What is Genetics: Definition and 198 Discussions

Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms.Though heredity had been observed for millennia, Gregor Mendel, Moravian scientist and Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene.
Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded beyond inheritance to studying the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the context of a population. Genetics has given rise to a number of subfields, including molecular genetics, epigenetics and population genetics. Organisms studied within the broad field span the domains of life (archaea, bacteria, and eukarya).
Genetic processes work in combination with an organism's environment and experiences to influence development and behavior, often referred to as nature versus nurture. The intracellular or extracellular environment of a living cell or organism may switch gene transcription on or off. A classic example is two seeds of genetically identical corn, one placed in a temperate climate and one in an arid climate (lacking sufficient waterfall or rain). While the average height of the two corn stalks may be genetically determined to be equal, the one in the arid climate only grows to half the height of the one in the temperate climate due to lack of water and nutrients in its environment.

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  1. H

    A DNA Animation

    Nicely done. Supercomputer? They say the animation is real time but wouldn't the real thing be much quicker?
  2. H

    Looking For Today's DNA Knowledge

    I got my biology degree in 1979 and would like to get current again on DNA. What would you suggest? I'm in Japan so access to English books is quite limited.
  3. H

    Biology Honors Project thought

    Hello, I am a community college student currently in cellular and molecular biology. I wanted to do an honors project for this class and I was hoping I could get some thoughts or suggestions on this idea. My project idea is this; I want to help make anti venom through a new and creative way. I...
  4. S

    Biology A male has black hair and a woman has white hair. What is the expected hair color of the offspring if both alleles are dominant?

    If we draw a punnet square, it would look like this Male on horizontal Female on vertical Cb Cb Cw CbCw CbCw Cw CbCw CbCw Does this mean that the offspring will have a blend of both black & white hair i.e. grey? Or is there something that is being missed here?
  5. S

    Biology Huntington Disease Pedigree Problem

    The first picture is the image given in the question, and the second picture is the possible genotypes given in the solution manual. How is it possible that person II.1 (first male in the second generation) has the genotype A/- when he is unaffected? I thought that because person II.1 and...
  6. BillTre

    Lingusitics Great Human Genetics, Language and Culture Podcast

    I just listened to a great podcast on the explosion of human genomic data about human migration, which ties in with the spread of ancient language groups, and reveals some of past cultural practices. It is Sean Carroll's Mindscape podcast #179; David Reich on genetics and ancient humanity...
  7. nomadreid

    2 questions: illusory "force" between hands, and "wave genetics"

    The first question concerns reports by people who claim that there is a "force" pulling or pushing their hands when they hold their hands in front of them, close to each other, and parallel to one another, or while slowly moving their hands apart. Obviously there are no significant forces...
  8. TytoAlba95

    Biology MCQ: Genetics- Recombination in Drosophila

    Here (A) is a product of recombination between a-&-b, (B) is a product of recombination between b-&-c and (C) a parent 1. If 1000 is the total number of progenies, then 10% of it is 100 (A), 5% is 50 (B) and the rest should be <850 because the other parent has not been included. So I reject 1...
  9. T

    Questions about DNA, biology, genetics and genealogy tests

    Is there any DNA, biology, genetics and genealogy tests that i can take to find out what i am supposed to do naturally OR what I am naturally made for? for example, my sexuality or being straight, bisexual, gay. If yes, what do these tests tell me about my DNA, biology and/or genes? Even if its...
  10. P

    Biology Genetics Probability (Autosomal Recessive)

    I think both Jane and Bill are carriers. I'm unsure if the answer is 1/4 (25%).
  11. TytoAlba95

    Biology Genetics: Calculating probability

    My Attempt: For the child to be affected, both the parents must be carriers. Hence P(child)= Probability of the father of passing down an affected allele x Probability of the mother of passing down an affected allele = 1/2 x 1/2 =1/4 The...
  12. TytoAlba95

    Biology Genetics: What is the probability that the third child will be affected

    pg-363, sum-334 Attempt: The disorder is autosomal recessive. The probability = Probability of being a daughter x Probability of an affected child being born = ½×¼ = 1/8 x100 =12.5%
  13. TytoAlba95

    Biology Genetics problem-Interrupted mating

    My Attempt: It appears to me that the three Hfr strains are derived from the same F+ bacteria. This info is absent in the question. Now on aligning all three sets of genes, the first and second set doesn't match completely. I do not understand why it doesn't as they are supposed to be...
  14. TytoAlba95

    Biology Genetics Problem -- Colourblindness is a recessive X linked trait

    I'm getting 3/32. P= Probability of a daughter x Probability of O blood type x Probability of Normal vision = 1/2 x 1/4 x 3/4 = 3/32
  15. psean1991

    Is the Link Between Genetics and Addiction a Flawed Belief?

