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.
ans is D. Most items are features in the spinal cord, but the hippocampus is in the brain.
Answer:
I assume you are referring to bees?
Explanation:
From what I know and this is just surface level knowledge, she is the one who births the hive and usually designates their purpose once she has laid the eggs. She herself does not do much, she is just the one that the infrastructure of the hive follows in maintaining the hive itself. I hope this helps. Good luck!
The correct option is this: PLANTS CAN BE USED TO MAKE MATERIALS.
Plants are very important living organisms and they can be used in diverse ways. Some plants can be used as foods, some plants are used as raw materials for making pharmaceutical drugs and other herbal products. Plants, such as cotton are used to make clothing materials and dead and decaying plants serves as fertilizer that add nutrients to the soil.
Cell- <span>the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.</span>