Answer :Erwin Chargaff a Biochemist
Explanation:
He formulated the base paring of double helix of DNA. He reasoned that since the percentage of four DNA bases are of this proportions in human;
Adenine=30.9% and Thymine =29.4%;
Guanine=19.9% and Cytosine =19.8%
Then, the amount of adenine will always be equal to thymine,
And the amount of Guanine equals to cytosine based on this percentages of distribution.
(Adenine and Guanine are large, molecule of Purines, while thymine and Cytosine are Pyrimidine)
He concluded (although scientist believed, he did not explicitly stated this) that this should be the base paring patterns in DNA molecule. This is the first Chargaff Rule.
His second rule is that the DNA composition, in the relative amount of the four bases Adenine, Thymine, Cytosine and Guanine varies in proportion from one organisms to another. And this is the basis of molecular diversity.
A derived trait is a trait that the current organism has, but the previous one did not have.An ancestral trait is a trait that you, and your ancestors had.A vestigial structure is a structure that had some sort of use in your ancestor, but none in your current body
Transpiration is the process where plants absorb water through the roots and then give off water vapor through pores in their leaves, so D would be your answer
Answer:
Abiotic components of an ecosystem are water, air, light, soil, and temperature.
Now think about how the availability of these things will affect what could live in a specific area.
Consider a desert ecosystem. Deserts are arid, receiving little rain (water) and have extreme temperatures (both cold and hot). Because of these conditions only certain plants and animals can live here. These plants and animals have adaptations that are specific to the environment. If you were to put an organism that does not belong in there, they would most likely die out.
Tidbit for you. The Atacama desert is one of the driest places in the world, located specifically in Chile. At one point, this place did not receive any rain for 500 years! Still plants and animals are able to live in this area. When it finally did rain, the sudden downpour caused a radical change in this ecosystem. You would think at first rain would be good, but no. Because the changes the rain brought was too drastic, it caused a devastating effect on the organisms that lived there because they were not adapted to rain.
The outer periphery of the inter-vertebral disk is composed of strong fibrous tissue called the Annulus fibrosus. This is a tough circular exterior of the inter-vertebral disc that surrounds the soft inner core, the nucleus pulposus. The outer portion is composed of a ring of ligament fibers that encases the inner core of the disc and securely connects the spinal vertebrae above and below the disc.