    My brother has been in and out of rehabs for years, and lately I've been researching addiction and trying to understand the science behind it. A lot of sites that I've found say that addiction is genetic, but the info is extremely generalized and surface level. I haven't found any specific...
  16. Beth N

    Biology Genetics: Mutation and Complementation

    Homework Statement Question 2[/B] You mutagenize male flies with EMS. Next you mate an EMS-treated male fly to a wild-type female fly. (i) If you find an F1 offspring with a sleep-too-little mutant phenotype, what does that suggest to you about this mutation? (ii) You expect that majority of...
  17. TytoAlba95

    Silent mutation and third position

    I got this question in an exam. Why do silent mutations always affect the third position of a codon? I have no clue about it.
  18. K

    What is the weight of genetics in preventing disease

    Is there any research or study which is to estimate the weight of genetics in preventing one or more diseases compared to other factors? A lot of time, for example, explaining how a particular kind of cancer occurs in someone, genetics is often mentioned, in addition to other factors, but how...
  19. Ashley1999

    Programs Should I switch my major to Molecular Genetics?

    Hi, currently I am a freshman who is majoring in Biosystems Engineering. I selected this major because I did a lot of research into biology undergrads and I didn't like what I saw. I got the notion that these majors did not emphasize the technical skills necessary to do well in a science...
  20. Wrichik Basu

    Gene for allergies and the common cold

    Some people are more susceptible to allergies and common cold than others. For example, my mother and I suffer from dust allergies and blocked nostrils throughout the year. In fact, last year or so, my mother had to be hospitalised as her lungs had become stiff due to sudden allergy. Almost...
  21. Navin

    Charging tRNA for Dummies: Amino Acid Attachment & CCA Explained

    Hi could some one please explain Charging of tRNA (for dummies) ? Like i wanted info of the enzume complex during amino acid attachement and how the acceptor arm and CCA accepts the amino acid.
  22. TytoAlba95

    Biology What Are the Parental Genotypes of Fruitflies with Mixed Phenotypes?

    Homework Statement A wild type fruitfly was crossed with another fruitfly whose phenotype was not recorded. They had progenies in the following ratios. 3/8 wild type, 3/8 ebony body, 1/8 vestigial wings and 1/8 ebony body and vestigial wing. If the genes are located on different chromosomes and...
  23. TytoAlba95

    Biology Genetics Problem -- six independently assorting genes in a plant

    Homework Statement A researcher studied six independently assorting genes in a plant. Each gene has a dominant and a recessive allele: R black stem, r red stem; D tall plant, d dwarf plant; C full pods, c constricted pods; O round fruit, o oval fruit; H hairless leaves, h hairy leaves; W purple...
  24. TranscedentKid

    What Makes CRISPR-Gold a Promising Tool for Genetic Diseases?

    Why is gold un-reactive enough to be used as nanoparticles? Why do cells preform endocytosis upon detection of the gold delivery system? What are the chemical receptors active? Why is does it cause less genetic damage than doing it virally? Is this system partly designed to change the DNA of...
  25. S

    Biology Genetics: Understanding the Base Sequence of Messenger RNA

    Homework Statement [/B] I am reviewing an example on the basics of the genetic code; this example is listed at the bottom of the following webpage: https://www.atdbio.com/content/14/Transcription-Translation-and-Replication.I have produced the example below and added Roman numbers to better...
  26. guidoeg

    Medical Xray diagnostics mutagenic and so genocide effect on genome

    They worry only about X-rays risks during pregnancy but not in pre-gravid wonen on pre-zygote oöcytes: https://www.radiologyinfo.org/en/info.cfm?pg=abdominct «Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant» But if a...
  27. navneet9431

    Is light eye colour dominant or recessive trait?

    Homework Statement A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not? Homework Equations Not Any The Attempt at a Solution...
  28. P

    How does genetics account for behavioral variations

    I am referring to the behavioral variation of dog puppies in a litter. Some may be sissies, non combative golden retriever-ish, while others were born tough as nails. This is just as true for rottweilers as Golden Retrievers. Given that they are all raised together, thus living in the same...
  29. N

    Is Variation During Reproduction Beneficial for the Individual?

    Homework Statement Variation during reproduction is beneficial to the species but not necessarily for the individual? Homework Equations Not any The Attempt at a Solution I only know about variation during reproduction is beneficial to the species but I don't know anything about how it is not...
  30. David23454

    Biology Genetics Chromosomal Inversion problem

    Homework Statement Rewrite following sequence as double stranded molecule, with an inversion of the sequence between nucleotide 4 and 12. 5'-TCTCGCATGGTAGGT-3' Homework Equations none. The Attempt at a Solution [/B] I've read in the textbook that you take the section and rotate it 180...
  31. D

    Genetics double recombination counted twice in terms of RF

    When mapping out re-combinations of a crossed trihybrid you have to account for the proportion of the offspring who do not share parental genotypes. Of the 8 possible genotypes stemming from this mating, 6 will be recombinant and two will be of parental genotypes. Your idea is to Map out the...
  32. Ygggdrasil

    Omnigenetic model for complex traits

    Related to the recent discussions on this forum about the potential for genetically engineering humans in the future, researchers from Stanford University recently published a fascinating article in the journal Cell, looking into the genetics of complex traits, like height, as well as the...
  33. D

    Genetics, replication of heterozygous diploids – conceptual

    So you have two alleles for every one gene, and the chromosome is composed of 2 homologous chromatids that have one of the 2 alleles for the specified gene on each chromatid. when you have to replicate that chromosome the way I understand DNA replication is is that you have a serious of...
  34. Tukhara

    Do you see Anthropology as a serious science?

