Explain why, for each pregnancy, human

parents have a 50 percent probability of having

a boy and a 50 percent probability of having a

girl.

Explain why the growing of willow for biofuel is an example of sustainable development.

Which describes how precipitation falls in mountainous regions? a) in small quantities on both sides of mountains b) in large quantities on both sides of mountains c) more on the windward side of mountains d) more on the leeward side of mountains

Nucleic acids offer variability because they contain alternate for of genes called what

21. What would it mean if a food burns more intently than another?

A group of science students have been learning how the human circulatory system reacts during exercise. The students measured their heart rates both before and after they ran five laps around the school gym.

Marks: 1 the circulatory movement that occurs in a gas or fluid with areas of differing temperatures due to the variation of the density and the action of gravity is called:

there is 30 percent more what in earth's atmosphere today than there was before the start of the industrial revolution

Scientists say that conditions must be "just right" for a hurricane to start up. Which is the first step of "just right" in the development of a hurricane? A) Cool ocean water replaces warmer surface water.

What is another name for a tropical savanna?

What is a substance in plant sources that cannot be digested that is 5 letters