Answer:
a. Mammalia
Explanation:
Mammalia are the class species that have distinct systems and separate ducts for different activities like reproduction, excretory, and defecatory and moreover they have nipples to feed their young ones.
So, the above species which has a single duct for reproductive, excretory, and defecatory material as well as a lack of true nipples does not belong to Mammalia
The maximum density is 4 degrees Celsius :)
serving size is a set portion created by the government. it is the optimal amount of food/liquids to be consumed by one person.
The nitrogenous bases placed in between the DNA double helix strands, like rungs on a ladder, are positioned there because of the hydrophobic effect and are stabilized by hydrogen bonding. The stability of DNA also relies on the interactions between the hydrogen bonds between bases, hydrogen bonds between bases and surrounding water, and base interaction between neighboring bases.
Hydrogen bonds are able to stabilize the DNA double helix by pairing up with their complementary base pairs (guanine with cytosine and adenine with thymine)
Hope this was able to help you! I went through my answer and bolded the more important parts, and parts more useful for answering the question.