Answer:
Australia has large amounts of sandstone and silica.
and
Opal can only be formed where an ocean comes in contact with land.
Explanation:
because it needs standstone and a ocean to be able to create opal
Answer:
Due to stomata.
Explanation:
Transpiration occurs mainly through leaves because of the presence of stomata n the lower side of the leaves. Transpiration refers to the loss of water from the body of plants so leaves has small pores which is used by the plant to regulate internal temperature. Sunken stomata lower the rate of transpiration because it is not directly exposed to the surface which protects the escaping water vapor due to air.
Answer:
The correct answer is option 4.
Explanation:
Viruses cannot be considered alive as they cannot carry out metabolic reactions on their own. Metabolism signifies the tendency to gather and use energy. The chemical reactions in the cells spontaneously change the molecules into the forms of energy, which can be utilized by the organism.
However, in the case of viruses, they are too small and simple to collect and utilize their own energy. They are completely dependent upon the host cells for energy. The viruses only require energy when they need to make duplicates of themselves, however, they do not require any energy when they are present outside of the cell. Thus, as they cannot carry out metabolic reactions, they are not considered as living.
Answer:
A. The lytic lifecycle allows viruses to reproduce more quickly but also kills the host and forces the virus to find a new host cell.
Explanation:
The lytic lifestyle of the viruses (e.g. bacteriophage) can be described through the next steps:
- attachment and injection into the host cell (e.g.bacterial cell)
- synthesis of the early virus proteins which break down host's DNA
- virus uses host's machinery (for the replication, transcription and translation) to produce the rest of its proteins and to form new virus particles.
- host cell burst and many new virus particles are released.
During the lysogenic cycle, virus does not kill the host. It integrated its DNA into host's genome and stays dormant until conditions are optimal for reproduction.