Question: Answer the following question given this paragraph: The gonads secrete sex hormones. The male gonads are called testes . They secrete the male sex hormone testosterone. The female gonads are called ovaries . They secrete the female sex hormone estrogen. Sex hormones are involved in the changes of puberty. They also control the production of gametes by the gonads. Q: The testes produce what hormone? Choices: - dopamine - insulin - estrogen - testosterone A:
Answer: testosterone

Question: Answer the following question given this paragraph: Blood flows through the heart in two separate loops, which are indicated by the arrows in Figure above. You can think of them as a "left side loop" and a "right side loop. " The right side of the heart collects oxygen-poor blood from the body and pumps the blood to the lungs. In the lungs, carbon dioxide is released and oxygen obtained by the blood. The left side of the heart carries the oxygen-rich blood back from the lungs and pumps it to the rest of the body. The blood delivers oxygen to the body's cells, returning the oxygen-poor blood back to the heart. Q: What type of blood does the right side of the heart collect and then pump to the lungs? Choices: - nitrogen-rich blood - oxygen-rich blood - nitrogen-poor blood - oxygen-poor blood A:
Answer: oxygen-poor blood

Question: Answer the following question given this paragraph: Q: What type of air do plants take in and use? Choices: - oxygen - liquid dioxide - carbon - carbon dioxide A:
Answer:
carbon dioxide