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

Ecology lab assignment, i need to complete a model on loop analysis Java an...

i need to complete a model on loop analysis Java and answer questions on my assignment sheet....any experts to help me do my lab homework?

Explain xanthan gum, Explain Xanthan Gum Xanthan gum is a microbial pol...

Explain Xanthan Gum Xanthan gum is a microbial polymer prepared commercially in pure culture fermentation from Xanthomonas campestris. This polysaccharide was given the generic

Hydrarch - ecology, Hydrarch - Ecology Its various stages are well stu...

Hydrarch - Ecology Its various stages are well studied in ecosystem like ponds, pools and lakes. Since pond is a fresh water ecosystem, the succession in it is also referred t

What is the menstrual cycle, Q. What is the menstrual cycle? The menstr...

Q. What is the menstrual cycle? The menstrual cycle is the periodic succession of interactions between the organs and hormones of the female reproductive system after the begin

Ethylene - plant growth substances, Ethylene - Plant Growth Substances ...

Ethylene - Plant Growth Substances This hydrocarbon C 2 H 2 is a gas and is unbelievably a small and simple molecule to be accepted as a hormone. Ethylene is not produced by

What is the explanation for the bleeding, Q. What is the explanation for th...

Q. What is the explanation for the bleeding that accompanies menses? The hemorrhage that accompanies menses occurs because the endometrium is a richly vascularized tissue and t

Drug management for gout disease, Q. Drug Management for gout disease? ...

Q. Drug Management for gout disease? Drugs are so effective in lowering the serum mate concentration that rigid restriction of dietary purines is rarely necessary. Uricosurie d

Explain vitamin k as an essential fat soluble micronutrient, Explain Vitami...

Explain Vitamin K as an essential fat soluble micronutrient? Vitamin K is an essential fat-soluble micronutrient the only unequivocal role in health is in the maintenance of no

Explain indinavir, Indinavir (IDV, Crixivan) Indinavir has good oral ...

Indinavir (IDV, Crixivan) Indinavir has good oral bioavailability. Indinavir 800 mg combined with ritonavir 100 mg  (both b.i.d. for ease of use) was comparable in effectiven

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