Answer: The correct answer is A) A+C=G+T
According to Watson and Crick base pairing-
In a double stranded DNA molecule, Adenine pairs with Thymine and Guanine pairs with Cytosine. This means that number of Adenine in one strand is equal to the number of thymine in the complementary DNA strand. Similarly, the number of Cytosine in one strand is equal to the number of Guanine in the complementary strand.
Thus, the total number of Adenine and Cytosine in one strand becomes equal to the total number of Guanine and Thymine in the complementary strand.
This can be mathematically written as- A+C = G+T
Thus, option A) is the right answer.
The correct answer is: b. it doesn’t often reflect reality.
While experimental research has several advantages, including: investigating the effect of one variable on another, and the ability to control and eliminate confounding variables, it also has one major disadvantage. This disadvantage is known as: <em>lack of ecological validity</em>.
Lack of ecological validity means that the findings of research study might not be generalizable to real-life settings, and might only apply to laboratory settings. To avoid the problem of ecological validity, and to increase the validity of an experimental research study, a study should be conducted in natural settings when possible.
The answer for this question would be Integument, digestive, respiratory and urogenital.
The largest system that contact with the external environment would be integument and digestive. That makes two system has normal flora of microbes and not sterile like the other systems. Normal flora of microbes will prevent the pathogen microbe grows so it gives some benefit.
I think it’s F, c, and a.
100,000 years ago is your answer
