Answer:
I would say the first option
Explanation:
The excretory system allows animals to remove metabolic waste their bodies. Many of these substances are potentially toxic. in Mammals nitrogenous toxins like urea are expelled through liquid urine while in reptiles and birds the nitrogenous compounds are expelled as a solid. This allows birds and reptiles to use less water in the processes of metabolism.
Answer:
primary succession takes longer
Explanation:
Primary succession is built from the ground up, whereas secondary succession is built from an already existing civilization.
Answer:
The vascular system
Explanation:
The human blood circularitory system can be used to explain capillary action in the human body, our heart pumps blood in and out with no use of external forces.
Answer:
Artifical Selection OR Cross Pollination
Explanation:
If white roses and red roses are cross-bred by scientists, it would be artifical selection. If they were crossed in nature, it is called crossed pollination.
