Question
Cloning and Selective Breeding
Dolly the sheep was the first mammal cloned from a somatic cell (any body cell that is not a sperm or egg cell). This was done by removing the nucleus of an egg cell and replacing it with the nucleus of a somatic cell from the mammary gland of another sheep. The donor of the egg cell had a black face, while the donor of the somatic cell had a white face. Since Dolly had a white face, it was assumed that Dolly had the genetic makeup of the somatic cell donor. DNA testing verified that Dolly was, indeed, of the same genetic makeup as the somatic cell donor. Dolly had the identical genetic makeup of the somatic donor and did not share any genetics of the egg donor.
Another way that humans have been able to manipulate the characteristics of organisms is through artificial selection (selective breeding). Through selective breeding, different dog breeds are created with desired characteristics. One such dog is the English bulldog. Over the years, this animal has been bred to be larger and to appear more intimidating. However, because of the excess in selective breeding over many generations, today’s English bulldogs can suffer from a variety of health problems. In general, they have a high incidence of cancer, skin problems, arthritis, and will likely have a short life span.
Constructed Response Question
Does selective breeding increase or decrease the diversity of a species over time? Provide an explanation.
make it 3 sentences
Dolly the sheep was the first mammal cloned from a somatic cell (any body cell that is not a sperm or egg cell). This was done by removing the nucleus of an egg cell and replacing it with the nucleus of a somatic cell from the mammary gland of another sheep. The donor of the egg cell had a black face, while the donor of the somatic cell had a white face. Since Dolly had a white face, it was assumed that Dolly had the genetic makeup of the somatic cell donor. DNA testing verified that Dolly was, indeed, of the same genetic makeup as the somatic cell donor. Dolly had the identical genetic makeup of the somatic donor and did not share any genetics of the egg donor.
Another way that humans have been able to manipulate the characteristics of organisms is through artificial selection (selective breeding). Through selective breeding, different dog breeds are created with desired characteristics. One such dog is the English bulldog. Over the years, this animal has been bred to be larger and to appear more intimidating. However, because of the excess in selective breeding over many generations, today’s English bulldogs can suffer from a variety of health problems. In general, they have a high incidence of cancer, skin problems, arthritis, and will likely have a short life span.
Constructed Response Question
Does selective breeding increase or decrease the diversity of a species over time? Provide an explanation.
make it 3 sentences
Answers
Answered by
GPT-4o mini
Selective breeding decreases the diversity of a species over time by favoring specific traits and promoting the breeding of individuals that possess these desired characteristics. This practice can lead to a narrower gene pool, making the population more susceptible to genetic disorders and health issues, as seen in breeds like the English bulldog. Consequently, while selective breeding can enhance certain traits, it reduces overall genetic variation within the species.
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