I would say A, B D are the correct answers
The Earth is around 4.6 billion years old. Earth has a slightly squashed sphere, measuring 7,973 miles (12,756 km) in the diameter at the equator.
If they were to be no separation <span>of a pair of chromosomes during meiosis resulting in formation of a sperm or ovum with 24 chromosomes instead of 23.</span>
Breaking cells open to release the DNA.
Separating DNA from proteins and other cellular debris.
Precipitating the DNA with an alcohol.
Cleaning the DNA.
Confirming the presence and quality of the DNA.
Answer:
Answer is C. Bacteria
Certain types of bacteria have a relationship with certain plants where they help convert nitrogen into a usable form.
Explanation:
Nitrogen is abundant in the atmosphere, but plants cannot use it because of the absence of a necessary enzyme, nitrogenase, which converts nitrogen into a usable form. So they form a symbiotic relationship (mutually-beneficial arrangement) with nitrogen fixing soil bacteria (rhizobia) which perform biological nitrogen fixation. Biological nitrogen fixation is a process in which the symbiotic nitrogen-fixing bacteria coverts atmospheric nitrogen into ammonia and organic derivatives that plants can use to synthesize proteins. This bacteria form nodules on the roots of plants like legumes in which nitrogen fixation takes place.
Both plants and bacteria benefit from this symbiotic relationship, as the plant obtains ammonia to synthesize proteins from nitrogen in the atmosphere while bacteria obtain carbon compounds from the plant produced through photosynthesis and a secure environment to grow. As the plant roots leave behind some of the usable form of nitrogen in the soil, this process also increase soil fertility.
