Genetics, Chromosomes, Genotype and Phenotype.
genetics - human genetics - genetics basics - genetics definition - department of genetics - chromosomes - chromosome - Phenotype - genotype - gene - DNA - alleles - inherited - dna - molecular genetics - Mendel - offspring - gametes - cross-pollination
.jpg "Genetics, Chromosomes, Genotype, Phenotype.")
What is genetics ?
Genetics is the scientific study of heredity, the mechanisms and patterns of gene transmission from parents to offspring. Genetics is primarily concerned with genes, the units of heredity, and the mechanisms by which they are copied and transmitted from parent to offspring. Genetics has played a central role in modern biology and has had a profound impact on human life. Closely related fields such as molecular genetics, biotechnology, and genetic engineering are among the most powerful scientific disciplines in modern society.
Or, Genetics is the study of the mechanisms of heredity, the study of the genes, their structure and function, and the way they transmit traits to offspring. Genetics underlies all other biological sciences, providing the framework for understanding biological phenomena such as the mechanisms of inheritance, the causes of disease, and the evolution of species. It underlies the modern medicine and agriculture, and has become an integral part of the economy.
Genetics is concerned not just with how genes are passed on from parent to offspring but also with how they give rise to the traits and characteristics that we see in the individuals and populations that possess them.
Discovery of structure of DNA
The discovery of the double-helical structure of DNA, the molecule that encodes genetic information, in 1953 by James Watson and Francis Crick has been described as one of the greatest achievements in the history of science. Since then, genetics has been at the forefront of the modern study of biology and medicine
Genetics is one of the central pillars of biology, and overlaps with a wide range of other disciplines including medicine, agriculture, and biochemistry. Genetics can also be looked at as the study of genes themselves, which form the basis of heredity. Genetics researchers can study genes in a range of contexts, including in the human body, in plants and animals, and in microbes such as bacteria and viruses.
Modern genetics focuses on the chemical substance that genes are made of, which is called deoxyribonucleic acid, or DNA, and the ways in which it affects the chemical reactions that constitute the living process we call biology. Genetics also encompasses the study of heredity in general, including the ways in which genes are inherited from parents to children; the ways in which genes are altered, or mutated, in the course of a lifetime; and the ways in which genes are transferred from one generation to another, via the mechanism of sexual reproduction. The field of genetics also encompasses the study of the genes themselves, the mechanisms by which they are inherited from parents to children, the mechanisms by which they are altered or mutated in the course of a lifetime
Evolution of genetics
The science of genetics, which seeks to understand the mechanisms of heredity and the material basis of genes, has evolved over the past century into one of the preeminent disciplines in the biological sciences.
Mendel and genetics
The modern study of genetics can be traced back to the work of Gregor Mendel, who analyzed the patterns of inheritance in plants. in the middle of the 19th century, Mendel suspected that traits were inherited as discrete units, and, although he knew nothing of the function of genes, his experiments with inheritance set the scene for genetics as we now know it.
All present-day research in genetics can be traced back to the discovery of the laws governing the inheritance of traits, made by Gregor Mendel in the 19th century. The discovery of genes and their functions, together with their biochemical nature, The field has since expanded to investigate the cause and effect relationship between genes and the properties and behaviors they influence, and the mechanisms by which genetic material is passed from parent to offspring. The study of genetics is also known as genetics or genetic inheritance.
Mendel's genetic experiments
The study of genetics, the scientific discipline concerned with the mechanisms of heredity, has been one of the most powerful tools in the discovery of the mechanisms that transmit traits from parents to offspring. The field of genetics has its roots in the work of Gregor Mendel, who conducted the first experiments to investigate the mechanisms of heredity. These experiments are often considered to have been the first scientific studies in genetics, and they laid the foundation for the modern study of genetics. In his monastery garden, Mendel carried out a large number of cross-pollinations between different varieties of plants, such as peas. Before Gregor Mendel carried out the experiments, theories of a hereditary mechanism were largely based on speculation rather than experimentation.
Mendel is best known for his experiments with plants. He studied genetics, the scientific study of heredity. He was particularly interested in the mechanisms by which traits are passed from parent to offspring. He carried out a large number of cross-pollination experiments with variants of the garden pea, which he obtained as pure-breeding lines.
