Here are the four postulates of natural selection, according to Charles Darwin:
1. variability - refers to different mutations that create different species
2. heritability - refers to the genes that are passed from one organism onto its descendants
3. overproduction of offspring - refers to the fact that more "children" is born than dies
4. natural selection - refers to those organisms that survive because they adapt to their surroundings better than those who will die
Crossover 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.
Answer:
C. Spinal cord
Explanation:
The brain communicates with the rest of the body by sending a signal with branches off the nerves in your spine
Answer and Explanation:
Organism
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Population
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Biological community
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Ecosystem
Ecosystem is a natural self-sustaining ecological unit in which the different types of habitats and their flora and fauna interact and influence one another. e.g., forest, grassland,lake
Biological community includes all the species-flora and fauna- that exist and interact in a habitat. For instance, the community in a montane forest includes all the animal species of mammals, reptiles, birds
Population is the total number of individuals of a particular species found in a habitat at a particular time.
Organism is any living thing in an ecosystem that has an organized structure, can respond to stimuli, reproduce, grow and develop.
