What is Genetics: Definition and 196 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. T

    Biology Genetics Questions: Breeding for Orange Tail and Long Beak Birds

    I am not sure how to go about solving this: Homework Statement A true breeding bird species shows yellow tail feathers in the adults (determined by the y+ allele at tail feather locus) and long beaks (b+ allele at beak length locus). On a Pacific Island, a new strain is discovered that...
  2. T

    Biology Genetic Inheritance in Moths: Miniature and Spotting Alleles Distribution

    I am not sure about how to solve this one: In a particular species of moths, the miniature gene is located on the Z chromosome; two alleles are known: the recessive allele m causes homozygotes to have a small wing phenotype, whereas the dominant allele M confers a normal wing size to the...
  3. S

    Biology Can anyone help me with ny of these 4 genetics questions?

    1. The genes for mohogany eyes and ebony body are approximately 25 map units apart on chromosome III in Drosophila. Assume that a mahogany-eyed female was mated to an ebony-bodied male and the resulting F1 phenotypically wild type females were mated to mahogany, ebony males. Of 1000 offspring...
  4. F

    Biology Mendelian Genetics: Probability of Inheriting Codominant Traits

    Homework Statement Assuming that there is a 1/32 chance that a child will show a certain trait, and we need to calculate the probability that 2 parents will have 4 children with this specific trait, do we do the following: Homework Equations (1/32)^4 The Attempt at a Solution 1/32768...
  5. Astronuc

    Medical Genetics - a link between maths and autism

    Professor Simon Baron-Cohen is doing an interesting study of the links between autism and the ability to do math or systemise. http://www.timesonline.co.uk/tol/life_and_style/health/article2060584.ece Autism: the truth
  6. S

    DNA study challenges basic ideas in genetics Genome 'junk' appears essential

    This is what any involved person intuitivelly knew from the beginning of the hype, and now even the scientists figured out: :confused: http://www.boston.com/news/science/articles/2007/06/14/dna_study_challenges_basic_ideas_in_genetics/"
  7. I

    Biology Autosomal and X-linked genetics problem

    Homework Statement In the fruit fly drosophila melanogaster, vestigial (partially formed) wings (vg) are recessive to normal long wings (vg+) and the gene for this trait is autosomal. The gene for the white eye trait (w = white is recessive to w+ = red) is located on the X chromosome. Suppose...
  8. I

    Biology Genetics/ Probability Problems

    Hi, I'm just stuck on a few questions. Can anyone offer me some assistance? a) In families with four children, what proportion of the families will have at least one boy? b) In families with two girls and one boy, what fraction of the families will have the boy as the second child...
  9. B

    Hidden Variable: The Role of Genetics and Parents in Twins

    Tell me if the analogy holds: Twins are generated by black eye fathers and green eyed mothers Let it be the "green eye" or the "black eye" our observable variable. Only identical twins are chosen. The twins A and B are sealed, each one, in a closed box, we have to predict the...
  10. T

    Biology [Help] Simple Genetics Questions

    1. Answer the following questions as they relate to a human cell undergoing meosis. a) how many gametes will result from each meiosis in a human male and from each meiosis in a human female? I think it's one gamete each? I'm not sure how to interpret this question b) how many...
  11. V

    Uncovering the Influence of Genetics on Favorite Color Choices in Humans

    What determines why we say a certain colour is our favourite colour? And do favourite colour choices run in families?
  12. N

    Pop. Books on Evolution and Genetics

    Probably on the list of top 5 interesting (science) topics, of which I know next to nothing. Okay, natural selection, survival of the fittest and all that, but I'd like to have a better understanding, at least at the level of a layman. My last biology class was in school, about 7 years ago...
  13. B

    Ever Wondered What Goes on Inside a Student Genetics Lab?

    Here is a cool tour inside of a Genetics Lab. Make sure to check out the zebra fish mutants and the mouse guillotine! :eek:
  14. R

    Biology Genetics of Colour Blindness: A Familial Inheritance Question

    ok i have this question for homework, can anyone help me? A man's maternal grandmother had normal vision; his maternal grandfather was colour-blind;his mother is colour-blined;his father has normal vision. Calculate the genotypes of the two parents and grandparents mentioned? What type of...
  15. Loren Booda

    Influences beside genetics and environment

    What influences the development of an organism, or organisms in general, other than genetics and environment? E. g., would ontogeny, cell structure, psychology or hormones qualify?
  16. M

    Biology Solving Genetics Problems: 5 Mutant Males x 5 Wild Type Females

    Hi Everyone, I have been trying to solve these problems with no success. Please help. Thanks in advance. 1. Determine the nature of the traits being studied (ie. whether linked or sex-linked). Explain how you reached the conclusion. Attempted Answer: The cross was between 5 mutant...
  17. V

    Evolution & Genetics: Human-Chimp-Fly Comparisons

    Something I read promoting intelligent design states that science is disproving the connection between chimps and people. Now I read a science article on the matter and it states that the base pairs compare and there is about 1 or 2 % difference, but of the actual genes they are as much as 80%...
  18. E

    A good introduction to Genetics

    I'm going to study genetics in college next year, and I was hoping I could get a head start. I have looked at many books such as the Cartoon Guide to Genetics, Schaum's Outline Of Genetics, Genetics for Dummies, etc. But I was afriad of some of these books being either too advanced or too...
  19. G

    Junior at molecular biology and genetics

    I am a junior at molecular biology and genetics and I plan to apply for grad school next year. So I need to take GRE general and subject tests, plus TOEFL. My main concern is about GRE: when should I start preparing for it? I would really appreciate advices also on how to study. Thanks! Gamze
  20. J

    Biology Solving Genetics Problem: Y-Linked Recessive Trait Inheritance

    My Question: What is the mechanism of inheritance for the trait? Which people in the pedigree are known to be heterozygous for the trait? What is the probability that III-2 is a carrier( heterozygous)? If III-3 and III-4 marry, what is the probability that their first child will have the...
  21. B

    Exploring Genetics: Why Am I Short?

    I'm not very knowledged in genetics, although I'm interested in the subject, and was hoping someone could give me some insight into any possible reasons for why I'm short. I'm a caucasian male and I'm only around 5'7". I know I take after my father who is also around my height, but I don't...
  22. A

    Advice on Genetics Study for A-Level Student

    I really want to study genetics, but I'm not too sure how to go about it. My dad is advising me to get a degree in medice first, but shouldn't i just study genetics as my first degree? Please give me some advice about what to do. I am at my final year at secondary school(high school) and I'm...
  23. T

    Individual or group wanted to help the study of genetics

    If an individual or group wanted to help the study of genetics (in general) progress faster (because they wanted it to) how could they do that? Through fund-raising and stuff? Or could they not really do that at all?
  24. A

    A question about Adam & Eve concerning genetics.

    I am not good at biology and genetics so I need your help about something I've read. In the article it is said that using the genetic code information and the mithocondrial DNA, which i specific for females and males, it is concluded that the first female (EVE) has lived 143.000 years ago in...
  25. D

    I wanted to talk to an expert on genetics/human genetics

    Hi I'm doing a project for school and I wanted to talk to an expert on genetics/human genetics. Could somebody tell me what the best expert to talk to would be? I emailed some ppl but got out of office replies and I don't really know who would be the best expert to talk to or how to find out...
  26. K

    What Are the Possible Genotypes of the Bull and Cows in This Monohybrid Cross?

    Chickens with shortened wings and legs are called creepers, when creepers are mated to normal birds, they produce half creepers and half normal birds. When creepers aremated to creepers they produce 2 creepers to 1 normal. Crosses between normal birds produce only normal offspring. How must...
  27. M

    Studying Making a Career in Genetics: How to Get Started

    Hey guys, My little brother who is in high school is obsessed with genetics, and he wants to go into this field after graduating from high school this year. Does anyone know what's the best way to make a career out of genetics in the US? I am a physics major and I don't know much about...
  28. S

    Questions on genetics: gene co-ordinate systems and gene interpretations

    I am curious to know how cells in developing organisms can know which direction to grow in, how much tissue is required and in what proportion, and how to differentiate to the right cells. If we just take the first issue, which is directional growth, I remember from my O-level biology classes...
  29. C

    Genetics Basics: A Beginner's Guide to Genetics

    Hi everyone, I'm new to genetics, but would like to start studying it, what would be a good starting book :confused:
  30. O

    Book wanted: Overview of Genetics

    I am looking for a fairly comprehensive, well written overview of cell functions, DNA, Genes, Protiens, bacterium, viruses (virii?), reproduction, gestation, etc... One that covers genetics and life from an easy to read and sensible perspective for people who are not University-Schooled...
  31. D

    Genetics Project Ideas for Grade 11 Biology

    Hi all, I am a grade 11 biology student. I have this genetics project coming up in a few weeks, and I am allowed to research on anything I would like. Could you please help me and try to come up with some really good topics for my project? Thanks. (btw, someone else in my class is already...
  32. S

    Genetics Desperately waiting for replies

    Genetics!Desperately waiting for replies In drosophilia,blackbody colour is recessive to grey body colour.A geneticist had 3 pairs of flies with grey body designated A,B and C.He crossed A and b and obtained 109 grey bodied flies,A and C gave 80 grey bodied and 28 black bodied whilst B and...
  33. D

    Genetics: Uncovering the Genotype of Black Mouse with Tan Parent

    In mice, the gene C causes pigment to be produced, while the recessive gene c makes it impossible to produce pigment (albino). Another gene, B, on a different chromosome, causes a chemical reaction with the pigment and produces a black coat colour. The recessive gene, b, causes an incomplete...
  34. D

    Genetics: Is Insect Resistance Trait Dominant or Recessive?

    You have genetically engineered a tomato plant to be resistant to an insect pest by introducing a gene into tomato seeds that codes for a protein that is poison to the insect, but harmless to humans. After several generations you have obtained a true-breeding line of insect resistant tomatoes...
  35. D

    Genetics: transcription translation help

    OK i just want some clarification on what i am doing is right if it is wrong please help me first i have a template strand for a part of a DNA this is TAC CGA TGA CCA TCA GCC TGC now this strand is decoded via the process of transcription into mRNA where it moves to the cytoplasm...
  36. I

    Are Fingerprints a Result of Genetic Code or Environment?

    Identical twins have identical genetic codes. [Some if not all]* Identical twins also have different finger prints. This induces me to wonder if finger prints are a result of the genetic code or not. If the genetic codes of identical twins are identical, then, if finger prints are manifested...
  37. A

    Reading Material for Neuroscience, Genetics, Biochem

    I have a working knowledge of Neuroscience, but I disire to learn more, also id like to start gather knowledge on Genetics and Biochem... if someone can please suggest good informational reading material on Neuroscience, or an Introduction to Genetics/Biochem. that would be very helpfull. Thanks...
  38. A

    Nuroscience and a little in genetics

    Hello, I am new to the boards. Just wanted to get aquainted with eveyone and say hello. My real scientific strength lies in nuroscience and a little in genetics. It is here i am most intregued and extreamly eager to devour any and all information. Hope to see you all around. =)
  39. P

    Help with a VERY HARD genetics question PLEASE?

    I'm a first-year college student and I'm havnig a lot of trouble with a particular question. Here goes: Manx cats are tailess and when crossed with one another produceo n averaeg one long-tailed cat for every 2 Manx. The allele is lethal in homozygous condition due to problems arisiging in...
  40. R

    Exploring Cancer: Genetics, Cell Division & Treatment

    Just seen an interesting documentary about the breakthrough in Cancer treatments. The programme gives a brief discription on cell division and how doctors think the way forward for treatment is changing due to the Understanding of Genetic (genome) discovery. Anyway I was fascinated by the film...
  41. Jeebus

    Twins & Fingerprints: Development or Genetics?

    Are fingerprints the same for twins? That is, are they based on development, on the genetic code, or a combination of both? Its probably a dumb question, but it had me wondering.
  42. R

    Is the Delta Symbol Relevant in Genotype Terminology?

    Sadly enough, I have never seen a delta symbol in front of a printed genotype. Does this mean anymore than the obvious (obvious being some given changed, unstated, to the genotype)?
  43. E

    Is homosexuality is the result of genetics

    If homosexuality is the result of genetics gone wrong then how come their is no other gay animals in the world?
  44. heusdens

    Space Genetics: A Weird Physics Theory on Mass, Radiation, and the Universe

    Here is a link to weird physics theory, called "Space genetics" by some russian physiscts (Dr. Dark Energy), who has a theory in which mass "consumes" space, and radiation by stars "creates" back the space consumed by mass...creating in fact a universe in perfect equilibrium of finite size but...
  45. M

    Solve Genetics Q by John Meninger | No Genetics Knowledge Req'd

    I am currently enrolled in molecular genetics taught by John Meninger (Harvard graduate) who has worked with scientists such as Messelson, Holliday, and such. This is one of his questions which I thought was a bit confusing at first. He seems to think that the question makes perfect sense. It...
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