Nuclein were discovered by Friedrich Miescher in Nucleic acids were named for their initial discovery within the nucleusand for the presence of phosphate groups related to phosphoric acid. The chemical methods also enable the generation of altered nucleic acids that are not found in nature,  for example peptide nucleic acids.
Inheritance in biology[ edit ] Genes and inheritance[ edit ] A section of DNA ; the sequence of the plate-like units nucleotides in the center carries information.
Red hair is a recessive trait. Genes are inherited as units, with two parents dividing out copies of their genes to their offspring. This process can be compared with mixing two hands of cards, shuffling them, and then dealing them out again.
Humans have two copies of each of their genes, and make copies that are found in eggs or sperm—but they only include one copy of each type of gene. An egg and sperm join to form a complete set of genes. The eventually resulting offspring has the same number of genes as their parents, but for any gene one of their two copies comes from their father, and one from their mother.
If the father has two copies of an allele for red hair, and the mother has two copies for brown hair, all their children get the two alleles that give different instructions, one for red hair and one for brown.
The hair color of these children depends on how these alleles work together. If one allele dominates the instructions from another, it is called the dominant allele, and the allele that is overridden is called the recessive allele.
In the case of a daughter with alleles for both red and brown hair, brown is dominant and she ends up with brown hair. This is a difference between what you see on the surface the traits of an organism, called its phenotype and the genes within the organism its genotype.
In this example you can call the allele for brown "B" and the allele for red "b". It is normal to write dominant alleles with capital letters and recessive ones with lower-case letters. The brown hair daughter has the "brown hair phenotype" but her genotype is Bb, with one copy of the B allele, and one of the b allele.
Now imagine that this woman grows up and has children with a brown-haired man who also has a Bb genotype. Her eggs will be a mixture of two types, one sort containing the B allele, and one sort the b allele.
Similarly, her partner will produce a mix of two types of sperm containing one or the other of these two alleles. In this generation, there is therefore a chance of the recessive allele showing itself in the phenotype of the children—some of them may have red hair like their grandfather.
This can happen when there are several genes involved, each contributing a small part to the end result. Tall people tend to have tall children because their children get a package of many alleles that each contribute a bit to how much they grow.
However, there are not clear groups of "short people" and "tall people", like there are groups of people with brown or red hair. This is because of the large number of genes involved; this makes the trait very variable and people are of many different heights.DNA contains the genetic information that allows all modern living things to function, grow and reproduce.
However, it is unclear how long in the 4-billion-year history of life DNA has performed this function, as it has been proposed that the earliest forms of life may have used RNA as their genetic material. All living things are made up of cells, which is the smallest unit that can be said to be alive.
An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular). All living organisms store genetic information using the same molecules — DNA and RNA.
Written in the genetic code of these molecules is compelling evidence of the shared ancestry of all living things. Evolution of higher life forms requires the development of new genes to support different body plans and types of nutrition. They are found in abundance in all living things, Deoxyribonucleic acid (DNA) is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms.
The DNA segments carrying this genetic information are called genes. Likewise, other DNA sequences have structural . A cell is like a miniature and very complex factory that can make all the parts needed to produce a copy of itself, which happens when cells divide.
There is a simple division of labor in cells—genes give instructions and proteins carry out these instructions, tasks like building a new copy of a cell, or repairing damage. Only living or dead things can have DNA. Go. science math history literature technology health law business All Sections.
DNA is what makes you you it is a nucleic acid thatcontains genetic instructions used in the development andfunctioning of all living organisms and some viruses.