Answer:
Vertebrates are further classified according to several criteria like exoskeleton, respiratory organs, method of giving birth, number of chambers in heart, mode of living etc. They are further classified into classes Pisces, Amphibia, Reptilia, Aves and Mammals
<span>Answer: a. Citizens over the age of 65 use social media primarily to follow the activities of their families. </span>
<span>More than half of the citizens over 65 say that they have a social media account. They read other postings but post information about one-fifth as often as they read posts. Most of their feeds consist of posts by relatives. From this passage, we can logically say that Citizens over the age of 65 know how to use the social media and they use it primarily to follow the activities of their families. </span>
Answer:
Rocks.
Explanation:
Scientists study rocks from the Precambrian period because isn't really a significant fossil record from the Precambrian.
<span>The ability to choose a mate does improve offspring fitness in fruit flies. The choice made by the female fruit fly is based on a recognition pattern of the male's ability to highlight its potency and "genes".
As a conclusion, the better the male's genes, the better the offspring's fitness.</span>
