throughout an organism’s life cycle either spontaneously as a result of errors in DNA repair mechanisms or a direct response to stress. These include DNA reactive chemicals such as those listed below: Base Analogsmutagen, any agent capable of altering the genetic constitution of a cell by changing the structure of the hereditary material, deoxyribonucleic acid (DNA). E. The goal of precision medicine in prostate cancer (PCa) is to individualize the treatment according to the patient’s germline mutation status. Somatic mutation, genetic alteration acquired by a cell that can be passed to the progeny of the mutated cell in the course of cell division. 19 September 2023. This group of agents includes both natural and synthetic compounds. They are also unstable by nature, losing their potency over time and becoming inert if not used before you finish your next short or long rest. Aside from inheriting half of the genome of each of our parents, we are born with a small number of novel mutations that occurred during gametogenesis and postzygotically. Human epidermal growth factor receptor 2 (HER2), a receptor tyrosine kinase, is a major drug target and clinical biomarker in breast cancer treatment. g. Introduction. These bases are known as guanine, cytosine, adenine, and thymine. 1 14. Most of these changes are quickly repaired. Many alternative medicines interact with oral anticoagulants (principally warfarin) and interactions with plants are listed separately in Table 76. Other mutations can happen on their own during a person's life. The genes most commonly affected in hereditary breast and ovarian cancer are the breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes. v • r. The Figure is designed to assist practitioners to identify key mutations associated with resistance to antiretroviral. We often refer to a mutation as a thing—the genetic variation itself. Differences in your environment can expose you to different levels and types of mutagens. Elucidating the functional pathways altered by loss-of-function (LOF) or gain-of-function (GOF) mutations will be crucial for prioritizing cancer. Mutagens are agents that damage DNA and can, depending on the ability of an organism to repair the damage, lead to permanent changes (mutations) in the DNA sequence. Here the number of nucleotides that are added or removed from the coding. For example, if the codon GAA becomes the codon GAG, because the genetic code is degenerate, the codon will still code for the amino acid glutamate. 9. [1] Mutations in these cells are the only mutations that can be passed on to offspring, when either a mutated sperm or oocyte come. Mutational spectra produced by mutagens in various repair backgrounds can provide important information about the roles of different repair systems in the mutagenic. We review current knowledge on mutation rates and their harmful and beneficial effects on fitness and then. (Image credit: Muhammet Camdereli via Getty Images) Scientists have discovered that a key function from a "pure" branch of mathematics can predict how often. Carcinogens lead to. Figure 7. Paul Succop. Mutation trends from DRAGdb. 1e–g and Supplementary Table 2 ). Cells are the building blocks of your body. 5 ). As multiple isolates had been stored for some of. Overlap and Confusion. Kill Director Schmector. Mutations can also be the result of the addition of a nucleotide, known as an insertion, or the removal of a base, also known as deletion. In the Revised Cambridge Reference Sequence section, your results are displayed as follows: HVR1 Reference Sequence. These hereditary (or inherited) mutations are in almost every cell of the person's body throughout their life. 1 3. 7. Methergine is a type of medication used to stop uterine bleeding after childbirth. In the new study, the researchers we were able to determine the fraction of mutations due to random copying errors in 32 cancer types. -4. Names: 20H/501Y. The incidence and associated risk for cancer development by age 70 for BRCA1 and BRCA2 mutations are listed below [8] [9]. Unlike germline mutations, which can be passed on to the descendants of an organism, somatic mutations. That messenger RNA codon is then translated into an amino acid that goes on to make a protein that will be. MEN1M327V, MEN1M327I, MEN1G331R, MEN1G331D, MEN1T349M and MEN1S160C. Exposure to mutagens can occur through various routes, including ingestion, inhalation, and skin contact. For experiments with mutagens, the mutagenic chemicals were either added to the culture medium or used for seed imbibition or treatment of leaf pieces. Cancer-causing mutagens are known to be carcinogens, but not all mutants are necessarily carcinogenic in nature. Several of the identified metabolism-specific mutations are overrepresented in the genomes of >3500 clinical E. The estimated risk of ovarian cancer in women with a BRCA1 mutation is 39 to 46 percent by age 70. The resulting organism, called a mutant, may have a recognizable change in phenotype. The impacts of mosaicism on overall. Flagship has teamed up with four academic co-founders to launch Quotient. Abstract. Mutations occurring early in development can cause mosaicism within the gene line, impacting organism development. 