All viruses depend on cells for reproduction and metabolic processes. By themselves, viruses do not encode for all of the enzymes necessary for viral replication. But within a host cell, a virus can commandeer cellular machinery to produce more viral particles. Bacteriophages replicate only in the cytoplasm, since prokaryotic cells do not have a nucleus or organelles. In eukaryotic cells, most DNA viruses can replicate inside the nucleus, with an exception observed in the large DNA viruses, such as the poxviruses, that can replicate in the cytoplasm. RNA viruses that infect animal cells often replicate in the cytoplasm. so, the answer is A.
Answer:
The correct answer is - surface, proteins, and sugars.
Explanation:
Adhesins are the appendages present on the surface of the pathogen that help these pathogens to attach to the host cell and surface of the host. Adhesins are the components that are virulence factor these are present in both viruses and bacteria.
The adhesin component is generally made up of mainly of the proteins and sugars which help them to adhere to the cell of the host.
Thus, the correct answer is - surface, proteins, and sugars.
Answer:
Oxygen Depletion
Explanation:
In addition to the eutrophication of water bodies, wastewater effluents also contribute to another process of deoxygenation. The biological (bacterial) breakdown of organic solids in the effluent also consumes dissolved oxygen – the biological oxygen demand (BOD). In addition, the degradation of chemicals in the effluent removes oxygen from the water through chemical reactions – the chemical oxygen demand (COD).
As was previously mentioned, the loss of dissolved oxygen in the water can result in serious immediate, short-term, or long-term consequences to aquatic life. Fish survival is particularly affected by low oxygen levels. Decreased disease resistance, reduced growth, altered swimming behaviour, feeding, migration, and reproduction, increased threat of predation, and even rapid death are some of the effects of low dissolved oxygen concentrations.
Low oxygen levels can also alter the kinds of species present in the ecosystem. With a change in food supply, some populations of species decrease, while others increase. Fish such as whitefish, walleye, and pike may disappear, while bottom-feeding fish such as carp may increase in number.
