Viruses are not considered "alive" because they lack many of the properties that scientists associate with living organisms. Primarily, they lack the ability to reproduce without the aid of a host cell, and don't use the typical cell- division approach to replication.
Answer:
4. The suspected causative agent must be isolated from the diseased host and grown in pure culture
Explanation:
Robert Koch (1843-1910) was one of the most important bacteriologists of all time. Famous for discovering the tuberculosis bacillus (precisely on March 24, such as today, in 1882), he also discovered the cholera bacillus and is considered the founder of bacteriology. He worked on the isolation of infectious agents and reinfections from pure cultures, experiences from which he established the "Koch Postulates".
These postulates have been taken as a reference that describes the etiology of all the causative agents of an infectious disease, although they were originally used to describe only the tuberculosis bacillus. They are the following:
1- The agent must be present in each case of the disease and absent in the healthy.
2- The agent should not appear in other diseases.
3- The agent must be isolated in a pure culture from the lesions of the disease.
4- The agent has to cause the disease in an animal that can be inoculated
Answer:
kinetic energy is a energy of motion. At a given temperature, individual particles of a substance have a range of kinetic energies. The motion of particles theoretically ceases at absolute zero.
Answer:
A cladogram is a diagram used to represent a hypothetical relationship between groups of animals, called a phylogeny. A cladogram is used by a scientist studying phylogenetic systematics to visualize the groups of organisms being compared, how they are related, and their most common ancestors.
Answer:
Explanation:
Straight wings are dominant over curved wings
Let Straight wings : H
curved wings : t
smooth eyes are dominant to sparkling eyes
let smooth eyes = H
spark ling eyes = t
tan body is dominant to ebony body color.
Again; Let tan body color be H
Let ebony color be t
If flies that are heterozygous for all three traits are crossed;
we have HtHtHt × HtHtHt
Then the selected trihybrid traits for the cross will be (HHH,HHt, HtH, Htt, tHH, tHt, ttH, ttt)
We will realize that from the punnet square in the diagram below, the proportion of the offspring would you expect to be heterozygous for all three traits (i.e HtHtHt) is asterisk in the punnet square and will be 
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