Answer:
Some tumors are benign, which means they form in only one spot without spreading to surrounding tissue. Malignant tumors are cancerous and can spread to nearby tissue. As cancerous tumors grow, cancer cells can break off and travel throughout the body, forming new tumors.
Explanation:
Reintroduction of wildlife species means an attempt to resettle them within their historical area of distribution (within their range), where they have become extinct
Sex chromosomes determine one's gender. Of the 23 chromosomes humans have, one of the pairs are sex chromosomes. Autosomes make up 22 pairs of the chromosomes. They determine other traits of the body like hair color, eyes, or skin.
Answer:
This study was focused on an Ecosystem level, as it involved soil properties and above-ground vegetation interacting with mentioned soil physic properties.
Explanation:
Ecological studies can be performed at different hierarchy levels:
- <u>Organism</u>: This is an individual physiologically independent from other individuals. At this level, it must be understood <em>how an organism survives</em> under certain changing <em>physic and chemistry conditions</em>, and how it <em>behaves</em> to reproduce, avoid predators, and find food.
- <u>Population</u>: Groups of individuals from the same species, with similar characteristics, capable of crossing, leaving offspring that live in the same habitat at the same time. At this level, it is interesting to know the <em>size of the population required to leave fertile offspring</em> that ensure the population will <em>survive over time</em>. It is also interesting to know <em>genetic variability </em>that allows <em>evolutive adaptation </em>to environmental changes.
- <u>Community</u>: Relationship or interaction between different species groups that live in the same habitat and at the same time. At this level, it is interesting to study <em>inter-specific interactions</em> that could cause <em>changes in the populations´ size</em>. These could be the cases of competition, predation, parasitism, mutualism, and etcetera.
- <u>Ecosystem</u>: Basic interaction unit between population and environment that turn in complex relations existing between living and non-living elements in a given area. In the example, interactions between recovering vegetation and soil properties, as non-living elements.
Rossover is the first way that genes are shuffled to give rise to genetic diversity. Crossover takes place in sexual reproduction. Chromosomes line up side by side and break off pieces of themselves, then trade those pieces with each other. When they break at the same place (locus) in the sequence of base pairs, the result is an exchange of genes called genetic recombination. That is the normal way for crossover to occur. Genetic recombination ensures that the daughter cells produced have a different genetic makeup from the parent cell and thus diversity is created.<span>
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