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SVEN [57.7K]
2 years ago
7

Identify which two of Koch's postulates would most likely not be fulfilled when trying to link a human virus to a particular dis

ease. Choose one or more: A. The microbe is found in all cases of the disease but is absent from healthy individuals. B. The microbe is isolated from the diseased host and grown in pure culture. C. When the microbe is introduced into a healthy, nonhuman experimental host, the same disease occurs. D. The same strain of microbe is obtained from a newly diseased host.
Biology
1 answer:
hammer [34]2 years ago
3 0

Answer:

 A) & B)

Explanation:

A) There are certain viruses that are present in both healthy and disease people.

Example: Polio virus is found in many human but it causes disesease in only 1% of human.

B) Viruses require host machinery for replication so they may not replicate in pure culture.

The postulate C is also violated, the virus may not produce disease in non-human experimental host because of inappropriate animal or vaccinated animal etc. Others exception includes, the same disease may be caused by various organisms and different organisms can also cause the same disease.

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Which of the following describes how the amount of available energy changes from one trophic level to another? A) Available ener
Mekhanik [1.2K]

Answer:

B) Available energy decreases as trophic levels increase.

Explanation:

Each time an organism consumes energy, it absorbs it. When it dies the energy is released and only some of it is consumed the organism that eats the first organism. This continues and by the end there is very little energy left because most of it was released into the world.

5 0
3 years ago
The newly-discovered organism Yawle nhoj, has a diploid chromosome number of 56. Suppose that one of the chromosome pairs fails
max2010maxim [7]

Answer:

The correct answer will be 2 gametes with 29 chromosomes and 2 gametes with 27 chromosomes will be formed.

Explanation:

Meiosis is a type of cell division which produces four daughter cells. Chromosomes separate or the disjunction of chromosomes takes place during anaphase I and anaphase II of meiosis I and II respectively.

If a chromosome fails to disjoin at meiosis I this will result in the production of four gametes with an unequal number of chromosomes. Out of four gametes, 2 gametes produced will be trisomic gametes that are with one additional copy of chromosome and 2 gametes will be monosomic with one less number of chromosome.  It means the trisomic gametes will have 29 chromosomes while 2 monosomic gametes will have 27 chromosomes.

Thus, 2 gametes with 29 chromosomes and 2 gametes with 27 chromosomes will be formed is the correct answer.

4 0
3 years ago
DNA evidence analysis is an imperfect science. Provide two reasons why this may
HACTEHA [7]

Answer:

Explanation:

Imperfect science can be described as the scientific study of a research/field that is not complete or is characterized with a number of faults. While there are many scientific research fields or focus that fall under this category (because scientists are constantly seeking to improve existing knowledge of various scientific field), let's limit our scope to DNA evidence analysis.

DNA evidence testing for instance is very expensive which makes it difficult (in most cases) for victims to request for it in cases of crime (except requested by the government). For instance, if a killing that involves a struggle was done in a small neighborhood of about a 100 people with no visual confirmation of the killer but just some blood samples of the killer, DNA evidence testing might still not be used in a case like this despite the  crime happening in a relatively small community.

Also, since DNA evidence testing relies on the gene and there is a lot of research going on at the moment on genes (including gene mapping and locus system) which can assist to lower the number of suspects by predicting the origins of suspects. It should be noted that reducing the number of suspects reduces the amount that will be spent on DNA analysis of the suspects (since there are fewer suspects).

4 0
2 years ago
What do adenine, ctyosine, guanine, thymine, and uracil have in common
Goshia [24]

Adenine and guanine have a fused-ring skeletal structure derived of purine, hence they are called purine bases. ... Similarly, the simple-ring structure of cytosine, uracil, and thymine is derived of pyrimidine, so those three bases are called the pyrimidine bases.

8 0
2 years ago
What is the definition is Heterogeneous?
rjkz [21]

Answer:

Heterogeneous consists of the structure with various components or elements appearing to be irregular or variegated.

Explanation:

An example of this definition is a dermoid cyst in which has the components of a heterogeneous attenuation on CT.

4 0
2 years ago
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