Answer: It's an EXPERIMENT
Explanation: Experiment is done when we apply anything to a samples or conditions in other to study another sample or conditions.
Observation is done when, we study samples or conditions in it's natural way, without application of anything that may alter it's result.
Because the researcher has applied fertilizer to one side and did not apply to the other side, that means he has performed an experiment. Since he wasn't observing the two sample in it's natural way without any external application.
Answer:
filamentous algae
According to 2 sources
Spirogyra is a filamentous algae, commonly found in freshwater ditches and ponds. Go through this article for a brief overview about these algae. Spirogyra is also known as pond silk, as its filaments shine like silk due to the presence of mucilage. The outer cell wall has pectin which dissolves continuously, thereby producing the mucilage
The correct answer would be option A, the negative symptoms of schizophrenia
His demeanor is unusual compared to most people because he does not show emotional expression when he speaks, and does not appear to have the ability to read other's emotional expressions. These symptoms are also known as the the negative symptoms of schizophrenia.
Explanation:
Schizophrenia is a mental disorder in which people cannot interpret the reality normally. Their thoughts, feelings, perceptions, behaviors and emotions are all faulty and abnormal. Schizophrenia can cause delusions, hallucinations and extremely disordered thinking.
There are two types of symptoms of schizophrenia. One is Negative and the other is positive. Positive symptoms may include hallucinations, delusions, and racing thoughts, whereas negative symptoms may include apathy, lack of emotion, poor or nonexistent social functioning, etc.
So when Barry does not show his emotional expressions when he speaks, it means he has negative symptoms of Schizophrenia.
Learn more about Schizophrenia at:
brainly.com/question/6868018
#LearnWithBrainly
