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B6: Quiz 10 – Answers
B6: Quiz 10 – Answers
1) We choose two organisms that have desirable characteristics. We then breed them with each other which results in a variety of offspring with a range of characteristics. We then choose the best offspring and breed from them. This selection and breeding process repeats itself over and over again, which leads to the desirable characteristics becoming stronger in the population.
2) We choose two dogs that have desirable characteristics; we would choose a dog that is very intelligent and a dog that has a very strong bite. This creates a variety of offspring all with different amounts of desired characteristics (some will be very intelligent and have a strong bite, some will be very intelligent and have a weak bite, some will have a strong bite and be stupid, and some will have a weak bite and be stupid). We then choose the best offspring (strong bite and intelligent) and rebreed them. This selection and breeding process repeats itself over and over again, which results in a dog breed that is very intelligent and has a strong bite.
3)
a) A reduction in the gene pool happens because we are breeding organisms that have genes that are very closely related to one another. This results in less variety of genes in a selectively bred population compared to an unselectively bred population.
b) The two negatives are:
2) We choose two dogs that have desirable characteristics; we would choose a dog that is very intelligent and a dog that has a very strong bite. This creates a variety of offspring all with different amounts of desired characteristics (some will be very intelligent and have a strong bite, some will be very intelligent and have a weak bite, some will have a strong bite and be stupid, and some will have a weak bite and be stupid). We then choose the best offspring (strong bite and intelligent) and rebreed them. This selection and breeding process repeats itself over and over again, which results in a dog breed that is very intelligent and has a strong bite.
3)
a) A reduction in the gene pool happens because we are breeding organisms that have genes that are very closely related to one another. This results in less variety of genes in a selectively bred population compared to an unselectively bred population.
b) The two negatives are:
- There may be an increase in the number of genetic conditions/ disorders in the population. This is because a small gene pool means that there is a greater chance of offspring inheriting harmful genetic alleles, thus meaning that there is an increased chance of developing genetic conditions
- A high proportion of the population may be killed or affected by a certain disease. This is because all of the offspring have genes that are very similar to each other, so if one of the offspring is killed by the disease, it is likely that all of the other offspring will also be killed by the disease. This is because there is less chance of any resistant alleles being present in a selectively bred population with genes that are very closely related to one another
Questions
1) Describe the basic steps/ process for selective breeding.
2) A dog breeder wants to selectively breed his dogs so that they are extremely intelligent (can be trained easily) and have a strong bite. Describe the process that he can undertake to selectively breed his dogs.
3) Selective breeding can result in a reduction in the gene pool.
a) Why does selective breeding result in a reduction in the gene pool.
b) Give two negatives of a reduction in the gene pool. Explain your negatives.
1) Describe the basic steps/ process for selective breeding.
2) A dog breeder wants to selectively breed his dogs so that they are extremely intelligent (can be trained easily) and have a strong bite. Describe the process that he can undertake to selectively breed his dogs.
3) Selective breeding can result in a reduction in the gene pool.
a) Why does selective breeding result in a reduction in the gene pool.
b) Give two negatives of a reduction in the gene pool. Explain your negatives.