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.
Explanation:
Spillover infection, also known as pathogen spillover and spillover event, occurs when a reservoir population with a high pathogen prevalence comes into contact with a novel host population. The pathogen is transmitted from the reservoir population and may or may not be transmitted within the host population.
Answer:
W- developed seeds
X-angiosperm
Explanation:
Well for one, these two are the only things w/ a referrable image (I'm not sure if that's a word :-)) Another thing is angiosperm literally means flowering plant and a tomato is a ripe, or flowering, plant. W is an image of seeds that are at mid stage in there developing process, so it is clearly the answer. Correct me if im wrong :-D.
Answer:
Exploration and Discovery, Testing Ideas, Community Analysis and Feedback, and Benefits and Outcomes are the four phases that make up the Scientific Process. The Scientific Process, on the other hand, is a method for evaluating ideas that follows a straight path.
