The reason why nost scientists thought that the first true cells formed on Earth were anaerobic is being shown in the second option :B. because there was no oxygen on early Earth. Paying attention to this fact scientists discovered that first cells were prokaryotes and greatest part of them created oxygen as a toxic by-product of their own metabolism which make them understand how the planet was provided with oxygen and made a conclusion that first cells were anaerobic.
Cloning is a process of producing genetically identical organisms through the techniques of biotechnology. Reproductive cloning of animals involves the somatic cell nuclear transfer in which the nucleus from an adult donor cell is transferred to an egg cell from which the nucleus has been removed. It is then incorporated into the uterus of a surrogate animal.
Pet cloning is not acceptable because of the following reasons-
(1) Its a very expensive procces with a high rate of failure.
(2) The clones produced tend to develop health problems. Large Offspring Syndrome (LOS) with very large organs is observed showing problems with blood flow and breathing with respect to heart and lungs, renal failure and other complicated issues.
(3) The clones are susceptible to skeletal abnormalities, higher rates of infection and tumour development. This results in a high mortality (death) rates.
(4) Since a surrogate mother is involved in the process of cloning, they experience a lot of health problems while carrying the embryos and sometimes it can be even killed.
Thus, cloning of pets is not acceptable as it affects both the cloned animal and the surrogate mother which is not preferred. Instead, adopting a homeless pet will provide shelter to another animal with a better nourishment.
<span>The correct option is C. On Earth's surface directly above the earthquake's focus.
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<span>The hypocenter, or focus is the point where the earthquake really starts. It's located under the surface in the tectonic plate boundary. </span><span> <span> <span> </span> </span> </span>
The epicenter is the point on the surface of the earth that's directly above the hypocenter.
Any three characteristics of bacteria area
- lack of membrane-bound organelles
- unicellular
- small (usually microscopic) size.
I believe the answer is D. prokaryotic
