Question

Link the genetic characteristics to the DNA structure and also list and describe Mendel's principles and describe how each contribute to genetic variability. How might biology have be different if his discoveries had not been lost for decades? Be prepared to discuss the significance of Mendel's discoveries to moder biology.

Answer 1

DNA is basically the language of genetics. Like English DNA has its own alphabets adenine, guanine, cytosine and thymine. Specific DNA regions called genes carry specific information in an organism for its survival which are transferred from an organism to its offsprings. Each gene controls the trait/phenotype of an organism.

Mendel principles

1) law of dominance

Mendel named these genes as factors and observed that for a trait there were two variations which were called alleles and responsible for variations for a trait. Like for heigh there were tall and short height genes. He concluded that one of the allele is dominant over the other while the other is recessive.

2) law of segregation

The two alleles segregate during gamete formation i.e. in a diploid organism, one allele will segregate into one gamete while the other will have the second allele

3) law of independent assortment

It states that two genes assort independently during gamete formation..

Mendel principles explain genetic variability as follows:

1. The variability in the alleles of the Genes. For height it can be tall or short depending on the allele

2. Law of segregation says that, during gametogenesis, a gamete inherits inherits an allele for a gene randomly.