Answer:
I believe it is Hubble's law but I could be wrong
Answer:
Graptolites lived from the Cambrian Period, about 510 million years ago, disappearing in the Carboniferous Period, around 320 million years ago.
hope this helps!
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Im not sure cuz why theres O in there? I thought there’s only 4 bases Adenine Thymine Guanine Cytosine and in RNA there’s Uracil instead of Thymine. Sorry
