What are the genetic variations caused by the environment??? What about genetically induced variatio

It is biological variation caused by the environment.

Bar, there is no change in genetic material, it is not heritable, and the variation caused by genetic material can be inherited, such as two brothers, one of them has been working for a long time, **darker, one working indoors, **whiter, this variation is caused by the environment, not inherited, and the white race.

Differences with blacks are heritable due to genetic material.

Environmentally-induced variants are generally genetic diseases controlled by multiple genes....and tends to show familial aggregation. Such as cleft lip, essential hypertension, juvenile diabetes. Genetic variations are generally caused by chromosomal abnormalities, such as crying cat syndrome, also known as trisomy 21, which is an autosomal abnormality.

Gonadal dysgenesis is an abnormal number of sex chromosomes. It is generally caused by environmental pollution.

There are two main types of variation, namely genetic variation and non-heritable variation. Modern genetics shows that non-heritable variation has nothing to do with evolution, but with evolution, it is heritable variation, the former is caused by environmental changes and will not be passed on to offspring, such as thin and short plants due to insufficient water and fertilizer; The latter variant is caused by a change in the genetic material in the form of mutations (including genetic mutations and chromosomal variations) and genetic recombination.

Heritable variations: genetic mutations, genetic recombination, chromosomal variations. For example, albinism and red-green color blindness are genetic mutations that belong to genetic diseases.

And the variation caused by the environment, such as the person himself has a single eyelid and has a double eyelid, this is the variation caused by the environment. Another example is that this person is **white, and basking in the sun makes **temporarily blacken, which is a variation caused by the environment and is not heritable.

This is because it is currently believed that environment-induced variation is mostly reflected in two aspects:

1) Genetic mutations at the genomic level of organisms, such as damage caused by ultraviolet or other rays, which can be passed on to offspring;

2) In the epigenome of organisms, according to research, many epigenetic information of organisms can also be passed on to their offspring.

So the statement that "variation caused by the environment cannot be inherited" is incorrect.

The phenomenon of similarity and dissimilarity between the parents and offspring of living things. One of the essential differences between living and non-living things is that living organisms are capable of self-replication, thus constituting a continuous system of life. Heredity is the phenomenon of offspring repeating the characteristics and characteristics (traits) of their parents in this continuous system, and its essence is the genetic material that is produced by the parents and brings to the offspring to develop according to the traits of the parental genes.

The same genes stipulate that the organism develops the same traits, so it is hereditary, reflecting the stability of the biological world. However, this stability is relative, because the structure of genes will inevitably change at one time or another during the long-term development of generations. Structurally altered genes cause the organism to develop different traits from those before the change, and variations (heritable variations) appear.

Heritable variation gives new content to heredity, and also enables the continuous development and evolution of the long life continuum of living things. Without heredity, it is impossible to maintain the relative stability of traits and species; Without variation, no new traits will be produced, and there can be no evolution of species and selection of new varieties.

Any trait of an organism is developed under the influence of certain environmental factors. The development of a trait cannot be without the genes that develop that trait, nor can it be without the environmental factors that develop that trait. For example, hares and rabbits are fed the same feed with yellow pigment, and the rabbit has a gene that can encode the enzyme that decomposes yellow pigment (from the feed), so the subcutaneous fat of the hare is white; Many strains of rabbits only have genes that do not encode this enzyme, so the yellow pigment in the feed is stored in the subcutaneous fat, making the subcutaneous fat yellow.

The environmental factors here are exactly the same, but the traits of development are different because of the different genes. If all the yellow pigment in the feed is destroyed, the subcutaneous fat of the rabbit is the same white as that of the hare. If the rabbit is fed with yellow pigment, the subcutaneous fat will be yellow again.

At this time, there is no genetic variation in rabbits, but the feed conditions have changed, and the traits expressed are different. Therefore, the traits developed by an organism are the result of the interaction of genetic material (genes) and environmental conditions. Variations due to different environmental conditions are generally not heritable (non-hereditary variation) because they do not involve changes in genetic structure.

The development of quantitative traits (see Quantitative Trait Inheritance) controlled by micro-effect polygenes is more sensitive to changes in environmental conditions and is therefore more prone to non-hereditary variations. Artificial selection should be good at distinguishing between genetic variation and non-genetic variation.

There are two main types of variation: heritable variants and non-heritable variants. Heritable variation is variation caused by changes in genetic material; Non-heritable variations are caused by the environment, and the genetic material has not changed.

