Common drugs tied to increased risk of cognitive decline

A class of drugs used for many conditions, including allergies, colds, high blood pressure and depression, may be associated with an increased risk of developing mild thinking and memory problems, particularly in people who ...

Diseases, Conditions, Syndromes

Genetic mutations predispose individuals to severe COVID-19

Current observations suggest that the coronavirus SARS-CoV-2 causes severe symptoms mainly in elderly patients with chronic disease. However when two pairs of previously healthy young brothers from two families required mechanical ...

Diseases, Conditions, Syndromes

Reducing the risk of infection

"Biology shows us that there are additional ways to reduce the risk of serious coronavirus infections, in addition to hand hygiene and keeping distance," Viola Vogel writes.

Diseases, Conditions, Syndromes

I've been diagnosed with COVID-19. What should I expect?

As doctors and care providers work to reduce the spread of the new coronavirus and COVID-19, the disease it causes, people are trying to understand what to do if they receive a COVID-19 diagnosis. Lisa Maragakis, senior director ...

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Genetics (from Ancient Greek γενετικός genetikos, “genitive” and that from γένεσις genesis, “origin”), a discipline of biology, is the science of heredity and variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the process of inheritance, only began with the work of Gregor Mendel in the mid-nineteenth century. Although he did not know the physical basis for heredity, Mendel observed that organisms inherit traits via discrete units of inheritance, which are now called genes.

Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides—the sequence of these nucleotides is the genetic information organisms inherit. DNA naturally occurs in a double stranded form, with nucleotides on each strand complementary to each other. Each strand can act as a template for creating a new partner strand—this is the physical method for making copies of genes that can be inherited.

The sequence of nucleotides in a gene is translated by cells to produce a chain of amino acids, creating proteins—the order of amino acids in a protein corresponds to the order of nucleotides in the gene. This relationship between nucleotide sequence and amino acid sequence is known as the genetic code. The amino acids in a protein determine how it folds into a three-dimensional shape; this structure is, in turn, responsible for the protein's function. Proteins carry out almost all the functions needed for cells to live. A change to the DNA in a gene can change a protein's amino acids, changing its shape and function: this can have a dramatic effect in the cell and on the organism as a whole. Two additional factors that can change the shape of the protein are pH and temperature.

Although genetics plays a large role in the appearance and behavior of organisms, it is the combination of genetics with what an organism experiences that determines the ultimate outcome. For example, while genes play a role in determining an organism's size, the nutrition and other conditions it experiences after inception also have a large effect.

This text uses material from Wikipedia, licensed under CC BY-SA