What are the pairs i need them before i can try to answer
I think the answer to this is the kidneys
Explanation:
The dog salivating is an example of responding to stimuli
Answer:
Reproductive isolation refers to the inability of an organism or species to breed successfully with other organism or species.
It may arise from various factors such as:
- Geographical isolation such as river, mountain, etc
- Behavioral changes such as mating time or season, mating rituals, mating location etc.
- Physiological differences such as change in shape of sex organs which causes lack of fit between copulatory organs.
- Genetic differences.
Reproductive and geographical isolations between two populations (of same species) inhibit the flow of genes among them. Slowly, these isolations increase the variations in the gene pools of the two populations.
These genetic variations keep on increasing with time. In addition, as an adaptation to their surrounding or habitat the two populations would develop different behavioral and physiological changes
With time, these differences will increase up to such an extent that the two populations would not be able breed with each other. Hence, it would lead to the evolution of one or both the populations into new species.
Answer:
If your just looking for a description here you go.
Explanation:
Most spiral galaxies contain a central bulge surrounded by a flat, rotating disk of stars. The bulge in the center is made up of older, dimmer stars, and is thought to contain a supermassive black hole. Approximately two-thirds of spiral galaxies also contain a bar structure through their center, as does the Milky Way.
Hope this helps.
