Question

Question 6

1. A person can be a “carrier” of sickle cell but not have the disease. How is this possible?

1 points

Question 7

1. Scientists James Watson and Francis Crick determined the double helix structure of DNA. Why is that structure important in DNA replication?

   	A.	When the DNA separates into two halves during replication, each half is a mirror image of the other, so the new halves fit right back together again in the new cell.
   	B.	The structure is like a ladder, so it's easy for new cellular material to “climb” the ladder to reform in a new cell.
   	C.	When the cell splits, the DNA is twisted together, so it doesn't easily come apart during replication.
   	D.	Because each base can only pair with a particular other base, even when the DNA splits, the bases will always match up the same way as it reforms.
   	E.	Because DNA is double, it's already evenly split, so it ends up being the same in every replicated cell.

1 points

Question 8

1. Mutations can be the result of environmental factors like exposure to X-rays or carcinogens.

   	A.	False
   	B.	True

1 points

Question 9

1. If you investigate and map out the family history of a particular trait, what have you produced?

1 points

Question 10

1. Why don't Mendel's rules entirely explain heredity patterns?

   	A.	Genes can have random effects.
   	B.	Gene interaction and the environment can alter the patterns.
   	C.	No two alleles work the same way.
   	D.	There are many more genes in humans than in peas.
   	E.	Plant genetics work differently than human genetics.

1 points

Question 11

1. In Mendel's initial experiment with peas, why doesn't the flower color white show up in the first generation (after the first cross of white with purple parents)?

1 points

Question 12

1. When one base in a DNA strand is replaced with another, what type of mutation is this?

   	A.	Translocation
   	B.	Point mutation
   	C.	Duplication
   	D.	Inversion
   	E.	Deletion

Answer 1

6) Sickle cell anemia is a recessive disease so for an individual to be affected with the disease both the alleles have to be mutated, so a heterozygous individual is not affected and can be a carrier that is a heterozygous individual can pass mutated alleles to offspring. so a person can be a “carrier” of the sickle cell but not have the disease.

7) according to Watson and Crick DNA is a double helix in which 2 DNA strands are linked together via hydrogen bonding between the nitrogen bases, that is due to basepairing so the answer is D) Because each base can only pair with a particular other base, even when the DNA splits, the bases will always match up the same way as it reforms.

8) mutations can be caused by mutagens, carcinogens are a class of mutagens, X-rays, gamma rays are mutagens, so the statement is True.

Answer 2

6) Sickle cell anemia is a recessive disease so for an individual to be affected with the disease both the alleles have to be mutated, so a heterozygous individual is not affected and can be a carrier that is a heterozygous individual can pass mutated alleles to offspring. so a person can be a “carrier” of the sickle cell but not have the disease.

7) according to Watson and Crick DNA is a double helix in which 2 DNA strands are linked together via hydrogen bonding between the nitrogen bases, that is due to basepairing so the answer is D) Because each base can only pair with a particular other base, even when the DNA splits, the bases will always match up the same way as it reforms.

8) mutations can be caused by mutagens, carcinogens are a class of mutagens, X-rays, gamma rays are mutagens, so the statement is True.