Answer:
Crossing over increases the genetic variation
Errors in crossover formation result in chromosomal rearrangements (duplications and deletions) and may also cause chromosome nondisjunction
Explanation:
Crossing over, also known as recombination, refers to the exchange of genetic material (DNA) between non-sister chromatids of homologous chromosomes during meiosis. Crossing over increases the genetic variation of the resulting gametes, allowing different genetic combinations to be passed from parents to offspring. Unequal crossing over is a type of error associated with chromosomal duplication and/or deletion events. Unequal crossing over occurs when homologous sequences are not paired precisely. Moreover, errors in crossing over may also cause chromosome nondisjunction, thereby leading to aneuploidies.
Answer:
Miasma theory was replaced because John Snow collected data that showed that germs cause disease.
Explanation:
The theory of miasma was proposed in the past when some scientists —like doctors Thomas Sydenham and Giovanni Maria Lancisi— thought that disease was the product of emanations originated by the decomposition of organic matter. This theory was based on the fact that diseases predominated in places with poor hygienic conditions.
John Snow, an english physician, was one of the main contributors to the <u>microbial theory of disease</u>. In 1854, while a cholera epidemic was occurring, he collected data and organized it statistically and then concluded that the disease was caused by germs present in drinking water. This <u>data was contrary to the miasma theory, which would eventually be displaced by the microbial theory of the disease</u>.
This question is incomplete as the specific food chain is not provided. In general, a food chain will have a primary producer at the base of the chain. This is an organism that is able to utilise a form of energy to convert carbon dioxide in the atmosphere to a carbohydrate. For terrestrial food chains, these are typically plants, who by utilising the energy from the sun, are able to convert carbon dioxide to carbohydrates. The subsequent level in the food chain may be a primary consumer, typically herbivores, that consume plant matter. Subsequent links in the chain would typically be secondary consumers, who would be carnivores, omnivores or decomposers. Carnivores would typically be predators and would be at the apex of the food chain. Energy is lost from one link to the subsequent link in the food chain, through basic respiration and inefficient energy transfer from one link to another. This explains why more resources (land, water and air) are required to grow meat rather than plant matter. More of the sun's energy is available within the lower trophic levels in a food chain, before much of it is lost as energy moves up the food chain. An easy example to illustrate this is that much of the livestock raised in the USA is fed grain. If people rather ate the grain than the livestock, they could obtain all their required energy from a smaller amount of grain then would be needed to raise the meat they require.
Answer:
organism,species,community
<em>hop</em><em>e</em><em> this</em><em> answer</em><em> </em><em>correct</em><em> </em><em>(</em><em>^</em><em>^</em><em>)</em>
Answer:
Somatic cells use mitosis
Explanation:
somatic cells are body cells or skin cells