1-3 AML is a hematopoietic stem cell (HSC) malignancy characterized by differentiation arrest and uncontrolled clonal. We analysed 41 137 MTBC isolates with phenotypic and whole-genome sequencing data from 45 countries. As of August 1, 2023, the University of Utah Department of Pathology and ARUP Laboratories no longer hosts this mutation database. Mutations have allowed humans to adapt to their environment. It may occur spontaneously in nature, or as a result of exposure to mutagens. cloudfront. A. This mutation rate is. If one thinks of the information in DNA as a series of sentences, mutations are errors in spelling the words that make up those sentences. Codons are a sequence of three nitrogen bases in a row that are "read" by messenger RNA during transcription. Here, I used the recent evolution of the bacterial enzyme TEM β-lactamase under antibiotic. Without the remainder of the amino acid chain, the protein may function. Insertion sequences (IS) are ubiquitous bacterial mobile genetic elements, and the mutations they cause can be deleterious, neutral, or beneficial. Somatic mutations are a normal part of aging and occur throughout an organism’s life cycle either spontaneously as a result of errors in DNA repair mechanisms or a direct response to stress. These errors in the viral RNA are called. DNA fails to copy accurately Most of the mutations that we think matter to evolution are “naturally-occurring. Duchenne is caused by mutations (changes) within the dystrophin gene. It discusses the molecular and cellular mechanisms, the diagnostic and prognostic implications, and the therapeutic options for patients with NPM1-mutated. Indeed, in our study, 208 participants (3. 18 × 10 −8 per position 2, which corresponds to ∼ 74 novel SNVs per genome per generation. Approximately 5-15% of PD patients have mutations in the GBA gene, making it numerically the most important genetic risk factor for Parkinson disease (PD). A gene linked. These mutations are more common in certain groups. For further insights see the External links section. 1. Mutations are random stat boosts and color changes applied to offspring when breeding tamed creatures. 005Identification of cathepsin C mutations in ethnically diverse Papillon-Lefèvre syndrome patients P S Hart, Y Zhang, E Firatli, C Uygur, M Lotfazar, M D Michalec, J J Marks, X Lu,Abstract. Very simply, a suppressor screen starts with a known mutation and then identifies second-site mutations that suppress the mutant phenotype. 1 Biol 3301: Genetics Exam #3 Practice questions 1. A mutation is a change in the DNA sequence of an organism. 1: Mutations and Mutagens. Since the DNA sequence found within. They have long been implicated in a range of genetically inherited afflictions, as well as cancer, aging and neurodegenerative diseases like Alzheimer’s. . MAP may also increase your. 5. It is estimated that one in eight women, or approximately 12%, will be diagnosed with breast cancer in her lifetime. a, Overview of direct detection and phenotyping of various TP53 coding mutations. As many mutations can cause cancer in animals, such mutagens can therefore be carcinogens, although not all necessarily are. Corporate Kickback. Cancer is a disease in which cells grow out of control and form abnormal masses of cells. Mutations may also occur during mitosis and meiosis. Mutations generate sequence diversity and provide a substrate for selection. Sickle cell gene therapy process may cause cancer-linked mutations in blood stem cells. They include the University of Texas Southwestern's Hao Zhu as well as Mike Stratton, Inigo Martincorena and Peter. 1016/j. Carcinogens, Mutagens, Teratogens and Reproductive Toxins Carcinogens Carcinogens are identified by their ability to cause cancer in exposed workers, other human populations, or in test animals. 