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.
Answer:
Giraffes usually only have a single baby, born after a 15-month gestation period. But because they're able to breed all year round, giraffes don't need to 'resynchronise' with the seasons each time they give birth. Sadly, about 50% of giraffe calves do not survive their first year.
Explanation:
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<h2>Question:</h2>
Where is DNA present inside a eukaryotic cell?
<h2>Answer:</h2>
<h2><em><u>Nucleus</u></em></h2>
It is most likely due to the fact that the attenuation is the evolutionary relic, which by accident has remained does not support the actual reason of the dual control to regulate the operon.
Answer: Option E
<u>Explanation:</u>
In bacteria transcription and translation carries out at the same time so or the termination of transcription in premature phase in bacteria uses a special mechanism which is called as attenuation T.
he attenuation in bacteria is a regulatory mechanism. Trp operon is the group of codes of the components. These operons are the actual functioning group of the DNA.
Your DNA is comprised of chromosomes which is comprised of genes. Your genes determine which inherited traits you receive from your parents. When you parents "make you" they each donate 16 chromosomes that contain many genes. These chromosomes make up your DNA, which effects your inherited traits such as, eye color, and hair color.
Hope this helps!
