Answer:
c) Negri bodies are a diagnostic sign of Rabies virus infection.
Explanation:
Rabies is an infection caused by rabies virus which affects the neurons and causes inflammation of the brain. It is a deadly disease and many animals are carriers of this disease like dogs, cats, raccoons, wolf, bats, fox, etc.
It is diagnosed by the presence of Negri bodies in the cytoplasm of nerve cells. Negri bodies are inclusions that are round or oval shapes having a size between 0.25 to 27 μm. Negri bodies can be frequently diagnosed in Purkinje cells of the cerebellum and pyramidal cells of Ammon’s horn.
Apart from these cells, they can be found in various ganglia, neurons of the tongue and other organs. So the correct answer is c.
Answer:
The plants in an ecosystem produce food for most of the other organisras that live in that ecosystem. The role of a plant in its ecosystem is its <em>trophic level</em>
Explanation:
Plants are the least to be found in the trophic level, they are otherwisely called <em>autotrophs. </em>They make food for themselves while others among the trophic level depend on them
Answer:
Alternative splicing
Explanation:
One gene can lead to multiple proteins by the alternative splicing of the mRNA. The alternative splicing is the most common process that contributes to protein diversity at a pot-transcriptional level. This process is carried out by different combinations of including or excluding exons of the mRNA, obtaining proteins that differ in their amino acids sequence, consequently having different biological functions.
Answer:
Reproductive isolation refers to the inability of an organism or species to breed successfully with other organism or species.
It may arise from various factors such as:
- Geographical isolation such as river, mountain, etc
- Behavioral changes such as mating time or season, mating rituals, mating location etc.
- Physiological differences such as change in shape of sex organs which causes lack of fit between copulatory organs.
- Genetic differences.
Reproductive and geographical isolations between two populations (of same species) inhibit the flow of genes among them. Slowly, these isolations increase the variations in the gene pools of the two populations.
These genetic variations keep on increasing with time. In addition, as an adaptation to their surrounding or habitat the two populations would develop different behavioral and physiological changes
With time, these differences will increase up to such an extent that the two populations would not be able breed with each other. Hence, it would lead to the evolution of one or both the populations into new species.