For example, if a genetic mutation in a fly causes a change in eye color, it can be passed on to offspring, and this is a mutation that can be inherited.

For example, Weissman did the famous mouse tail cutting experiment, and found that the mouse tail was cut continuously for 22 generations, and the mouse tail did not become shorter. This does not involve variation in genetic material, so it is a non-heritable variation.

Genetic variation is a variation caused by genetic material that can be passed on to future generations. Such as skin color, hair type, coat color. 28. Give examples of variants that are not inherited.

Non-hereditary variation is a variation that is caused solely by environmental factors, and is not hereditary if there is no change that affects the genetic material. Such as double eyelids for surgery, tanning**.

Heredity, in general, refers to the phenomenon that the traits of the parent are represented in the next generation. But in genetics, it refers to the phenomenon of passing genetic material from previous generations to offspring.

Variation refers to the difference between the offspring and the parents of an organism, and the difference between the offspring individuals. One of the properties of a biological organism. There are two main types of variation, namely genetic variation and non-heritable variation.

Modern genetics has shown that non-heritable variation has nothing to do with evolution, but with heritable variation. The former is caused by environmental changes and will not be passed on to offspring, such as thin and short plants due to insufficient water and fertilizer; The latter variant is caused by a change in the genetic material in the form of mutations (including genetic mutations and chromosomal variations) and genetic recombination.

Mutations and genetic recombination are random. It can be a favorable variant or a harmful variant. Thus, variation may or may not be adaptive.

It's just that the environment weeds out the harmful mutations and retains them to adapt to the environment. Therefore, organisms produce mutations that adapt to their environment.

The environment may lead to variations, such as radiation, chemical pollution, microbial infection, etc., the environment determines whether the variation can be passed on from generation to generation (that is, the environment determines the direction of biological evolution), and it is also a process of screening genetic material by the environment, excluding unsuitable genetic sequences, so that organisms can evolve to what they are today.

Not all variation is caused by the environment.

Variation is at the root of biological evolution and human breeding, including both heritable and non-heritable variation.

Environmentally-induced predominantly non-heritable variation.

The main cause of biological variation is generally a change in the genetic material (DNA or RNA).

Gene mutation, genetic recombination, and chromosomal variation are the three main types of biological variation, which belong to heritable variation. Genetic mutations are fundamental to biological variation**.

Physical, chemical, biological, and other factors can all contribute to mutations.

Environmental factors can also cause variation in organisms, which are generally non-heritable.

It should be: Variations caused by the environment cannot be inherited if the genetic material is not well destroyed and there are changes.

For example, the same corn variety, in two different plots, the water and fertilizer conditions are different, the yield is also different, which cannot be inherited;

However, if an organism lives in an environment with high levels of radioactivity, it may cause changes in the source genetic material, which can be inherited.

a. The variation of living things is universal and is one of the characteristics of living things, and a is correct;

b. According to the cause of variation, it can be divided into heritable variation and non-heritable variation Variation caused by the change of genetic material is heritable, called heritable variation; Variation caused solely by the environment, if it does not affect the basis of Wu Feng's genetic material, is not inherited, it is called non-genetic variation, and B is wrong;

c. Variation can be divided into favorable and unfavorable variation from whether it is beneficial to the survival of the organism, and C is wrong;

d. Heritable variation is caused by changes in genetic material and can be passed on to offspring; Variation caused by environmental change, the genetic material has not changed, it is a variation that is not inherited, and cannot be passed on to offspring

Therefore, a

Heredity, in general, refers to the phenomenon that the traits of the parent are represented in the next generation. But in genetics, it refers to the phenomenon of passing genetic material from previous generations to offspring.

One of the attributes of a mutated biological organism, which manifests itself as a difference between parents and offspring. There are two types of variations, those that are heritable and those that are not. Modern genetics has shown that non-heritable variations have nothing to do with evolution, but rather heritable variations, which are due to changes in genetic material in the form of mutations and recombinations.

The environment may lead to variations, such as radiation, chemical pollution, microbial infection, etc., the environment determines whether the variation can be passed on from generation to generation (that is, the environment determines the direction of biological evolution), and it is also a process of screening genetic material by the environment, excluding unsuitable genetic sequences, so that organisms can evolve to what they are today.

Environmental factors are the factors that can cause biological variation, such as: physical factors: radiation, etc., chemical factors: biological factors, etc. It can cause them to have genetic mutations, chromosomal mutations, and so on.