Answer:
A cell cycle is a series of events that takes place in a cell as it grows and divides
Explanation:
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Answer:
Watson and Crick proposed the double helical model of DNA.
Explanation:
- This model says that DNA exist as double helix. It has two polynucelotide strands running in opposite direction i.e the strands are anti-parallel.
- Each polynucleotide strand is made up of several nucleotide liknked together by phophodiester bonds.
- The two strands are not coiled upon each other but the double strand is coiled upon itself around a common axis like the spiral stair case. Here base pairs forms the stairs and backbone of two strands form railing. Back bone contains sugar and phosphate.
- The base pairing is specific, adenine always pairs with thymine and guanine always pairs with cytosine. Thus if we see any base pair, it consists of one purine and one pyrimidine.
- The two strands of DNA thus show complementary base pairing.
- The strands are held together because of hydrogen bonding between the bases in opposite strand.
- One full helical turn involves ten base pairs and the base pairs are stacked 3.4 A apart.
- This form is called as B-form of DNA.
Answer:
Sand
Explanation:
Space, water, energy, and air are all needed for an organism to survive. Sand is just somewhere an organism could accustom to live in that environment.
Assessing aggregate exposure to a series of compounds with the same biological mechanism is called cumulative exposure assessment.
<h3>
What is cumulative exposure?</h3>
Because cumulative exposure evaluations evaluate exposure to numerous stressors via different pathways, they are referred to as "combined exposure assessments." Exposures to a single stressor are estimated using aggregate evaluations from different sources and pathways.
Cumulative evaluations portray real-world exposure more accurately, but they also provide an element of complexity not seen in typical exposure assessments , which evaluate stressors separately.
Learn more about cumulative exposure refer:
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Carrier proteins are the proteins in active transport
