genetics Definition and Topics - 67 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.

View More On
  1. 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...
  2. psean1991

    Is addiction really genetic?

    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...
  3. 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.
  4. 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...
  5. Navin

    Charging of tRNA

    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.
  6. 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...
  7. TranscedentKid

    Features of CRISPR-Gold?

    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...
  8. 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: «Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant» But if a...
  9. 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...
  10. N

    Benefits of variation?

    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...
  11. 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...
  12. 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...
  13. 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...
  14. 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...
  15. 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...
  16. 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...
  17. 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...
  18. 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...
  19. T

    Medical Down syndrome-role of mother

    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.
  20. 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.
  21. T

    What does "Genetic Code" mean?

    According to An Introduction to Genetic Analysis 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 not...
  22. 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.
  23. 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...
  24. Domenico94

    Two or three point test

    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 :)
  25. 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?
  26. B

    Eye heredity

    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?
  27. 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...
  28. P

    Why is red color dominant in 4o'clock plant?

    Mirabilis Jalapa exhibits incomplete dominance. So, if we cross Red and White colored plants (Parental Gen), we get, pink flowers (Filial I Gen). When these are selfed, we get red, pink, white in ratio 1:2:1 So, how do you determine that Red is dominant, because, we are dealing with incomplete...
  29. haael

    How can bacteria synthesize human insulin?

    I have just read that genetically modified e. coli can synthesize human insulin. But I wonder. Human (eucaryotic) genes have all kinds of introns, regulators, starting sequences etc. Bacteria don't have all of those. How can a procaryota produce an eucaryotic peptide? Has the insulin gene been...
  30. TrueGormagon

    Enhancing the Human body

    Greetings. Well I do not have enough time to pose all of my questions and ideas I can get this thread started off. So lets get right into it. The teeth of a Beaver incorporate a comparatively high percentage of iron in their construction, making them very strong and orange hued. (Also made to...