After hundreds or even thousands of generations both alleles for sickle cell anemia are still common in those of African ancestry. This is supported by two mechanisms: heterozygote advantage and gene flow.
Heterozygote advantage
When an allele is said to be heterozygous, it is carrying one copy of a gene. For example if one carries a copy of sickle cell allele, it will stay in the population even after many generations — natural selection will not be able to remove it and it will be passed on through generations. So, having one copy of that allele is advantageous but not deleterious.
Gene flow
With humans migrating throughout the different parts of the world, sickle cell allele is passed from one person to another or in different populations. It is actually advantageous to have one copy of this allele especially if there’s malaria in the area, which the allele is resistant.
1.All living things are made up of one or more cells.
2.A cell is the most basic structure of organisms.
3.All living cells come from pre-existing cells.
Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
Hello!
The sentence that best describes what Colton discovers is D) The mass of the melted ice cube remained the same at 4 grams.
<h2>Why?</h2>
The melting of the ice cube is a physical process. That means that it is a process in which the identity of the substance (water) doesn't change, but only how their molecules are arranged.
In melting, a substance in the solid state changes to the liquid state. Its molecules go from having a definite volume and shape to having the same shape as the container that holds it, but there are no changes in the mass of the substance.
If the container is closed, Colton should record the same mass as the initial one, as mass doesn't change in physical processes.
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