Please forward this error screen to as9101 rev f pdf. This article is about the transfer of characteristics from parent to offspring.
Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. The study of heredity in biology is called genetics, which includes the field of epigenetics. Heredity of phenotypic traits: Father and son with prominent ears and crowns.
In humans, eye color is an example of an inherited characteristic: an individual might inherit the “brown-eye trait” from one of the parents. Inherited traits are controlled by genes and the complete set of genes within an organism’s genome is called its genotype. The complete set of observable traits of the structure and behavior of an organism is called its phenotype.
These traits arise from the interaction of its genotype with the environment. As a result, many aspects of an organism’s phenotype are not inherited.
However, some people tan more easily than others, due to differences in their genotype: a striking example is people with the inherited trait of albinism, who do not tan at all and are very sensitive to sunburn. 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. 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.