Answer:
Option-A
Explanation:
Penicillin is an antibiotic drug that is derived from the fungal species of Penicillium molds especially the<em> Penicillium notatum</em>. The penicillin acts by disrupting the formation of the cell wall and thus prevents the growth of the bacteria.
The discovery of penicillin was accidental when he was studying the petridish of staphylococcus and he found that due to avoidance while the experiment, molds grew in the petridish. The area around the mold was clear and clear rings without the bacteria were easily observed. This lead to the discovery of the penicillin compound.
Thus, Option-A is the correct answer.
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. Karyotypes also describe the chromosomes count of an organism and the appearance of these chromosomes under the microscope. Cell which lack cell cycle control are often cancerous cells and they look different under the microscope compared to the normal cells. Cancerous cells will look different under the microscope in term of number of chromosomes, size, length, positioning and general appearance.
Answer:
D. Nitrogen-14 has 7 electrons, 7 protons, 7 neutrons nitrogen-15 has 7 electrons, 7 protons, and 8 neutrons
Explanation:
In an atom, number of electrons is equal to the number of protons. And the number of neutrons is equal to the difference between the mass number of the atom and the atomic number. For Nitrogen 14, electron is 7, proton is also 7 as number of electrons and number of protons are equal. So, the neutron will be 14-7= 7. For Nitrogen 15, electron number is 7 so proton number will be also 7. Neutron number for nitrogen 15 will be 15-7= 8. That's why the answer is option number 4.
