Mendel's Laws, DNA, Genes, and the Genetic Code

Mendel's Laws

Mendel explained the observations made during years of crossing different types of peas in the gardens of a monastery. He collected the general laws of inheritance that later became known as Mendel's laws.

Double Helix DNA

DNA carries the genetic information. DNA is a molecule composed of four simple units, repeated often and combined in different ways (called nucleotides). There are four types of DNA nucleotides: cytosine, guanine, thymine, and adenine. A single DNA molecule is formed by two chains of nucleotides linked and facing each other, with a structure that forms a spiral staircase: a double helix.

Replication of DNA

DNA contains genetic information. When the cell divides, it is capable of making an exact copy of the entire DNA so the daughter cells can inherit it.

Chromosomes

DNA is packaged into structures called chromosomes (approximately). Each chromosome consists of a molecular DNA surrounded by proteins. Karyotype is the set of chromosomes of an organism.

Genes

A gene is a DNA fragment that encodes the synthesis of a specific protein. A gene is the unit of genetic information. Genotype is the genetic constitution of an organism with respect to a specific character. The phenotype is the manifestation of the genotype, the attributes that we see in an organism due to genetic information.

Proteins

Proteins are made up of amino acids. There are a total of 20 different amino acids, so the number of possible proteins is infinite. The function of each protein is characterized by its amino acid sequence.

Protein functions:

• Protect and give form
• Waterproof
• Adaptation: substances activate defense mechanisms
• Produce movement
• Pack hereditary material
• Promote signals or perform biochemical reactions

The Genetic Code

The genetic code can be translated. Keep in mind that there must be a relationship between gene nucleotides and amino acids of a protein.

Messenger RNA

The ribosomes are the "manufacturers" of proteins, responsible for decoding the genetic information and constructing proteins by combining amino acids. DNA is enclosed within the nucleus. For the transfer of genes into the cytoplasm, without jeopardizing the DNA, "photocopies" are used. RNA is formed similarly to DNA.