How does carbon dioxide enter the atmosphere?

1. Animal respiration

2. Pollution - combustion

3. Dead animals decomposition

4. Dead plants

5. All of the above

What's is happening to the total amount of water on earth

Which four molecules are the DNA

In prokaryotic and eukaryotic cells the amount of water in the cell is kept at a steady state. The organelles through which water passes into and out of cell is the A) cell membrane B) cell wall C) nucleus D) ribosome

Which type of joints is found between the lower jaw and skull

How do breeders produce genetic variations that are not found in nature

Humans and apes have five fingers they can use to grasp objects. do you think these are analogous or homologous structures? explain your answer.

During which two minute time period is the temperature of the water changing fastest?

The human body is made up of: nucleus absorption cells neurons

Why is photosynthesis important for plant cells

What challenges do you think scientists face when classifying new organisms?