Answer:
The correct option is <u><em>A. they evolved from land mammals.</em></u>
Explanation:
The process of evolution explains how closely one organism is to another based on their common ancestors. Scientists believe that those organisms which show many similarities in their structures or functions might have evolved from a common ancestor in the past.
As in the above-mentioned question, scientists have observed that cetaceans lack gills and breath air, this is a property of land mammals. The cetaceans have fin bones which are similar to the limb bones. As limb bones are present in land mammals, hence they cetaceans and land mammals might have common ancestors in the past.
Answer:
a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
Explanation:
Kinetochores have vvery important role in the cell division-mitosis.
During the metaphase of mitosis, spindle fibers attach to kinetochores. Some of the microtubules bind to kinetochore (kinetochore microtubules) while other don’t: they connect with the microtubules from the opposite pole, stabilizing the spindle.
During the anaphase, kinetochore microtubules pull chromosomes toward poles, helping the sister chromatids separate from each other.
False, only some . Hope this helps !
Convert 24 hours into minutes
24 hours = 1440 minutes
Divide 1440 by 15
There’s 96 divisions
Now take 2^96 power
You will have 7.9 x 10^28 bacteria