10175. They are classified into physical, chemical and biological mutagens. Griffiths Professor Emeritus of Botany, University of British Columbia, Vancouver. Also Read: Mutagens. For example, UV radiation is a mutagen. If multiple mutations occur, they may affect the same or different stats. They are introduced to small-scale mutations (substitutions, deletions and insertions) and large-scale mutations (deletion duplications, inversions, insertions, translocations and nondisjunctions). Mutations are essential for evolution to occur because they increase ______. Technically, a mutation is defined as any. It can also be achieved experimentally using laboratory procedures. During this breakdown process, homocysteine can be recycled by our body to be reused to build other proteins. A nonsense mutation changes the codon for an amino acid into the codon for a “STOP” signal. net Björnstad syndrome is an autosomal recessive genetic disorder caused by a mutation in the BCS1L gene. Other Genetic ChangesIt is high. A mutation in the HERC2 gene acts as a switch that turns off the OCA2 gene, resulting in no brown pigment and blue eyes as a result. Mutations involve a random change in the natural functioning of chromosomes or their component genes; such changes rarely benefit the organism’s offspring. A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke. A mutation is a permanent and heritable change in genetic material, which. 1. With Mutated Skin, each adrenaline point decreases damage received by 15%. J. The game consists of challenges and tasks that are rewarding for you on a personal level, but in-game, you get perks; mutations are one of them. Learn more about the types of variants and how they affect gene function and health. Methods. 24, 2023-- Vertex Pharmaceuticals (Nasdaq:. 1. It causes base substitution or point mutation. Repeatedly kill creatures with a sword. Examples of harmful mutations. The international pictogram for chemicals that are sensitising, mutagenic, carcinogenic or toxic to reproduction. For example, bovine and human insulin, while differing in amino acid sequence are still able to perform the same function. Here is a quick summary of a few of these: Substitution A substitution is a mutation that exchanges one base for another (i. If new genetic information—required to build eyes where there are none, for example—does not occur in nature, then evolution is stuck in the water. Exonic sequences are numbered sequentially from the initiation codon to the stop codon. This designated area must be approved by the principal investigator. a permanent change in an…. c. For any questions or concerns related to the removal of this database from our website, please. Kathleen Dixon. 5 19. Glossary. Mutagens associated with cancers are often studied to learn about cancer and its prevention. Its application to somatic mutations of more. Conversely, anaplastic astrocytomas and glioblastomas with wild-type IDH1 and IDH2 genes had few TP53 mutations (18%) and more frequent alterations of PTEN, EGFR, CDKN2A, or CDKN2B (74%) (P<0. EGF plays an important role in the regulation of cell growth, proliferation and differentiation. Griffiths Fact-checked by The Editors of Encyclopaedia Britannica Mutagen, any agent capable of altering the genetic constitution of a cell by changing the structure of the hereditary material, deoxyribonucleic acid (DNA). Any agent causing mutation is called mutagen. Somatic mutations are DNA variants that occur after the fertilization of zygotes and accumulate during the developmental and aging processes in the human lifespan. By Jason Arunn Murugesu. Flagship has teamed up with four academic co-founders to launch Quotient. Carcinogens are mutagens that cause cancer such as UV radiation. It is a type of mutation where nucleotides are added/inserted into the DNA sequence. Small intestine (small bowel) cancer and polyps in your intestine. Mutagens are identified as genotoxic carcinogens. Endogenous mutagens, like reactive oxygen species (ROS), are produced by the body. Created by Ross Firestone. Four mutations are exposed when the spike tip swings open to grab human cells, and might help Omicron latch on tightly. The number of observed cases of pancreatic and prostate cancer was. One variant was inherited from each unaffected parent. Frequencies of mutations 1. The mutations are an important tool in understanding the relationship between two words and can differentiate various meanings. Clinically, GBA-associated PD is identical to. This change can affect a single nucleotide pair or larger gene segments of a chromosome. Using massively parallel DNA sequencing, we identified a somatic mutation in DNMT3A, encoding a DNA methyltransferase, in the genome of cells from a patient with AML with a normal. Irish, like Manx and colloquial Scottish Gaelic, uses two mutations on consonants: lenition ( Irish. Physical mutagens- These include UV light, Gamma rays, Cosmic rays, and X-rays. Mutagens are external factors that can cause alterations to DNA. Proofreading helps to maintain the integrity of the double-stranded DNA. Standard mutation nomenclature based on a “genomic DNA reference sequence” requires a prefix “g. Join the Amoeba Sisters as they explain gene and chromosome mutations, and explore the significance of these changes. For each offspring up to three mutations can occur, each with a 2. 