Answer:
The correct answer will be option E.
Explanation:
The features given in the question are the characteristics features of the group of bacteria belonging to Cyanobacteria.
These Cyanobacteria are the prokaryotes which are capable of synthesizing the food through a process called photosynthesis. These bacteria use sunlight as their energy, use water and air to synthesize food. They under anaerobic condition synthesize the nitrogen in special structures called heterocyst, a characteristic feature of cyanobacteria.
Thus, the features given in the question are:
1. contain photosystems to carry out photosynthesis.
2. producing oxygen
4. contain phycobilins
6. Hetrocysts: nitrogen-fixing structures.
7. The ancestor of plant chloroplasts.
Thus, option E is the correct answer.
D- species
A biological species is a group of organisms that can reproduce with one another in nature and produce fertile offspring.
The correct answers are "sometimes, no change or reduced".
If our sensory systems are exposed to the same exact stimulus repeatedly, sometimes it causes our sensory systems to react and sometimes it has no effect. In some cases, it may have a reduction of sensitivity, but sometimes it has no effect to our sensory systems.