They get a sense of the history of the area they are investigating.
Density of a rock and age of a rock require very specific tests that are irrelevant to the relationships between the rock tested and other layers.
Value of a rock is very subjective to the use that can be made of the rock and also tells nothing about the relationships between layers.
Brainliest?
Answer:
D. 365 days
Explanation:
Revolution means covering distance and moving around the sun so it takes a year or 365 days revoluting around the sun.
B cells produce antigen
t cell are helper,killer,memory cells
they hold memory of pathogens i the system
Answer:
Option C
Explanation:
Complete Question
Which of the following situations would pose a major difficulty for applying the biological species concept?
a) Two populations of sexually reproducing plants that can be bred easily in the same location under field conditions
b) Two populations of sexually reproducing insects that can be bred easily in the same location under field conditions
c) Five snail fossils taken from the same locality during a 400,000-year time span
d) Dimorphic mating pairs of birds
e) Monomorphic mating pairs of birds
Solution -
According to the biological species concept, two or more organisms that look alike does not mean that they belong to the same species. In order to consider that two organisms belong to the same species, it is essential for them to be able to interbreed or mate.
For example –
Western meadowlarks and Eastern meadowlarks look identical to one another but they do not interbreed with each other and hence they belong to different species.
Hence, option C is correct
Stars as large as Betelgeuse are very unusual. In contrast, Rigel, the bright, bluish-white star at the southwest corner of Orion, is smaller and much hotter than Betelgeuse. Although Rigel is smaller than Betelgeuse, it is still a super-giant star compared to the sun.
hope this helps ^^
