Biết đậu Hà Lan là loài tự thụ phấn nghiêm ngặt alen A quy đinh hạt màu vàng alen a quy định hạt màu xanh. Cho cây mọc từ hạt vàng thuần chủng thụ phấn với cây mọc từ hạt xanh thu được F1. Cho F1 thụ phấn được F2. Biết không xảy ra đột biến a, Xác định tỉ lệ màu hạt của các cây thế hệ F1 và F2. B, Nêu nhận xét và giải thích mối quan hệ giữa thế hệ cây và thế hệ hạt ở thí nghiệm trên

The phlogiston theory in the 17th century attempted to explain burning. the theory stated that combustable objects contained a material called phlogiston, a substance without mass, color, odor, etc. after objects burned, the objects were dephlogistonated and were then in their true form. the phlogiston theory was accepted until the 18th century, when lavoisier proved that combustion requires a gas that has mass. phlogiston is considered a) to be scientific knowledge b) not to be scientific knowledge c) to be proven by scientific method d) to be accepted in the modern scientific community

To take a whiff of your favorite food, you use both? a. motor nerves and your digestive system b. sensory nerves and your immune system c. motor nerves and your skeletal system d. sensory nerves and your respiratory system

Abeaker of water was heated and then placed on a bench in the laboratory. the water cooled until it was the same temperature as the air in the laboratory. which of these explains the mechanism by which the water cooled? a. heat energy was transferred from the water to the air. b. water molecules from the water formed warm water currents. c. the water molecules absorbed energy from the molecules in the air. d. the water released radiation until it contained no heat energy.