Which of the following is an example of selective breeding?

All farm animals were created by......

• Farm animals are created by artificial selection or selective breeding.
• Like chicks, goats, camels, and pigs are raised to get products of commercial use like milk or meat.
• So, farmers want phenotypic traits in these animals like more milk production and more meat mass. 
• To get such phenotypic traits in animals they are bred with selective animals and this is called artificial selection. 
• For example variety of dogs were developed from wild wolves. 

Why is artificial selection important to understand evolution?

GMO stands for _____.

• GMO stands for genetically modified organisms.
• Such organisms have genetic material which is slightly different than their actual form.
• Human for some desired phenotypic characteristics in an organism manipulates their genes  (DNA or RNA).
• This manipulation is done on a molecular level by adding or deleting the part of DNA or RNA (gene) or sometimes by changing the structure of the gene. 

Artificial selection decreases diversity. This is a disadvantage because:

• When selective breeding is performed in plants or animals since a long time. The organisms of a population will have lesser diversity and more similarity.
• All the organisms of the population will have same traits as selective breeding is performed for this purpose (to achieve desirable characters which are beneficial for human.
• So, this process does not support evolution. There will not be variety in organisms.
• Varieties in organisms are required for them evolve.
• These variations help them to adapt in the environment and survive.
• Similar traits in organisms leads to the extinction of them.
• Also, selective breeding causes several health-related problems in animals.

In the process of selective breeding of food crops, what might a farmer look for?

• Selective breeding is performed to achieve desired characters in crops.
• A farmer wants to develop such variety of crops with high yields and good nutritional value. So, the crop should be producing large sized grains and more grains in quantity.
• So according to consumer's demand the farmer wants to produce a variety of crop which is disease resistant, to reduce loss in crop production.

Artificial selection is used to create fruits, vegetables, and animals.

• In the process of artificial selection, the two parental organisms are chosen with the traits of our choice, and when sexual reproduction is performed between them the produced offspring have desired characteristics from both parents.
• So, it is used since ancient times and a variety of fruits, vegetables, and domestic animals are developed from this.
• Different kind of broccoli is developed from wild mustard. 
• Seedless watermelons are successfully produced using this method.
• A variety of dogs are obtained by selective breeding of wolves.

Is Mule a hybrid.

• A mule is a hybrid.
• It is produced when sexual reproduction is performed between a horse and a donkey.
• So a horse and a donkey belong to different species. So they are distinctly related.
• Such offspring are often sterile.
• Mule has traits of both parents. Also it has more physical strength. 

Problems with animals that are selectively bred include:

• Selective breeding was developed in ancient times to get animal with desirable traits.
• But since a long time, selective breeding in animals has caused lesser variety and more similarities.
• Animals of a population are having same kind of traits according to human needs.
• This causes rare genetic disorders in animals. 
• The animal has lesser potential to survive.
• Along with beneficial traits some harmful traits can be passed to the next generation, so the animal may suffer from serious genetic disorder when harmful genes are expressed.

Inbreeding is when __________.

• When two closely related animals like having most of similar characters, from same species or same breed are bred together, this is called inbreeding.
• The produced offspring is homozygous. 
• Because both of the parents have same alleles at a locus. 

The purpose of selective breeding is to:

• For selective breeding human selects organisms having traits that are beneficial for them. 
• So to get these traits in just one organism, a cross is performed between the selected animals.
• This produced organism is having desirable traits and this is called artificial selection.
• Since ancient times human has produced domestic animals and crop plants through selective breeding.

Offspring produced from two different parent types, breeds, or species

• The offspring of two different parents that are from different breeds or species is called a hybrid. 
• Both parents of different types or breeds or species have different genetic compositions.
• They are having different alleles for their genes. 
• So as a result of sexual reproduction the produced offspring is having different alleles at the same loci for a gene. They are heterozygous.
• Also, these offspring have more new genetic combinations and thus more new traits.
• So, that's why these are called hybrids. 

Which of the following best represents inbreeding?

• The organisms which are closely related means have common ancestors and have many similarities in their genomes.
• Because of the same genes most of their traits are similar too.
• So, inbreeding represents crossing or sexual reproduction between similar animals.

Which of the following is NOT a result of selective breeding?

• Insects often match the color of the environment they live.
• This is a kind of adaptation.
• Matching with the color of the environment helps them to hide from the prey.
• So, this kind of change is developed only through natural selection.
• Because these traits help insects to survive.
• So this can not be a result of selective breeding.

Problems with selective breeding include:

• Selective breeding includes processes of inbreeding and hybridization.
• This causes lesser diversity in animals.
• The animals in a population have the same kind of traits and there will be a lack of variety.
• The animals will not be able to evolve.
• During natural selection, such changes or variations are developed in animal that helps them to survive in changing environments.
• But in the absence of natural selection, such variations will not develop and they won't be able to survive in changing conditions.
• So there will be health problems.

The image shows that the wolf is the ancestor to all the breeds of dogs shown below. How did this variation arise in a relatively short period of time?

• Through a selective breeding variety of dogs are developed from a common wolf ancestor.
• Through selective breeding or artificial selection, we can get new varieties in a short period as it is not a natural process.
• For the domestication of animals, such varieties are developed from wild varieties of animals.