How much of the world's diversity is threatened as tropical forests are converted to agricultural use?
20 percent
30 percent
40 percent
50 percent

Ais a landform that is formed at the mouth of a river from the deposition of sediment carried by the river as the water flows.

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

Crossing over and independent assortment are important activities that occur during meiosis. what is the significance of these activities