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

State the effects of smoking for diabetics patient, State the Effects of al...

State the Effects of alcohol and smoking for diabetics patient A major concern with alcohol consumption is the potential danger of hypoglycaemia (low blood sugar), especially w

Define primary motor cortex corticospinal interneuron a, Define Primary mot...

Define Primary motor cortex corticospinal interneuron A Primary motor cortex (M1) corticospinal interneuron A that produces action potentials during movements of the big toe of

Conformational protection - azotobacter, Conformational Protection - Azotob...

Conformational Protection - Azotobacter In conformational protection a Fe-S redox protein provides protection to the enzyme. The protein gets oxidised in the presence of oxyge

Kreb''s cycle, Kreb's cycle is the biochemical cycle in the cellular aerob...

Kreb's cycle is the biochemical cycle in the cellular aerobic metabolism where the acetyl CoA is combined with the oxaloacetate to form citric acid; the resulting citric acid is c

Hyaluronic acid, H Y ALURONI C ACID It is formed by alternating u...

H Y ALURONI C ACID It is formed by alternating unit of D-glucuronic acid and N-acetylglucosamine. Hyaluronic acid acts as animal cement between adjacent animal cells

What is left ventricular hypertrophy, What is Left Ventricular Hypertrophy ...

What is Left Ventricular Hypertrophy (LVH) ? LVH develops as the response of the heart to chronic pressure or volume overload and is defined as a left ventricular mass exceedin

Transport proteins and under the same concentration gradient, Q. with no sa...

Q. with no saturation of transport proteins and under the same concentration gradient how can the speed of simple diffusion is compared to the speed of facilitated diffusion? T

Fertilization - development biology, Fertilization - Development Biology ...

Fertilization - Development Biology Previously you knew the process which leads to the differentiation of the male and female germ cells, the sperm and ova, respectively. In t

Causes of mitral regurgitation, Q. Causes of Mitral Regurgitation? Mitr...

Q. Causes of Mitral Regurgitation? Mitral regurgitation is the most common valvular abnormality seen in clinical practice. Different disease processes leading to mitral regurgi

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