Answer:
the external appearance of a plant community, which changes throughout the year in accordance with the succession of the phases of development of plants. As a rule, aspect is repeated year in and year out in almost identical sequence.
Abiotic are the nonliving things in an ecosystem such as climate and soil type.
<u>Answer:</u>
The Acquired Immune Deficiency Syndrome (AIDS) was clinically identified as a fatal disease in 198.1 decade.
<u>Explanation: </u>
AIDS which is a pandemic globally, is caused by a communicable virus called Human Immunodeficiency (HIV) Virus. In US, the first five cases were clinically exposed on 5th June, 1981. HIV majorly spreads from one to the other through three routes namely sexual contact, transmission through body fluids or from mother to fetus via pregnancy/ delivery/ breast-feeding. Vaccines that offer partial protection exists but there is no permanent cure for this disease.
1. True- because scientific theory means that <span>idea supported through research that attempts to explain existing observations or predict new ones.</span>2. False- because a cross-sectional means that its a study that is about different groups.
3. B-<span>An extraneous variable clarifies the relationship between the independent and dependent variables.</span>
Pain signals move from peripheral nervous system to the spinal cord and many gates are present in between which regulate these signals. The slow pain signals then move from the spinal cord to the <span>hypothalamus and limbic system. The former releases hormones which are stress-related, the latter is associated with the emotions and feelings related to the same. These signals are slow because they pass through the brain parts which are responsible for the emotions also, which is limbic system and prefrontal cortex. This lag time enables the person to feel the severity of pain and protect from it. For example, the soldier feels less pain because he is attached to the war scenario in a different manner, as compared to the civilian, and therefore, pain signals follow a different pathway, leading to a feeling of comparatively lesser pain and other activities are less affected.</span>
