You have discovered a strain of mutant yeast cells that divides normally at 30°C but cannot enter M phase at 37°C. You determine that its mitotic cyclin and mitotic Cdk can form a normal M-Cdk complex at both temperatures. Which of the following temperature-sensitive mutations could NOT be responsible for the behavior at 37°C ? a. inactivation of an enzyme that ubiquitinates M cyclin b. inactivation of a protein kinase that acts on the mitotic Cdk kinase c. a decrease in the levels of a transcriptional regulator required for producing M cyclin d. inactivation of a phosphatase that acts on the mitotic Cdk kinase g

i would say it is

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.