Which organism would make a good bioindicator?

You are studying a biochemical pathway in the mold Neurospora where enzyme 1 converts the initial substrate into intermediate su

solmaris [256]

Complete question:

You are studying a biochemical pathway in the mold Neurospora where enzyme 1 converts the initial substrate into intermediate substrate A; enzyme 2 converts intermediate substrate A into intermediate substrate B; enzyme 3 converts intermediate substrate B into intermediate substrate C; and enzyme 4 converts intermediate substrate C into the end product, an amino acid that is essential for growth. You isolate a mutant that is unable to grow on minimal media. Which data would provide the strongest support for the hypothesis that this mutation occurred in the gene that codes for enzyme 2?

a. The mold can grow on rich medium plus intermediate substrate C, but not on rich medium plus intermediate substrate B.

b. The mold can grow on minimal medium plus intermediate substrate B, but not on minimal medium plus the initial substrate.

c. The mold can grow on minimal medium plus intermediate substrate B, but not on minimal medium plus intermediate substrate A.

d. The mold can grow on rich medium plus intermediate substrate D, but not on rich medium plus intermediate substrate C.

e. The mold can grow on minimal medium plus intermediate substrate A, but not on minimal medium plus intermediate substrate C.

Answer:

c. The mold can grow on minimal medium plus intermediate substrate B, but not on minimal medium plus intermediate substrate A.

Explanation:

Let us first diagram the pathway for a better understanding.

The normal organism produces four enzymes that convert substrates in the medium that allow it to survive, grow, and reproduce.

initial substrate ------------> A ----------------> B ----------------> C ----------------> AA

Enzyme 1 Enzyme 2 Enzyme 3 Enzyme 4

Any mutation on the Neurospora´s enzymes will not let the organism grow on the minimal medium because it will not be able to convert the minimal substrate into the following one, because the mutated enzyme will not accomplish its original function.

So if the mutation occurs in enzyme 1, the organism will not be able to convert the initial substrate into intermediate substrate A. And the rest of the reaction will not be possible either because of the lack of substance A.

initial substrate -----X----> A -------X-----> B ------X--------> C ------X-------> AA

mutated Enzyme 1  Enzyme 2 Enzyme 3 Enzyme 4

If the mutation occurs in enzyme 2, the organism will not be able to convert the intermediate substrate A into intermediate substrate B. And the rest of the reaction will not be possible either because of the lack of substance B.

initial substrate ------------> A -------X--------> B -------X------> C --------X-----> AA

Enzyme 1 mutated Enz. 2 Enzyme 3 Enzyme 4

If the mutation occurs in enzyme 3, the organism will not be able to convert the intermediate substrate B into intermediate substrate C. And the last reaction will not be possible either because of the lack of substance C.

initial substrate ------------> A ----------------> B -------X--------> C -------X------> AA

Enzyme 1 Enzyme 2 mutated Enz. 3 Enzyme 4

And if the mutation occurs in enzyme 4, the organism will not be able to convert the intermediate substrate C into the essential amino acid.

initial substrate ------------> A ----------------> B ----------------> C -------X-------> AA

Enzyme 1 Enzyme 2 Enzyme 3 Mutated Enz. 4

But, if we artificially add to the medium the substrate that should be produced by the original enzyme (and that is not converted because of the mutation), then the organism will grow and survive because the other enzymes will be able to produce the essential amino acid.

So, if enzyme 2 is the only enzyme mutated, the organism will not be able to live in a medium with substrate A because the mutated enzyme will not convert the substrate A into B. There will not be B substrate in the medium, and the other enzymes will not produce the essential amino acid. So if the mutation occurs in enzyme 2, substrate A is useless to the organism because it will not survive.

But if we add the intermediate substrate B to the medium, the organism will survive. In a medium with substrate B, all the other reactions will be possible, and the organism will get the essential amino acid. The artificial addition of B substrate will replace the function of the original enzyme 2 -which is the one that converts A into B-.

3 0

3 years ago

The fusiform face area (ffa) in the brain is often damaged in patients with

serious [3.7K]

Muscle spasmsHypocalcemia can cause

emotional disturbances
depression of the nervous system
muscle weakness
sluggish reflexes
muscle spasms

6 0

3 years ago

What is the fitness of an organism?

max2010maxim [7]

Answer:the fitness of an organism is the ability to survive and reproduce

Explanation:

7 0

3 years ago

Explain incomplete dominance, using snapdragon flowers as an example.

oee [108]

Answer:

Dominant allele does not completely conceal recessive allele.

Snapdragon with genotype Rr (R being red and r being white), would have a phenotype of pink flowers.

Explanation:

Incomplete dominance is where a dominant allele is not able to completely conceal a recessive allele, usually leading to a phenotype which appears to be a combination of the two.

For example, in snapdragons:

The allele for red flowers (R) is dominant over the allele for white flowers (r). Let's say a snapdragon flower had the genotype Rr, one allele for red flowers and one for white. In the case of 'normal' dominance the dominant red flower allele (R) would mask the effects of the recessive white flower allele (r), resulting in the phenotype (outward observable characteristics) of having red flowers.

However here in the case of incomplete dominance, the dominant allele would not be able to fully cover up the effects of the white flower allele, meaning that both colors (red and white) are expressed in the phenotype, resulting in pink flowers.

Hope this helped!

5 0

3 years ago

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If 84 J of work are exerted to pull a wagon, how much force does it take to pull the wagon 7.0 m? Round your answer to the neare

nirvana33 [79]

Work is said to be done when an object moves due to a force applied. Work is calculated by multiplying the force applied and the distance traveled due to the force. It is expressed as:

W = Force x distance

W = 84 J = F (7.0 m)
F = 12 N

Hope this answers the question.

6 0

3 years ago

Read 2 more answers