<span>The current estimated total number of species on earth is between five million and hundred million.
The reason why it is hard to get an accurate count is because some species are very hard to find reason being that of nocturnal habits, location, and the size.
All the species which have ever lived on earth are being estimated to be extinct. It is approximately one extinction for every million species for years. Mammals species like typically persist for one million years.</span>
Answer:
Option D is correct
Explanation:
Gradient elution of transcription factor is facilitated by disrupting DNA- transcription factor interaction by increasing concentration of salt in other to increase the ionic strength.
1A): Fats are =====> <u>Solid at Room temperature</u>
1B): Oils are =====> Liquid at Room Temperature
2A): Lipids ====> <u>Are a group of organic compounds, that include fats, oils, waxes and related substances. Lipids are composed of carbon and hydrogen, and oxygen, but there is no definite ratio of hydrogen to oxygen atoms lipids as there is in carbohydrates. Simple lipids, which are the most common type, are made up of three fatty acids molecules, and glycerol molecule.</u>
2B): Carbohydrates =====> <u>Are organic compounds composed of carbon, and hydrogen, and oxygen. The proportion of hydrogen atoms to oxygen atoms in carbohydrates is the same as in water; Two hydrogens to one oxygen. There are three basic types of carbohydrates. Monosaccharides, disaccharides, and polysaccharides.</u>
3): <u>A positive control ===> s</u><u>hould give the desired outcome of the experiment, provided that all the reagents and equipment are functioning properly. For example, if your experiment results in the ability of bacteria to grow on a petri plate containing antibiotic, your positive control will be bacteria that are known to carry the appropriate drug resistance marker. Even if none of your experimental bacteria grow, as long as there is growth of the positive control you know that growth was possible. </u>
3B): A Positive Control =====> <u>should be designed to not give the desired outcome of the experiment. In the example above, bacteria which do not carry a drug resistance marker should not be able to grow on a petri plate containing antibiotic. If growth is observed, it is a red flag that something is wrong with the experiment.</u>
Hope that helps!!! : )
1. Griffith in his experiment used two related strains of bacteria (Streptococcus pneumonia), known as R and S and mice, trying to develop a vaccine against pneumonia. R strain-formed nonvirulent, rough-edged colonies
S strain- rounded and smooth colonies, with sugar protection coat, virulent
Mice that were injected with S strain developed pneumonia and died.
But, when mice were injected with heat-killed S strain it did not cause disease in mice.
The next part of experiment is the injection of combined harmless R bacteria with harmless heat-killed S bacteria. The result was that the mouse developed pnenumonia and in blood sample from the dead mouse, living S bacteria were found.
2. From his experiment, Griffith concluded that injected together, R strain and S strain bacteria most likely “communicate”. The R-strain bacteria took "transforming principle" (we know today that this is genetic material DNA) from the heat-killed S bacteria which allowed them to "transform" into virulent bacteria.
Answer:
Which phrase defines a community?
<u>group of the same species that live together</u>
Explanation:
as community means where same character animals used to live