Biology, 14.10.2019 19:30 Apple557

Agenetics question: tay-sachs disease is a rare human disease in which toxic substances accumulate in nerve cells. the recessive allele is inherited in a simple mendelian manner. a woman is planning to marry her first cousin, but the couple discovers that their shared grandfather's sister died in infancy of tay-sachs disease.

what is the probability that the cousins' first child will have tay-sachs disease, assuming that all people who marry into the family are homozygous normal?

i'll draw the pedigree i have and the work i've done - can't seem to get the right answer, though.

Answers: 2

Show answers

Answers

That was the picture, here is the math. Rather than computing all the individual probabilities then multiplying them out, I prefer to compute the probability distribution of each generation and pass it along that way.

The grandfather's probability of being Tt is 2/3. *If he is Tt* each of his offspring (2a and 2b) has a 1/2 probability of being Tt as well. So overall, the probability for each of his offspring being Tt is 2/3 * 1/2 = 1/3.

The offspring are independent events (one would hope) so the probability of both his offspring 2a and 2b being Tt is 1/3 * 1/3 = 1/9.

If 2a is Tt, 2a and TT spouse have a 1/2 probability of producing a Tt offspring. The same argument applies to 2b. The probability that 2a and 2b produce Tt offspring is 1/2 * 1/2 = 1/4. But the probability that 2a and 2b were Tt is 1/9 as calculated above. So the probability that 3a and 3b are both Tt is 1/4 * 1/9 = 1/36. So there is a 1/36 chance that 3a and 3b both are carriers.

If 3a and 3b have a child and if they are both Tt carriers, the probability that they will have a tt child is 1/4. The probability that 3a and 3b are both carriers is 1/36. So to obtain the probability of a tt child is 1/4 * 1/36 = 1/144.

I hope that this is the answer that you were looking for and it has helped you.

Answer from: Quest

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.

Answer from: Quest

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.

Another question on Biology

Biology, 22.06.2019 06:00

Monomers are the building blocks of larger molecules, called polymers. for example, proteins are composed of chains of amino acids that are linked together. cellulose is a polymer that makes up plant cell walls. cellulose is made from a chain of c6h10o5 molecules. which monomers are most likely used to produce cellulose? why?

Answers: 3

Answer

Biology, 22.06.2019 09:00

Dan made the table shown to describe two different relationships between animals. organism interactions relationship a relationship b one organism lives inside the organism it feeds off no organism is harmed which of the following statements is most likely correct?

Answers: 1

Answer

Biology, 22.06.2019 09:40

Me brainliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula.5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects.8. describe the planets’ orbits around the sun.9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets.13. what causes the seasons?

Answers: 1

Answer

Biology, 22.06.2019 10:00

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?

Answers: 2

Answer

You know the right answer?

Agenetics question: tay-sachs disease is a rare human disease in which toxic substances accumulate...

Questions