Answer:
An energy pyramid is a model that shows the flow of energy from one trophic level to the next along a food chain. The pyramid base contains producers—organisms that make their own food from inorganic substances. All other organisms in the pyramid are consumers
Explanation:
Answer:
Natural selection can be described as a phenomenon in which individuals of a population which are better adapted to survive in an environment are favored by nature as compared to the individuals of the population which lack better characteristics to survive in the environment.
Through natural selection, evolution occurs and the allelic frequency changes over a period of time. The process of evolution as well as change in the allelic frequencies does not occur just by a single individual, rather it is a collective effort which takes a lot of time. Hence, we say that natural selection changes the population and not a single individual.
Answer:
<h3>Viruses can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own.</h3>
<h3>At the most basic level, viruses consist of genetic material contained within a protective protein coat called a capsid; the existence of both genetic material and protein distinguishes them from other virus-like particles such as prions and viroids.</h3>
<h3>They infect a wide variety of organisms: both eukaryotes (animals, fungi and plants) and prokaryotes (bacteria).</h3>
<h3>A virus that infects bacteria is known as a bacteriophage, often shortened to phage.</h3>
<h3>The study of viruses is known as virology, and those who study viruses are known as virologists.</h3><h3 /><h3>It has been argued extensively whether viruses are living organisms.</h3>
<h3>Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life.</h3>
<h3>They are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms.</h3>
<h3>A primary reason is that viruses do not possess a cell membrane or metabolise on their own - characteristics of all living organisms.</h3>
<h3>Examples of common human diseases caused by viruses include the common cold, the flu, chickenpox and cold sores.</h3>
One good reason would be that they could give someone, or many people who are in desperate need of a new organ, a second chance at life.
Answer:
C) parfocal.
Explanation:
A microscope can be defined as an optical device that is typically used to make an enlarged (magnified) image of a minute (small) object and as such reveals all the little information about the object that cannot be seen by the natural human eye.
A microscope is said to be parfocal if its lense is binocular and they can both be in focus.
Hence, if the objective lenses of a microscope can be changed without losing focus on the specimen, they are said to be parfocal.
