Many different microscopic organisms can be found in pond ecosystems, including the three organisms shown in the diagrams below. The primary cellular structures in each of these single celled organisms are labeled in the diagram. Some of the structures are common to all three organisms and other tures are not. One of the three organisms below can obtain energy through photosynthesis. a. Based on the diagrams, identify which organism is able to perform photosynthesis. Explain your reasoning.

b. Identify the two reactants for photosynthesis.

c. At times, this photosynthetic organism can switch to being heterotrophic. Describe a condition that would favor this organism being heterotrophic. Explain your answer.
Answer using 2 to 3 complete sentences for each question.

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?

Which type of neuron stimulates muscles to contract?