Genetics is the study of inheritance in living organisms.
The same molecular processes that provide a mechanism for organisms to pass
Genetic information to their offspring leads to the gradual change of species over time, providing for biodiversity and evolution of new species.
Topics covered in this snack-sized chapter:
DNA is the material that carries all the information about how a living thing will look and function.
For instance, DNA in humans determines such things as what color the eyes are and how the lungs work.
Each piece of information is carried on a different section of the DNA. These sections are called genes.
DNA is short for deoxyribonucleic acid. It is in every cell of every living thing.
DNA is found in structures of the cell called chromosomes.
Both DNA and chromosomes are tiny.
Scientists need to use very powerful microscopes to see them.
Genetic Inheritance is the passing of traits to offspring from its parents or ancestor.
This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism.
It is the act of inheriting property
The reception of genetic qualities by transmission from parent to offspring
The acquisition of a possession, condition, or trait from past generations
Each gene has its own specific location on the chromosome or on the mitochondrial DNA.
The gene performs a single important function.
These serve as blueprints for a physical, physiological or mental trait.
The genes tell how a person looks like hair, eye, skin color, shape of the body and features, height etc.
The DNA code is made up of very long chains of four basic building blocks (nucleotide bases):
The chromosome contains two of the DNA chains running in opposite directions; the bases pair up to form the rungs of a ladder twisted into a double helical structure.
Adenine (A) can only pair with base Thymine (T), and vice versa; and base Guanine (G) can only pair with base Cytosine (C), and vice versa.
DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance.
The process starts when one double-stranded DNA molecule produces two identical copies of the molecule.
The cell cycle (mitosis) also pertains to the DNA replication/reproduction process.
The cell cycle includes:
The genetic code undergoes several changes during the process of evolution.
However, despite such changes, there is preservation of the majority of characteristics of the species.
Several discoveries have made genetic research one of the fastest developing research areas in the world today.
With the understanding of genetic basis of disease there is a rapid development of genetic basis for disease risk and diagnosis and treatment.
Genetic engineering has also made progress over the last few decades.
Organisms used in genetic research: Certain organisms formed the origins of genetic research experiments. Gregor Mendel for example discovered theories of inheritance from sweet pea plants.