10. Today, the fossil record A. can be dated reasonably well only with uranium-2
ID: 199243 • Letter: 1
Question
10. Today, the fossil record A. can be dated reasonably well only with uranium-238. B. can be dated precisely, to within a single year, using DNA hybridization. C. can be dated only with one layer in relation to older layers below and younger layers above, no actual dates can be estimated D. can be dated precisely, to within a single year, using radioactive isotopes. E. can be dated reasonably well using a variety of radioactive isotopes with known half-lives. 11. Progressive changes in the fossil record are evidence for evolution because A. they show evolutionary change at the level of the individual. B. they show descent with modification. C. they show gaps in the fossil record. D. they show inheritance of acquired characteristicsExplanation / Answer
23) Temporal isolation is considered as a reproductive barrier. It is defined as 'Isolation in time', which means different species breed at different times. This difference can be in different timings of the same day or during different seasons in a year or even in different years. And this temporal isolation is one of the possible causes for Speciation.
So, among the given examples, the isolation in time is option C, where one species blooms in june- july and a second plant species blooms in August - september. Here, the breeding seasons are seperated by different months in a year (ie; at different timings).
24) Cichlid fishes in lake Victoria is an example for extremely rapid diversification. The reason that accounts for their tremendous success in differrent habitats is option E, ie the presence of second set of jaws in their throats. In 'throat jaws' they have teeths present in addition to the regular jaws. This provides them a selective advantage because, they are capable of eating anything that is available to them without being dependent on a particular food source. So, in their habitat when there occurs severe competition for food, they can survive as they feed on anything without restricting their food source. These throat jaws which are posessed with modified gill bones serve as an addditional food processor which helps them to crush even the hardest prey that comes their way.This made them adaptable to extremely diverse habitats.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.