Definition:
Having two different alleles of a particular gene or genes.
(an Allele is a variant form of a gene.)
Simplification:
If the organism has one copy of two different alleles, it is heterozygous.
Eg: T and t
<em> </em><em> </em><em> </em><em> </em><em> </em><em>(</em><em>T</em><em> </em><em>for </em><em>tall</em><em> </em><em>and</em><em> </em><em>t</em><em> </em><em>for</em><em> </em><em>short</em><em>)</em>
Example:
<u><em>Pea</em><em> </em><em>Plants</em></u>
Pea plants can have red flowers and either be homozygous dominant (red-red), or heterozygous (red-white). If they have white flowers, then they are homozygous recessive (white-white). Carriers are always heterozygous.
A photograph of all the stained, prepared chromosomes in a eukaryotic cell is referred to as a karyotype
Physical - Sodium is solid at room temperature
Chemical - sodium is hydroscopic in nature
Answer:
Description below
Explanation:
Alcionaceans (Alcyonacea) is an order of corals that belongs to the subclass Octocorallia, of the Anthozoa class. <em>Soft corals</em> are commonly called, since they do not produce skeletons of calcium carbonate, so they do not contribute to the construction of the reefs, although they inhabit them.
The so-called soft corals and leather or leather corals, mostly meaty in appearance, have microscopic crystals of calcite in their tissues called spicules, whose function is to give consistency to the animal's tissue, in the absence of a skeleton. The shape and distribution of the spicules are the main characteristics used in the identification of genera and species of octocorals.
In addition to soft corals, this order includes gorgonians, which replace the skeleton of hard corals, Scleractinia order, by semi-rigid structures composed of calcite and / or a substance they generate called gorgonin.
Note about the question:
Statements are missing, and I failed to find the complete question. So here I give you some details about the theory that will help you to indetify the correct statement.
Answer and Explanation:
The endosymbiotic theory essentially states that some organelles of the eukaryotic cells, such as mitochondria and chloroplasts, were once free-living bacteria. Probably, these organisms must have been phagocytosed but not digested by another cell. On the contrary, these bacteria were able to adapt to their host in such a way that the two cells established a dependent relationship with each other.
It is speculated that chloroplasts derivate from cyanobacteria and that mitochondria derivate from rickettsias.
Cells would be beneficiated from this new bond, at the point that they could not survive by themselves anymore.
This theory is supported by a few characteristics of the chloroplasts and mitochondria that suggest that they once were a free cell. For example,
- Both organelles present their genetic material. This DNI is independent of the cell´s DNA, is bi-catenary and circular, identical to the bacterial DNA, and very different from the one of the eukaryotic cells.
- These organelles do not divide by mitosis. Instead, they do it by binary fission and are capable of synthesizing their ribosomes and organelles.
- Both organelles present a double membrane, a characteristic that reinforces the idea of being phagocyted. The internal membrane looks identical to the bacteria membrane, while the external membrane looks like the eukaryotic one.
- In fact, in this internal membrane are placed the energy centers, exactly as it occurs in bacterias membrane.
- Finally, the sizes of the organelles are similar to the size of some procaryotes.