    I have become invested in Anthropology since the second half of 2016. Now while I say I find Anthropology not serious, I exclude the genetic side of things since that is of course real. Also the historical and archaeological basis behind it. What I am referring to is the racial/physical side of...
  35. T

    MCQ - Independent assortment or Incomplete linkage

    Homework Statement Two flies were crossed one wildtype another double mutant sepia(se) and vestigial(vg) yielding 40% wild type 40% se vg, 10% se and 10% vg. The genes show- a.Complete linkage b.Incomplete linkage c.Independent assortment d. epistasis 2. The attempt at a solution Since no. of...
  36. T

    What is linkage strength between gene loci?

    Homework Statement In linkage strength between any two gene loci is 70%,what would be the amount of crossing over between these loci? (a) 15% (b)30% (c) 70% (d) none of these. 2. My approach at understanding the concept I didn't find much about linkage strength from any authentic source. I...
  37. L

    Does My Height Make Sense for My Genetic Makeup?

    Me: 6'0.125" Elder brother: 6'2.7" Sister: 5'9.25" Father: About as tall as my brother Grandfather (paternal side): I don't know his height due to him having passed away long before I was born, but he looked about as tall me in a picture Mother: 5'4.5" Grandmother (maternal side): Used to be...
  38. T

    What are housekeeping and constitutive genes?

    I have come across two set of definitions which are not contradictory but different. From wikipedia: A constitutive gene is a gene that is transcribed continually as opposed to a facultative gene, which is only transcribed when needed. A housekeeping gene is typically a constitutive gene...
  39. T

    Variant of a syndrome vs Syndrome

    Individuals with 48, XXXY or 49,XXXXY are called variants of Klinefelter Syndrome by P.J.Russell,2010 (i Genetics). But I read a paper published in 2011 titled: 48,XXYY, 48,XXXY and 49,XXXXY syndromes: not just variants of Klinefelter syndrome. My question is why the physiological condition...
  40. T

    Medical Molecular Mechanisms Behind Maternal Age and Down Syndrome Risk

    Why does increase in age of the mother increases the chance of having an offspring with Down Syndrome? I want to know the molecular basis of this observation. I'll be grateful if somebody could recommend an authentic source in this regard.
  41. T

    How do I define haploid and monoploid?

    I think I understand these terms, not fully though and I can't distinguish between the two and define them.
  42. T

    What does "Genetic Code" mean?

    According to https://www.ncbi.nlm.nih.gov/books/NBK21950/ and some other sources: 'Genetic code is the set of correspondences between nucleotide pair triplets in DNA and amino acids in protein.' What dose correspondences mean in this regard? I don't understand why nucleotide pair triplets and...
  43. klotza

    Insights Polymer Physics and Genetic Sequencing - Comments

    klotza submitted a new PF Insights post Polymer Physics and Genetic Sequencing Continue reading the Original PF Insights Post.
  44. C

    Other Book recommendations read for genetics, evolution, and neurobiology

    Hello everyone, So I'm a CS major college student. I've always been interested in biology, especially evolution and genetics; but recently I've been really interested in neurobiology. I read a lot from all kind of stuff and I thought I could read some books on these subjects. What I'm looking...
  45. L

    Possible # alleles at locus of 3 base-pairs (diploid)?

    How many possible alleles are at a locus consisting of 3 base-pairs in a diploid? ugh, I am so confused... So, I guess a locus is just a spot for a gene, so the gene is also considered to consist of 3 bases. Gene: _ _ _ Each "_" could be either an A,T,C, or G. So there are 4 possibilities...
  46. Domenico94

    Understanding Genetic Inheritance: A Two or Three Point Test Example

    Hi everyone. Can someone please explain me how a two or three points test can be made, in the field of genetics? I've read of it in many books, but I'm looking for an explanation as clear as possible. Thanks in advance :)
  47. L

    What is a current case study about the cri du chat syndrome?

    Examples of recent studies and tests on this genetic disorder, preferably done in Canada?
  48. CMATT

    Biology How to Calculate Heritability in Fruit Fly Bristle Number Genetics

    Homework Statement A geneticist studying the number of bristles on the second leg of fruit flies determined that a wild-type strain has a mean number of 486.3 bristles per leg. A sample of males and females from this population with 420.0 bristles were bred and the offspring had a mean bristle...
  49. B

    The Mystery of the Couple's Children: Eye Color Edition

    Hello, In the picture above a couple are shown with their children. Or are they actually their children? Is it possible for them, having green (?) and hazel (?) eyes, to get 1 child with blue eyes and 3 children with brown eyes?
  50. RoundEarVulcan

    Bioinformatics and observing genetic mutations

    Hi, For starters, I am an Electrical Engineering student and have very little formal training in the field of Biology. Also, I am not sure if this question is more suited for the Bio or CS section of the forum. My questions are: - How is Bioinformatics used to observe genetic mutations...