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

Legume - development of seeds, Legume - Development of seeds Outer epi...

Legume - Development of seeds Outer epidermis of the ovary usually forms the exocarp of the leguminous pod. Next few cell layers constitute the mesocarp with thick-walled pare

How phosphorus in blood is presented, How Phosphorus in Blood is presented?...

How Phosphorus in Blood is presented? Phosphorus in Blood is Present as: 1.  Inorganic phosphorus in the form of HPO 4 or H 2 PO 4 2.  Organic or ester phosphorus such

Bantham and hookers classification systeam, discribe tha bantham and hooker...

discribe tha bantham and hookers systeam of classification

What are the symptoms associated with campylobacteriosis, What are the symp...

What are the symptoms and foods associated with campylobacteriosis?  Campylobacteriosis incubation period: 2-5 days after ingestion of contaminated food.  Symptoms: Diarrhoe

Excreatory organ, what is the excreatory organ of silverfish?

what is the excreatory organ of silverfish?

Which organ releases the female gamete under formation, Q. What is the orga...

Q. What is the organ that releases the female gamete under formation? How is this release triggered? What is the organ that collects the released gametes? The organ that libera

Regular soda are made with aluminium, If the cans of regular soda are made ...

If the cans of regular soda are made with aluminium than diet soda, then regular soda will sink. Write brief descriptions of how you could test this hypothesis.

Adverse effects, Hypotension, hyperkalemia, taste disturbance, angiedema, r...

Hypotension, hyperkalemia, taste disturbance, angiedema, renal insufficiency. In the absence of any symptoms of hypotension, and normal renal function and K + levels, the dosage

Prevent and control staphylococcal food poisoning, To prevent and control S...

To prevent and control Staphylococcal food poisoning: • Avoid contamination of foods • Kill organism by heating, refrigeration • Personnel hygiene • Adequate cookin

Common causes related with angina pectoris, Q. Common causes related with a...

Q. Common causes related with angina pectoris? • The usual cause of angina is the narrowing of the major coronary artery due to atherosclerosis. • Systemic hypertension inc

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