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Morgan's Experiment
Morgan was a geneticist .He was particularly interested how traits are inherited to offspring.He took a mutant male and bred with wild female.The resulting members of F1 generation all had red-eyes,but morgan suspected that white-eye trait is present in F1 generation,but remains unexpressed,like a recessive trait.He then crossed male and female of F1 generation and the get the resulting members of F2 with ratio 3:1 means one white eyed and three red eyed.
Morgan was curious that the why females never show white-eye trait,he predicted that white eye trait were lethal in females, he conducted a test cross of heterozygous F1 female and crossed with F2 male,and was surprised to see the ratio of 1:1:1:1 means red eyed ♀ ♂ and white eyed ♀ ♂,from this morgan comes to the conclusion:
The white eyed trait is expressed when F1♀ are bred with F2 ♂.
The appearance of the white eyed trait is not lethal in females.
Morgan's Test Crosses
* X+ = Red-eye trait (wild type)
* Xw = White-eye trait
In his first cross in which he wanted to explore relationship between eye color and sex.He crosses white eyed male with red eyed female,and the resulting generation had all red eyes as shown in fig(1).
Morgan's First Test Cross.
In his second test cross he bred a red eyed ♂ with red eyed ♀ from F1 generation and have resulting members of ratio 3:1 as shown in fig(2)
Morgan's Second Test Cross.
Morgan conducted the third cross to check that white eyed trait were lethal in females or not?He bred red eyed ♀ (X+ Xw) with white eyed ♂ (Xw Y) as shown in fig(3)
Morgan's Third Test Cross.
The third cross revealed that the white eyed trait were not lethal in females because it yielded a ratio of 1:1:1:1.
Finally,morgan conducted his fourth test cross to check wether the white eyed trait follow the inheritance of X-chromosomes from female gametes to male offspring.By this cross Morgan could predict that the white eyed female would be homozygous recessive.Because the male only inherit X-chromosome from the mother,so by crossing white eyed ♀(homozygous recessive) with red eyed ♂ shows that X-linked white eyed trait that male offspring carry from that Homozygous recessive mother.Thus, Morgan could predict that all ♂ offspring resulting from a cross between a white-eyed ♀ and a red-eyed ♂ would be white eyed.Likewise,because ♀ carry on X-chromosome from her father gametes,so all females from this cross(4rth) will carry red -eyed trait,and this trait dominate the recessive trait from female gametes.Morgan crossed a White eyed ♀with the red eyed ♂ as shown in fig(4)
Morgan's Fourth Test Cross.
This cross yielded all white-eyed ♂ and all red-eyed ♀ , Morgan could indeed conclude that the white-eye trait followed a sex-linked pattern of inheritance.
CONCLUSION:
From this experiment it is concluded that the Mutant white eyed father passes the trait to his daughter and the daughter passes the white eyed trait to her son and so-on.For this theory Morgan was awarded noble prize in 1933,
BIOLOGY:
Biology is a natural science, the study of living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy.
ORIGIN:
The term biology is derived from the Greek word, bios, "life"-logia, "study of." and may be a back-formation from the older word amphibiology (meaning the study of amphibians) by deletion of the initial amphi-.
BRANCHES OF BIOLOGY:
Aerobiology — the study of airborne organic particles
Agriculture — the study of producing crops from the land, with an emphasis on practical applications
Anatomy — the study of form and function, in plants, animals, and other organisms, or specifically in humans
Arachnology — the study of arachnids
Astrobiology — the study of evolution, distribution, and future of life in the universe—also known as exobiology, exopaleontology, and bioastronomy
Biochemistry — the study of the chemical reactions required for life to exist and function, usually a focus on the cellular level
Bioengineering — the study of biology through the means of engineering with an emphasis on applied knowledge and especially related to biotechnology
Biogeography — the study of the distribution of species spatially and temporally
Bioinformatics — the use of information technology for the study, collection, and storage of genomic and other biological data
Biomathematics or Mathematical Biology — the quantitative or mathematical study of biological processes, with an emphasis on modeling
Biomechanics — often considered a branch of medicine, the study of the mechanics of living beings, with an emphasis on applied use through prosthetics or orthotics
Biomedical research — the study of the human body in health and disease
Biophysics — the study of biological processes through physics, by applying the theories and methods traditionally used in the physical sciences
Biotechnology — a new and sometimes controversial branch of biology that studies the manipulation of living matter, including genetic modification and synthetic biology
Building biology — the study of the indoor living environment
Botany — the study of plants
Cell biology — the study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell
Conservation Biology — the study of the preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife
Cryobiology — the study of the effects of lower than normally preferred temperatures on living beings.
Developmental biology — the study of the processes through which an organism forms, from zygote to full structure
Ecology — the study of the interactions of living organisms with one another and with the non-living elements of their environment
Embryology — the study of the development of embryo (from fecundation to birth).
Entomology — the study of insects
Environmental Biology — the study of the natural world, as a whole or in a particular area, especially as affected by human activity
Epidemiology — a major component of public health research, studying factors affecting the health of populations
Ethology — the study of animal behavior
Evolutionary Biology — the study of the origin and descent of species over time
Genetics — the study of genes and heredity
Herpetology — the study of reptiles and amphibians
Histology — the study of cells and tissues, a microscopic branch of anatomy
Ichthyology — the study of fish
Integrative biology — the study of whole organisms
Limnology — the study of inland waters
Mammalogy — the study of mammals
Marine Biology — the study of ocean ecosystems, plants, animals, and other living beings
Microbiology — the study of microscopic organisms (microorganisms) and their interactions with other living things
Molecular Biology — the study of biology and biological functions at the molecular level, some cross over with biochemistry
Mycology — the study of fungi
Neurobiology — the study of the nervous system, including anatomy, physiology and pathology
Oceanography — the study of the ocean, including ocean life, environment, geography, weather, and other aspects influencing the ocean
Oncology — the study of cancer processes, including virus or mutation oncogenesis, angiogenesis and tissues remoldings
Ornithology — the study of birds
Population biology — the study of groups of conspecific organisms,
Paleontology — the study of fossils and sometimes geographic evidence of prehistoric life
Pathobiology or pathology — the study of diseases, and the causes, processes, nature, and development of disease
Parasitology — the study of parasites and parasitism
Pharmacology — the study and practical application of preparation, use, and effects of drugs and synthetic medicines
Physiology — the study of the functioning of living organisms and the organs and parts of living organisms
Phytopathology — the study of plant diseases (also called Plant Pathology)
Psychobiology — the study of the biological bases of psychology
Sociobiology — the study of the biological bases of sociology
Structural biology — a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules
Virology — the study of viruses and some other virus-like agents
Zoology — the study of animals, including classification, physiology, development, and behavior.
BIOLOGICAL SCIENCES:
The best biological sciences are studied in Germany,as the cell theory which is the foundation of biology was proposed by two German scientists named Theodor Schwann(zoologist) and Matthias Jakob Schleiden(botanist).
FATHER OF BIOLOGY:
Aristotle is considered to be the father of biology because he has given a lot of idea regarding life, distinguished between plant and animal,specify what is life and in which way a life is functioning out.
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