Explain the mendel''s laws in genetics, Biology

Assignment Help:

Explain the Mendel's Laws in genetics?

Based on the results of his experiments, Mendel proposed three laws regarding the inheritance of traits: the Law of Segregation, the Law of Independent Assortment, and the Law of Dominance.

The first principle proposed by Mendel, the Law of Segregation, states that "factors" responsible for inheritance of traits remain separate in the offspring, rather than blending . Because traits not apparent in the F1 generation reappeared in the F2 generation, and the F2 generation also had two factors, Mendel concluded that each parent carried two factors that segregate, or separate, during the formation of sperm or egg cells so that they each carry only one factor; therefore the offspring had two factors, the same as the parent.
Since Mendel studied a number of traits, he found that alleles governing different traits, such as position of flowers along the stem; position, shape, and color of the pod; height of the plant; seed texture, seed color, and seed coat color, segregate independently from the alleles that govern another trait. This formed the basis of the second principle, the Law of Independent Assortment. We will see that this law applies only to genes found on different chromosomes.

The third principle, the Law of Dominance, was a result of Mendel's discovery that when two strains were cross-pollinated, one factor in a pair, the dominant factor, may mask the other, so that the dominant trait is always observed in the F1 generation. He called a factor recessive if the trait did not appear until the F2 generation. Some traits were found to exhibit incomplete dominance; that is, heterozygous plants had phenotypes intermediate between the dominant and the recessive. An example is a dominant red flowered plant and recessive white-flowered producing pink-flowered offspring. If dominant traits produce different phenotypes, and both appear in heterozygotes, the traits are called codominant.

539_variations on the mendelian theme.png

There are traits such as skin color in humans that have more than two phenotypes and result from contributions from two or more genes. This condition is called polygenic inheritance. In its simplest form, two genes code for the same trait; an example is kernel color in wheat, where two genes have two alleles, R for red pigment and R' for no pigment at all. The resulting phenotypes exhibit incomplete dominance as with heterozygous single alleles, but there are more shades of red because there are more genes contributing to the trait.


Related Discussions:- Explain the mendel''s laws in genetics

How many will be homozygous for dominant allele, In a Population that is in...

In a Population that is in Hardy-Weinberg equilibrium, the frequency of the recessive Homozygous genotype is 0.49. The frequency of individuals Homozygous for the Dominant allele i

Define water as a temperature regulator, Define Water as a temperature regu...

Define Water as a temperature regulator? Water plays an important role in the distribution of heat throughout the body and the regulation of body temperature. Heat is generate

Draw decanol, Draw decanol, plamitic acid (C16:0 fatty acid) and the result...

Draw decanol, plamitic acid (C16:0 fatty acid) and the resulting wax ester generated by a dehydration reaction between both molecules.

How many asymmetric the amino acid serine have, How many asymmetric carbons...

How many asymmetric carbons does the amino acid serine have? Please explain with a strucutral diagram if possible.

Antiparkinsonian drugs, Antiparkinsmian Drugs: Antiparkinsonian drugs ...

Antiparkinsmian Drugs: Antiparkinsonian drugs are  the  specific drugs  to treat the extrapynnidal side effects  of  antipsychotic agents.  Anticholinergic drugs  block

What would be the knowledge of regeneration, A 19 year old model for Glamou...

A 19 year old model for Glamour magazine tripped over an extension cord causing injury to her epidermis. She is afraid the injury will leave a scar. Based on your knowledge of rege

Define some features of penicillium, Define some features of Penicillium? ...

Define some features of Penicillium? The identifying features of Penicillium are: 1. Mycelium consists of colourless, septate and branched hyphae, some of which grow inside

Example of a fixed joint, Give one example in each case of (a) a fixe...

Give one example in each case of (a) a fixed joint, (b) a ball and socket joint, (c) a hinge joint.   (a) The bones of the skull, the junction of pelvic gi

Enumerate various factors controlling osseointegration, Q. Enumerate variou...

Q. Enumerate various factors controlling osseointegration? The factors controlling osseointegration are: i) Occlusal load ii) Biocompatibility of the material iii) Imp

How sugar play a major role in preservation, How sugar play a major role in...

How sugar play a major role in preservation? In so many products, sugars play a major role in preservation. The addition of monosaccharides, like glucose or fructose, to jams a

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd