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.
Answer:
A woman creates new immature ova in the ovary each time she has a menstrual cycle.
Explanation:
During the menstrual cycle, hormones present in the body make the immature eggs 'mature' ones, in the ovary. About in half of the cycle, hormones make the release of the mature egg from the ovary and travels towards uterus. It can remain there for 24 hours and if not fertilized the it breaks down and released out.
Answer:
E) horizontal gene transfer
Explanation:
Horizontal gene transfer(HGT) is mainly seen in bacteria. Bacteria exchange their genetic material from the horizontal gene transfer method. There are three methods in HGT- conjugation, transduction, and transformation.
In conjugation, the bacteria exchange their plasmid through sex pilus. In transformation, bacteria take up other's genetic material from its environment and in transduction virus-mediated gene transfer occurs.
Therefore in bacteria and nucleus, the genetic material exchange can occur only through HGT.
Answer:
Yes.
Explanation:
In the tropical Pacific, like the western coast of central and south America, the surface of the sea is cooler than normal and that results in reduced rainfall, drought and increased fires. This definitely brings about a negative effect on wildlife, as there is less water and food available.
However, in South East Asia, a higher than normal rainfall is commonly experienced, which is good for agriculture.
