Post on 15-Jul-2015
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A gene is the molecular unit of heredity of a living organismThe word gene is derived from the Greek word genesis meaning "birth", or genos meaning "origin"
Deoxyribonucleic acid (DNA) is a molecule that encodes the
genetic instructions used in the development and functioning of all
known living organisms and many viruses
DNA is a nucleic
acid; alongside
proteins and
carbohydrates,
nucleic acids
compose the three
major
macromolecules
essential for all
known forms of life.
Ribonucleic acid (RNA) is a polymeric molecule. It is implicated in a varied sort of biological roles in coding, decoding, regulation, and expression of genes
Genes hold the
information to
build and
maintain an
organism's cells
and pass
genetic traits to
offspring
What do the genes do?
All organisms have genes corresponding to various biological traits, some of which are instantly visible, such as eye color or number of limbs, and some of which are not, such as blood type, increased risk for specific diseases, or the thousands of basic biochemical processes that comprise life.
The existence of genes was first implied from the work of Gregor Mendel (1822–1884), who, between the years of 1857 to 1864 planted 8000 common edible pea plants and studied and tabulated the inheritance patterns in pea plants (Pisum) tracking inheritance of traits from parent to offspring and describing these mathematically as 2n combinations where n is the number of differing characteristics in the original peas.
Heredity is the
passing of
phenotypic traits
from parents to their
offspring, either
through asexual
reproduction or
sexual reproduction.
Reproduction (or procreation) is the biological process by which new individual organisms –"offspring" – are produced from their "parents". Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction.
Asexual reproduction is a mode of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it is reproduction which almost never involves ploidy or reduction.
Sexual reproduction is a biological process that creates a new organism by combining the genetic material of two organisms in a process that starts with meiosis, a specialized type of cell division. Sexual reproduction is the primary method of reproduction for the vast majority of macroscopic organisms, including almost all animals and plants
Explain heredity?
Heredity is the passing of phenotypic traits from parents to their offspring, either through asexual reproduction or sexual reproduction.
This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism.
In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents.
The complete set of observable traits of the structure and behavior of an organism is called its phenotype.
What is phenotype?
As a result, many aspects of an organism's phenotype are not inherited. For example, suntanned skin comes from the interaction between a person's phenotype and sunlight; thus, suntans are not passed on to people's children
Albinism in humans is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes due to absence or defect of tyrosinase, a copper-containing enzyme involved in the production of melanin.
Heritable traits are known to be passed from one generation to the next via DNA, a molecule that encodes genetic information.
DNA is a long polymer that incorporates four types of bases, which are interchangeable. The sequence of bases along a particular DNA molecule specifies the genetic information: this is comparable to a sequence of letters spelling out a passage of text. Before a cell divides through mitosis, the DNA is copied, so that each of the resulting two cells will inherit the DNA sequence.
A portion of a DNA molecule that specifies a single functional unit is called a gene; different genes have different sequences of bases. Within cells, the long strands of DNA form condensed structures called chromosomes
Organisms inherit genetic material from their parents in the form of homologous chromosomes, containing a unique combination of DNA sequences that code for genes