Assume that a culture of e. coli was grown for approximately 50 generations in 15n (provided in the medium in the ammonium ion), which is a heavy isotope of nitrogen (14n). you extract the dna from the culture, and it has a density of 1.723 gm/cm3 (water = 1.00 gm/cm3). from the literature, you determine that dna containing only the common form of nitrogen, 14n, has a density of 1.700 gm/cm3. bacteria from the 15n culture were washed in buffer and transferred to 14n medium for one generation immediately after which the dna was extracted and its density determined.
(a) what would be the expected density of the extracted dna?
(b) after you heat the extracted dna until it completely denatures (95oc for 15 minutes), what would you expect the density of the dna in the denatured extract to be? for the purposes of this question, assume that dna has the same density regardless of whether it is single- or double-stranded.
(c) assuming that the molar percentage of adenine in the extracted dna was 20%, what would be the expected molar percentages of the other nitrogenous bases in this dna?
(d) assume that a fraction of the extracted dna was digested to completion with the enzyme snake venom diesterase. this enzyme cleaves between the phosphate and the 3' carbon. present a "simplified" diagram that would illustrate the structure of the predominant resulting molecule.

preservation because he preserves part of the land and preserves means save

explanation:

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.