How does polygenic traits result in continuous variation?

Polygenic traits are traits that rely on multiple genes. Continuous variation describes traits whose phenotypes occur on a continuum, rather than having a limited number of possible phenotypes.

Are polygenic traits continuous?

​Polygenic Trait

Traits that display a continuous distribution, such as height or skin color, are polygenic. … Many polygenic traits are also influenced by the environment and are called multifactorial.

Why do phenotypes of polygenic characteristics show continuous variation?

Continuous variation

Most characteristics are controlled by more than one gene and are described as being polygenic . Polygenic characteristics have phenotypes that can show a wide range of values, with each value following on from the value before. This is described as continuous variation .

Which type of traits show continuous variation?

For any species, a characteristic that changes gradually over a range of values shows continuous variation. Examples of such characteristics are: weight. hand span.

Why is continuous variation?

Two reasons for continuous variation: … Differences in external environmental conditions also produce continuous variation. In nature, each character will be influenced by many environmental variables, some tending to increase it, others to decrease it.

What is continuous variation?

Continuous variation is where the different types of variations are distributed on a continuum. On the other hand, discontinuous variation is where the different types of variations are placed into discrete categories.

What causes discontinuous variation?

Discontinuous variation is controlled by alleles of a single gene or a small number of genes. The environment has little effect on this type of variation. … Continuous variation is the combined effect of many genes (known as polygenic inheritance) and is often significantly affected by environmental influences.

How does discontinuous variation differ from continuous variation?

Continuous variation is a variation that has no limit on the value that can occur within a population. Discontinuous variation is a variation that has distinct groups for organisms to belong to. Continuous variation has a predictable direction, The direction of the discontinuous variation is unpredictable.

What causes continuous variation in genetics?

The continuous variation for complex traits is due to genetic complexity and environmental sensitivity. Genetic complexity arises from segregating alleles at multiple loci. The effect of each of these alleles on the trait phenotype is often relatively small, and their expression is sensitive to the environment.

How do you explain discontinuous variation?

A characteristic of any species with only a limited number of possible values shows discontinuous variation . Human blood group is an example of discontinuous variation. In the ABO blood group system, only four blood groups are possible (A, B, AB or O).

What is discontinuous variation?

Discontinuous variation refers to things like eye colour or blood group, which have a limited number of possible values. In other words, a person’s blood can be A, B, AB or O, but it can’t be anything in between.

How is discontinuous variation plotted?

Discontinuous data can be plotted on a bar chart. For example, a person can only have one of four blood groups – A, B, AB or O. Continuous data is plotted on a histogram, this shows a range of measurements from one extreme to another. The curve that the graph produces is know as normal distribution.

Which of the following is an example of discontinuous variation?

Human blood group is an example of discontinuous variation. In the ABO blood group system, only four blood groups are possible (A, B, AB or O). There are no values in between, so this is discontinuous variation. Here are some examples: blood group, relationship (male or female), eye color etc.

What is the difference between continuous and discontinuous data?

Discrete data is information that can only take certain values. … Continuous data is data that can take any value. Height, weight, temperature and length are all examples of continuous data.

What is continuous and discontinuous data biology?

Definition. Continuous variation refers to the type of genetic variation, which shows an unbroken range of phenotypes of a particular character in the population while discontinuous variation refers to the type of genetic variation, which shows to or more separate forms of a character in the population.

Why is tongue discontinuous variation?

The ability to roll the tongue, and blood groups, are examples of discontinuous variation. These characteristics can be explained much more easily by simple rules of genetics and are less likely to be affected by other factors.

Is left handedness an example of discontinuous variation?

Discontinuous Variation

This type of variation has distinct groups or categories which individuals fit into. Tongue rolling, handedness (left or right) and blood groups are examples.

What graph do you use for discontinuous variation?

We usually us a bar chart for discontinuous variation data: We usually us a line graph for continuous variation data: This means that living things will naturally show variation (they will be different to each other).

Are fingerprints continuous or discontinuous variation?

Your height, weight, finger length and so on, would have changed throughout your life (continuous), but your blood type, earwax type, fingerprints and relationship, do not (discontinuous). Like in most examples of discontinuous variation, earwax type is controlled by a single gene with two alleles.

Is intelligence discontinuous variation?

The nature of intelligence is composite and complex, and its expression is dependent upon a combination of environmental effects and the products of a great number of genes. …

Are earlobes continuous or discontinuous?

Here, when you organize your ear cards into a continuous spectrum, you’re describing earlobe shape as a continuous trait, ranging from free to attached. Scientists usually consider continuous traits to be complex traits.

What are some examples of traits that appear to change continuously?

Instead of being measured discretely, they are often represented as a range of continuous variation. Some examples of polygenic traits are height, skin color, eye color, and hair color.

What is discontinuous variation Igcse biology?

Discontinuous Variation is when there are distinct differences for a characteristic. For example, people are either blood group A, B, AB or O; are either male or female; can either roll their tongue or not – there are no ‘inbetweens’

Who discovered discontinuous variation?

William Bateson
Born 8 August 1861 Whitby, Yorkshire
Died 8 February 1926 (aged 64) Merton
Nationality British
Alma mater St. John’s College, Cambridge