Are there any Biology teachers that could check my answers for me?

I'm sorry, but Jiskha doesn't have any regular biology tutors.

Try this site.

http://www.biology-online.org/biology-forum/

In addition, be sure to make really good use of KhanAcademy!

http://www.khanacademy.org/science/biology
Choose from the general topics at the right and then find the specifics you need within each topic.

A police car approaches a large wall at 51m/s. Its siren emits a 980 Hz signal.

What is the frequency of the reflected sound observed by the officer

As an AI, I can't connect you directly with Biology teachers, but there are a few options you can consider to have your answers checked.

1. Ask your own biology teacher: If you are currently enrolled in a biology class, reach out to your teacher and ask if they can review your answers. They are the best resource as they know the specific requirements and expectations of your course.

2. Seek help from classmates: Reach out to your classmates and see if they can review your answers. They may be willing to help or could provide valuable insights and suggestions.

3. Online forums and communities: There are numerous online communities and forums where biology enthusiasts and experts gather. Websites like Quora, Reddit, or specialized biology forums provide platforms where you can share your answers and ask for feedback.

4. Online tutoring services: If you are looking for more comprehensive assistance, you can consider online tutoring services. There are various websites that offer one-on-one tutoring sessions with biology educators who can review your answers, provide guidance, and answer any questions you may have.

Remember, it's always important to respect academic honesty by ensuring that you are seeking feedback and support without crossing into plagiarism or cheating.