Gregor Mendel carried out a large number of cross-pollination experiments between variants of the garden pea, which he obtained as pure-breeding lines. He crossed peas with yellow seeds to those with green seeds and observed that the progeny seeds which in the first generation, F1 were all yellow. When the F1 individuals were self-pollinated or crossed among themselves, their progeny (F2) showed a ratio of 3 : 1 (3/4 yellow and 1/4 green) or 75% yellow : 25% green.
In the F1 generation, the two parental lines were proposed to be YY (yellow seeds) and yy (green seeds). The gametes from these lines were Y and y, respectively, thereby producing an F1 generation of Yy that were yellow in colour because the dominant allele for yellow seeds was inherited from the YY parent.
In the F1 generation, half the gametes were Y and the other half were y, making the F2 generation produced from random mating 1/4 YY , 1/2 Yy , and 1/4 yy, ( 3:1 ratio ). The forms of the pea colour genes, Y and y, are called alleles.
Modern genetics
The word genetics was introduced in 1905 by English biologist William Bateson, who was one of the discoverers of Mendel’s work and who became a champion of Mendel’s principles of inheritance. He is often called the father of genetics, and he is regarded as such in the scientific literature. His work formed the basis of modern genetics. Specifically, he is regarded as the father of the science of genetics, which studies the molecular mechanisms and the genetic factors that control the characteristics of organisms and cells.
Although genetics is a relatively new science, much of what we know about genetics has been discovered in the past 150 years. One of the main objectives of genetics is to understand the molecular basis of heredity, which is the study of the way in which genes are passed from parent to offspring.
Today, genetics plays a central role in the field of biology, and has been extended to the study of DNA and the cellular mechanisms through which genes exert their effects. The discovery of the molecular structure of DNA, a molecule that transmits the genetic blueprint from generation to generation, was one of the great scientific triumphs of the twentieth century.
Discovery of genetics
The first recorded observation of the genetic principle was the discovery by Tartaglia in the 15th century that the colloquialism “like father, like son” has a basis in heredity. In the 19th century, the Italian doctor G.B. Lamarck postulated that the characteristics of organisms are acquired through their experiences and passed on to their offspring. However, the discovery of genetics as a science by Gregor Mendel in the 1860s led to the modern understanding that heredity is passed on from parent to offspring in the form of genes. This discovery, combined with other developments in biology, led to the birth of genetics, the study of genes and heredity.
Structure of chromosomes
Chromosomes contains the genes needed to make a specific type of molecule in the cell. The DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that help the DNA maintain its shape.
Structure of DNA
DNA is a molecule that contains the genes that determine an organism’s traits. Each cell in a person’s body has the same DNA, and this DNA is the source of the genes that determine that person’s traits. But a person’s genes are not the only part of DNA that determines their traits. It is the sequence of nucleotides in the DNA that encodes a gene, and therefore determines the trait that the gene represents
Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). Mitochondria are structures within cells that convert the energy from food into a form that cells can use.
Chromosomes and genotype
Genotype is used to refer to the pair of alleles present at a single locus. With alleles 'A' and 'a' there are three possible genotypes AA, Aa and aa. The genome in which a genotype is found can affect the expression of that genotype, and the environment can affect the phenotype
Chromosomes and phenotype
Phenotype is the collection of all the physical and behavioral traits that can be observed in an organism. The phenotype is determined by the genotype—the genetic makeup of an organism. Unlike the phenotype, which is inherited from parents, the genotype is the combined genetic material of the parents. It is the genotype that determines the range of possible phenotypes an organism can have, and determines the organism’s ability to pass on their genes to the next generation or The phenotype of an organism is the set of characteristics that can be observed, such as the color and shape of a human being.
The genotype of an organism, on the other hand, is the set of genes that an organism inherits from its parents. Unlike the phenotype, which can be observed, the genotype is a set of genes and is therefore not directly observable. The phenotype is determined by the genotype, but not all members of a species will have the same set of observable characteristics
Genetics is the study of the mechanisms of heredity and the variation of organisms caused by those mechanisms. The field of genetics can be further broken down into sub-fields, such as genotype, which is the genetic material of an organism, and phenotype, which is the set of observable characteristics of an organism. The sum of an organism’s observable characteristics is their phenotype. A key difference between phenotype and genotype is that, whilst genotype is inherited from an organism’s parents, the phenotype is influenced by environmental factors as well as genetics
Dr. Mohammed mabrouk salama
.jpg&description=Genetics, Chromosomes, Genotype and Phenotype. genetics - human genetics - genetics basics - genetics definition - department of genetics…){kind=link}
تعليقات
إرسال تعليق