What is the principle of genetic?

Answer 1

The Principle of Segregation. The principle of segregation says that in diploid organisms genes come in pairs and that when gametes get produced each gamete gets one gene at random from each gene pair but not both. When developing this idea Gregor Mendel conducted a series on monohybrid crosses using pea plants.

Monohybrid cross: A monohybrid cross is a cross in which the breeder starts out with parents that are true breeding for alternate forms of a characteristic, for example flower color.

Procedure for monohybrid cross

Step 1. Produce parents true breeding for alternate forms of the trait or characteristic being studied. For instance were we studying the inheritance of flower color in peas as Mendel did we would selectively breed for plants that only produced purple flower offspring when bred with themselves. That would be the source of one of the parents. The other parent might be pure breeding for white flowers. These original parents are called the parental generation.

Step 2. Breed these parents together to produce offspring called the F1 generation.

Step 3 Breed the F1 generation offspring with each other to produce the next generation or F2 generation. Examining the appearance offspring resulting from these crosses give us information about the about the pattern of inheritance of the trait being studied.

Some terminology

Phenotype Vs genotype.

Phenotype: The phenotype refers to the appearance of the organism. This could refer to some obvious trait such as purple flower color, or to a biochemical trait such as the particular form of an enzyme. In our example the purple or white rectangles represent the phenotype.

Genotype: The genotype refers to the particular combinations of genes that give rise to the phenotype. In our example the letters represent the genes involved in the genotype. AA individuals and Aa individuals can have the same phenotype, both purple for instance but the genotype is different.

For the true breeding organisms in the parental generation notice that both genes are the same for each individual.

The AA individuals only produce gametes carrying

the A allele. The AA individuals produce only gametes gametes carrying the a allele.

Allele: An allele is an alternate form of a gene. For example while a diploid individual might carry two copies of a gene the copies may not be identical. Perhaps each gene codes for a slightly different form of an enzyme.

Homozygous: Homozygous refers to an individual having both alleles of the gene pair be the same allele. For example both AA and AA individuals are Homozygous.

Heterozygous: Heterozygous refers to an individual having different (non- identical) alleles for each gene in the gene pair. For instance the Aa individuals produced from the cross AA x AA are heterozygous.

F1 generation: F1 stands for first filial generation. These are the offspring from a particular set of parents during a monohybrid or other sort of genetic cross.

F2 generation. The F2 or second filial generation refers to the offspring of the F1 generation when F1's are crossed.

Answer 2

Genetic engineering involves manipulation of the genetic material towards a desired end in a direct and pre-determined way. This is alternatively called recombinant DNA technology.

Answer 3

Genetic engineering is the process of making genetically modified organisms. It involves adding, removing, and replacing DNA or whole genes from the organism's genome.