Here are the correct answers to each of your questions:
1. **Which of the following is a true statement about the differences between prokaryotic and eukaryotic cells?**
**Answer:** Eukaryotic cells have a nucleus, but prokaryotic cells do not.
2. **Which of the following cell structures are present in PLANT cells but NOT animal cells?**
**Answer:** Chloroplasts.
3. **Which part of the brain are most helpful specifically for the activities performed by a gymnast?**
**Answer:** Frontal lobe and cerebellum.
4. **All plants exhibit alternation of generation?**
**Answer:** True.
5. **When can a heartbeat of a developing human be heard through a stethoscope?**
**Answer:** Second trimester 13-24 weeks.
Let me know if you need any further assistance!