Answer:
A country is considered tropical when it lies between the Tropic of Cancer and the Tropic of Capricorn.
Explanation:
The equator is located between the tropics
Answer:
Natural selection leads to evolution.
Answer:
The placenta is a unique vascular organ that receives blood supplies from both the maternal and the fetal systems and thus has two separate circulatory systems for blood: (1) the maternal-placental (uteroplacental) blood circulation, and (2) the fetal-placental (fetoplacental) blood circulation. The uteroplacental circulation starts with the maternal blood flow into the intervillous space through decidual spiral arteries. Exchange of oxygen and nutrients take place as the maternal blood flows around terminal villi in the intervillous space. The in-flowing maternal arterial blood pushes deoxygenated blood into the endometrial and then uterine veins back to the maternal circulation. The fetal-placental circulation allows the umbilical arteries
Explanation:
Answer:
Por medio de las hojas, las plantas realizan la fotosíntesis, respiran y producen los alimentos. La respiración se produce durante el día y la noche; para ello, las plantas toman el oxígeno del aire y desprenden dióxido de carbono.
Explanation:
Por medio de las hojas, las plantas realizan la fotosíntesis, respiran y producen los alimentos. La respiración se produce durante el día y la noche; para ello, las plantas toman el oxígeno del aire y desprenden dióxido de carbono.
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. ... By feeding on plants and on one-another, animals play an important role in the movement of matter and energy through the system.