13 Mutagens in Food As interest in the possible relationship between diet and cancer has increased in recent years, so have attempts to determine whether chemical carcinogens may be present in our foods. The pH-selective interaction between the immunoglobulin G (IgG) fragment crystallizable region (Fc region) and the neonatal Fc receptor (FcRn) is critical for prolonging the circulating half-lives. In our New World Mutation Guide, we’ll cover how to enter a mutation, the different mechanics you’ll face, the rewards you’ll get, and more! You MUST own the New World expansion, Rise of the Angry Earth,. 15 667 associations were computed for 13 211 unique mutations linked to one or more drugs. Chronic inflammation - DNA damage due to the production of mutagenic chemicals by the cells of the immune system; Oxygen radicals - Results from a cell's energy production and can damage DNA. However, women with certain genetic mutations have a higher lifetime risk of the disease. Prion mutations 00:00. But unfortunately, there's no treatment for 86% of them. If the F1 progeny are all wild-type, the mutations have successfully. The SARS-CoV-2 virus has mutated over time, resulting in genetic variation in the population of circulating viral strains, also called lineages. 2. It’s estimated that 55 – 65% of women with the BRCA1 mutation will develop breast cancer before age 70. Mutagens, either endogenous or exogenous, increase genetic mutation probability. 1149 (7·3%) of 15 667 mutations were classified. Human epidermal growth factor receptor 2 (HER2), a receptor tyrosine kinase, is a major drug target and clinical biomarker in breast cancer treatment. The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status activated by increases in AMP or ADP relative to ATP. Abstract. Viruses are simple entities, lacking an energy-generating system and having very limited biosynthetic capabilities. To compare the tumor mutation burden (TMB) between different groups, a. Anthony J. Here we conduct a study of genome-wide mutation rates by sequencing the entire genomes of 78 Icelandic parent-offspring trios at high coverage. Somatic mutation. Analysis was performed in 483 European patients and the seminal observations were validated in 396 Mayo Clinic patients. By contrast, 55% – 72% of women who inherit a harmful BRCA1 variant and 45% – 69% of women who inherit a harmful BRCA2 variant will develop breast cancer by 70–80 years of age ( 2 – 4 ). Antimutagenic agents are able to counteract the effects of mutagens. III. Definition. Tankyrases poly(ADP-ribosyl)ate and destabilize AXINs, β-catenin repressors. TP53, a crucial tumor suppressor gene, is the most commonly mutated gene in human cancers. Frame-shift mutations occur when a base is added or removed from the sequence. A systematic approach combining several of these signals could lead to a compendium of mutational cancer genes. *BRCA1 mutations have been linked to a very rare but aggressive type of cancer known as serous endometrial cancer. It may occur spontaneously in nature, or as a result of exposure to mutagens. Figure 4. Canonical mechanisms of antibiotic resistance are associated with drug target modification, transport, or enzymatic inactivation ( 1, 2 ). BRCA 1 Mutation. DNA polymerases IV/V (also called “DNA mutases”), which lack proofreading and will synthesize DNA to fill gaps when template is missing. F. Ultraviolet (UV) light induces specific mutations in the cellular and skin genome such as UV-signature and triplet mutations, the mechanism of which has been thought to involve translesion DNA synthesis (TLS) over UV-induced DNA base damage. Cancer-causing mutagens are known to be carcinogens, but not all mutants are necessarily carcinogenic in nature. Normally, the BRCA1 and. A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette. B. Mutagenic agents, which can threaten the integrity of the genetic code by causing mutations in DNA, pose a serious risk to human health. Viruses are subject to mutations, the genomes of different viruses can recombine to form novel progeny, the expression of. Apart from this, DNA polymerase is also involved in correcting the errors of added nucleotides in a process known as proofreading. Griffiths Professor Emeritus of Botany, University of British Columbia, Vancouver. . As traduções de minutagem a outras línguas apresentadas nesta seção foram obtidas através da tradução automática estatística; onde a unidade essencial da tradução é a palavra «minutagem» em português. Examples of potentially harmful environmental factors include toxic chemicals, X-rays and pollution. Key Points. Genes are made of deoxyribonucleic acid ( DNA ), a long molecule composed of building blocks called nucleotides. Mutations and New Genetic Information. Using single-cell.