Answer:
8900 CFU/mL
Explanation:
Colony Forming Units (CFU) is a value that indicates the degree of microbiological contamination of an environment. It expresses the relative number of microorganisms of a given taxon in a volume of one cubic meter of water.
UFC is the minimum number of separable cells on the surface, or inside, of a semi-solid agar medium that results in the development of a visible colony of the order of tens of millions of descending cells. The CFUs can be pairs, chains or clusters, as well as individual cells. Colony forming unit.
Calculation
Colonies * Dilution = CFU/mL
89 * (100/ 1 mL) = CFU/mL
8900 CFU/mL
Answer:
Thyroid hormones
Explanation:
Animals and people exposed to pesticides such as insecticides, fungicides, and herbicides, have shown to be affected by their effect on the thyroid. These chemicals can produce endocrine alterations acting as thyroid disrupters. They affect many mechanisms in the organisms such as inhibition of thyroid iodine uptake, <u><em>interference with the thyroid hormone receptor</em></u>, binding to transport proteins, among others. They cause toxicity in the functioning of the hypothalamic-pituitary-thyroid axis.
There are many studies that associate thyroid diseases with exposure to organochloride pesticides. Significant alteration in the TSH, T3, and T4 levels have been expressed by people directly or indirectly exposed to the chemicals.
An algal bloom has drained the lake of oxygen.
Explanation:
The possible cause of the fish death in the lake near the park is that an algal bloom has drained the lake of oxygen.
The green slime on top of the lake are the growing algae.
- This condition is caused by eutrophication.
- It occurs when nutrients are enriched in a water body causing the growth of algae.
- Algae bloom causes the depletion of oxygen levels in the ocean.
- They block off plants from producing oxygen and enriching water with it.
- Fishes need oxygen for their life actions.
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It's C! It changes as new evidence is found.
The correct options are as follows:
1. D.
Natural selection refers to the process by which living organisms that are more adapted to their environments usually survive and produce offspring that are like them. In the case of giraffes, the giraffes with the longest necks were able to survive in their environment and they reproduce offspring that are like them.
2. D
In the scientific world, scientists have open minds and they welcome all new ideas. These new ideas have to be tested to ensure that they are correct and superior to the facts that are already known. When a new hypothesis is put forward by a scientist, many scientists all over the world will test the hypothesis is order t confirm if it correct. If the hypothesis is found to be correct it will be accepted by all scientists.
3. A.
DNA test is a laboratory analysis that can be used to assess the level of relationship between living organisms. Related living organisms usually have some similar genes in their DNA, the level of closeness of these organisms will determine the quantity of similar genes that will be found in their DNA. Unrelated organisms on the other hand will have little or no similar genes in their DNA.
4. C.
The genetic code is the same across species, this fact points to the possibility that all living organisms originated from common ancestors. This support the evolution theory which stated that all living organisms descended from a common ancestor.
5. B.
Antibiotic drugs are usually effective against bacteria and other microbes, but the microbes can evolve and develop resistance to these drugs. Microbes are considered to have evolved when drugs that are used to inactivate them before no longer have any effect on them, thus they can easily survive in the presence of the drugs.
6. B.
If a particular specie of animal is able to avoid predators, it will increase in number more that those that are prey on by predators. The kings snakes were probably able to avoid predators, that is why, they were able to survive, reproduce offspring and increase in population in that particular ecosystem.
