what is polygenic inheritance course hero

by Jabari Fay 7 min read

Polygenic Inheritance is produced by the cumulative effect of many genes. It is a form of non-Mendelian

Mendelian inheritance

Mendelian inheritance is inheritance of biological features that follows the laws proposed by Gregor Johann Mendel in 1865 and 1866 and re-discovered in 1900. It was initially very controversial.

inheritance which deviates from the typical phenotypic Mendelian ratio. Polygenic Inheritance is found in both animals and plants. No two people can be exactly the same; even the twins have minute differences in them.

Full Answer

What is polygenic inheritance?

Polygenic inheritance should not be confused with the effects caused by multiple alleles. In the case of multiple alleles, a gene contains several different allele variants on the same locus of each chromosome, for example the three different alleles which control for blood type – A, B & O.

What is the effect of Environment on polygenic inheritance?

Effect of environment on Polygenic Inheritance The expression of polygenes is greatly influenced by environmental conditions. The genotype sets the range for a quantitative trait, but the environmental conditions decide the phenotype within its genetic limits. Genes function differently in different environmental conditions.

What is an example of a polygenic trait?

Three examples of polygenic traits in humans are height, skin colour and eye colour. These traits are governed by multiple genes. Is blood type an example of polygenic inheritance?

How does polygenic inheritance differ from multiple alleles?

Polygenic inheritance differs from multiple alleles, as in multiple alleles, three or more alleles are present in the same locus of which any two alleles are present in an organism, e.g. ABO blood group system, which is controlled by three alleles There is no epistasis involved, i.e. masking of the expression of an allele of the different locus

What is meant by polygenic inheritance?

the heredity of complex characters that are determined by a large number of genes, each one usually having a relatively small effect.

What is polygenic inheritance Ncert?

Polygenic inheritance is when more than one gene controls a character. It is also known as quantitative inheritance where two or more different pair of alleles which have a cumulative effect on governing quantitative characters.

What is polygenic inheritance Ncert 12?

(a) Polygenic inheritance is an inheritance pattern controlled by three or more genes (multiple genes) and the graded phenotypes are due to the additive or cumulative effect of all the different genes of the trait. An example of human skin colour to understand the phenomenon of polygenic inheritance.

What are polygenic traits explain with an example?

Polygenic traits have a bell-shaped distribution in a population with most individuals inheriting various combinations of alleles and falling within the middle range of the curve for a particular trait. Examples of polygenic traits include skin color, eye color, hair color, body shape, height, and weight.

What are polygenic traits Mcq?

2. What are polygenic traits? Explanation: Traits are the feature of a character by which we can distinguish organisms. Traits which are generally controlled by three or more genes are known as polygenic traits.

Why is polygenic inheritance important?

The statistical analysis of polygenic inheritance patterns can help to provide an estimate of population parameters. Most of the polygenic inheritance follow the normal distribution curve, wherein the majority of the people fall in the middle range of the curve.

Who discovered polygenic inheritance?

Nils Herman Nilsson-Ehle and Edward Murray East Develop the Theory of Polygenic Inheritance. Nils Herman Nilsson-Ehle. , advanced the "multiple factor" theory, or theory of polygenic inheritance, in which a trait is produced from the cumulative effects of more than one gene.

Which one of the following is an example of polygenic inheritance?

So, the correct answer is 'Skin colour in humans'.

What is polygenic inheritance?

Polygenic inheritance, also known as quantitative inheritance, refers to a single inherited phenotypic trait that is controlled by two or more different genes. In a system which differs from Mendelian Genetics, where monogenic traits are determined by the different alleles of a single gene, ...

What are the physical traits that are controlled by polygenic inheritance?

Because of the inheritance mode patterns, the physical traits that are controlled by polygenic inheritance, such as hair color, height and skin color, as well as the non-visible traits such as blood pressure, intelligence, autism and longevity, occur on a continuous gradient, with many variations of quantifiable increments.

What is additive effect in polygenic inheritance?

It is important to remember here that in polygenic inheritance, alleles do not display dominance over others, rather, each contributing allele gives an additive effect rather than a masking effect, and so the way that the alleles interact is different to those in Mendelian genetics. The additive effect means that each contributing allele produces ...

How are polygenic traits determined?

Polygenic traits are determined by the interactions between several different genes, which display incomplete dominance. 2. How many different allele combinations can possibly be produced from two parents that are heterozygous for a polygenic trait controlled by three different genes with two allele pairs? A. 5. B. 7.

How many genes are involved in human height?

Human Height. Human height is an extremely complex inheritance pattern as there are over 400 genes controlling for it, it is therefore extremely difficult to predict the height that an offspring will be; two short parents may produce a tall child, whereas two tall parents can produce a short child and parents with completely different heights may ...

Which set of theories attempted to explain the inheritance patterns of genetic characteristics based on simple breeding experiments?

Mendelian Genetics – The set of theories proposed by Gregor Mendel, which attempt to explain the inheritance patterns of genetic characteristics based on simple breeding experiments involving single genes on chromosome pairs.

What is the difference between genotype and phenotype?

Genotype The genetic makeup of an individual organism. Phenotype – The physical and biological characteristics expressed in an individual as determined by their genotype. Epistasis – The interactions between separate genes, in which one masks the effect of another.

What is polygenic inheritance?

“Polygenic inheritance is defined as quantitative inheritance, where multiple independent genes have an additive or similar effect on a single quantitative trait.”. Polygenic inheritance is also known as multiple gene inheritance or multiple factor inheritance.

What are some traits that show polygenic inheritance?

There are many traits in humans, which show polygenic inheritance, e.g. skin and hair colour, height, eye colour, the risk for diseases and resistance, intelligence, blood pressure, bipolar disorder, autism, longevity, etc. Brief description of some of the traits:

What determines the phenotype of a trait?

The genotype sets the range for a quantitative trait, but the environmental conditions decide the phenotype within its genetic limits. Genes function differently in different environmental conditions. Environment regulates the activity of certain genes and sets them on or off.

How does polygenic inheritance differ from multiple alleles?

Polygenic inheritance differs from multiple alleles, as in multiple alleles , three or more alleles are present in the same locus of which any two alleles are present in an organism, e.g. ABO blood group system, which is controlled by three alleles. There is no epistasis involved, i.e. masking of the expression of an allele of the different locus.

How many genes are involved in the expression of phenotype for the length of the corolla?

63 Red (many shades):1 (white) Length of the corolla in tobacco: There are around 5 genes involved in the expression of phenotype for corolla length of tobacco. There is a wide variety in the length of the corolla in tobacco due to polygenic inheritance.

What is a polygene?

Polygene refers to a gene that exerts a slight effect on a phenotype along with other genes. Effect of a single gene is too small, so it is difficult to detect. Multiple genes produce an equal effect. Each allele has a cumulative or additive effect.

How are traits and phenotypic characters present in plants and animals inherited?

Many traits and phenotypic characters present in plants and animals such as height, skin pigmentation, hair and eye colour, milk and egg production are inherited through many alleles present in different loci. This is known as polygenic inheritance.

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