Unit 6 lesson 4 Inquiry and research
(1) Who was Gregor Mendel and what is his historical role in biology (specifically genetics)?
Gregor Mendel is often called the father of genetics. He pioneered his field by creating two important laws. The first was the law of segregation. The second was the law of independent assortment. Gregor Mendel is the founder of the science of genetics.
(2) Discuss Mendel’s laws of segregation and independent assortment.
The law of segregation states that there are two different types of traits for every characteristic in an organism. One of these is dominant and one is recessive. When an organism reproduces these two traits separate. The second law is the law of independent assortment. This law states that each characteristic is inherited independently. The first set of experiments looked at one trait at a time and the second set looked at multiple traits at a time. These experiments proved his laws in order respectively.
3) Explain how the events of meiosis I account for the observations that led Mendel to formulate these laws.
In meiosis I through cross hatching the genetic information of the daughter cells are mixed. Their DNA is different from the strands of DNA in their father cell. That is because during cross hatching the two strands of DNA in the father cell have individual amino acid sequences in each strand that switch over to the other strand as the two strands. This accounts for the different DNA. Of the daughter cells. This causes situations like P having purple petals, all four F1 having purple petals, but a flower in F2 having white petals. This is exactly what Mendel saw and what led him to formulate his laws.
(4) How do we know that an organism expressing a dominant trait is homozygous or heterozygous?
Well to start, homozygous means a pair of dominant or recessive traits and heterozygous means one recessive and one dominant trait. If we look at its offspring, and we find that his babies are given the dominant gene 100% of the time, that means the organism is homozygous with the dominant trait. If its babies are given the recessive gene at least 25% of the time, it means the organism is heterozygous.
(5) As a genetic counselor, you are asked to assess the risk for a couple with a family history of retinoblastoma who are thinking about having children. Both the husband and wife are phenotypically normal, but the husband has a sister with familial retinoblastoma in both eyes. What is the probability that this couple will have a child with retinoblastoma?
Because the sister of the husband has cancer, this means the husband must have at least one recessive gene. Assuming the wife has a recessive and dominant gene for cancer, there is a 25 % chance that the baby will develop cancer.
Gregor Mendel is often called the father of genetics. He pioneered his field by creating two important laws. The first was the law of segregation. The second was the law of independent assortment. Gregor Mendel is the founder of the science of genetics.
(2) Discuss Mendel’s laws of segregation and independent assortment.
The law of segregation states that there are two different types of traits for every characteristic in an organism. One of these is dominant and one is recessive. When an organism reproduces these two traits separate. The second law is the law of independent assortment. This law states that each characteristic is inherited independently. The first set of experiments looked at one trait at a time and the second set looked at multiple traits at a time. These experiments proved his laws in order respectively.
3) Explain how the events of meiosis I account for the observations that led Mendel to formulate these laws.
In meiosis I through cross hatching the genetic information of the daughter cells are mixed. Their DNA is different from the strands of DNA in their father cell. That is because during cross hatching the two strands of DNA in the father cell have individual amino acid sequences in each strand that switch over to the other strand as the two strands. This accounts for the different DNA. Of the daughter cells. This causes situations like P having purple petals, all four F1 having purple petals, but a flower in F2 having white petals. This is exactly what Mendel saw and what led him to formulate his laws.
(4) How do we know that an organism expressing a dominant trait is homozygous or heterozygous?
Well to start, homozygous means a pair of dominant or recessive traits and heterozygous means one recessive and one dominant trait. If we look at its offspring, and we find that his babies are given the dominant gene 100% of the time, that means the organism is homozygous with the dominant trait. If its babies are given the recessive gene at least 25% of the time, it means the organism is heterozygous.
(5) As a genetic counselor, you are asked to assess the risk for a couple with a family history of retinoblastoma who are thinking about having children. Both the husband and wife are phenotypically normal, but the husband has a sister with familial retinoblastoma in both eyes. What is the probability that this couple will have a child with retinoblastoma?
Because the sister of the husband has cancer, this means the husband must have at least one recessive gene. Assuming the wife has a recessive and dominant gene for cancer, there is a 25 % chance that the baby will develop cancer.