We wish to test if a certain vaccine developed for a disease is effective or not. What is the best way to do
this?

A
Vaccinate 100 animals
and expose all 100 to the
disease.
B
Vaccinate 100 animals
and expose 50 of them to
the disease.

C
Vaccinate 50 animals, do
not vaccinate 50 other
animals, and expose all
100 to the disease.

D
Vaccinate 50 animals, do
not vaccinate 50 other
animals, and expose the
vaccinated animals to the
disease.

The best way to test the effectiveness of a vaccine against a disease is vaccinate 50 animals, do  not vaccinate 50 other  animals, and expose all  100 to the disease (option C).

Explanation:

When testing a vaccine for effectiveness, the option is to administer the vaccine to half of the population exposed to a disease, since effectiveness should measure the performance of the vaccine within a community.

If there are 100 animals exposed to a disease, the fact that the 50 vaccinated animals do not get sick is an excellent test of how the vaccine works and what its effectiveness is.

The other 50 animals, not vaccinated, would act as a control group exposed to the same disease and sharing a certain space.

The other options are not correct because:

    A. Vaccinating the 100 exposed animals does not provide an unvaccinated control group to compare the effects of the vaccine.

    B. Vaccinating all 100 animals and exposing only 50 to the disease does not make sense, since it would not be possible to measure effectiveness in vaccinated animals that are not exposed.

    D. Vaccinating 50 animals and not vaccinating the other 50 to expose only the vaccinated animals to the disease does not make sense since the conditions of the test group and the control group should be the same.

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation: