<h2>Answer:</h2>
The correct statement is option A which is, "A gene is a segment on the DNA. DNA is wrapped in proteins to form a chromosome".
<h3>Explanation:</h3>
- A gene is the part of DNA in the nucleus which encodes for the specific trait in the body. DNA is the nucleotide sequence which is the blue print for the whole organism. It contains genes for all the structures and functions in the body.
- So it is very long sequence containing the million of genes. So in nucleus it is present in compress form. It is wrapped on the histones proteins and condense and supersondense into a specific structure which is known as chromosome.
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.
Answer: Respiratory system, Excretory system, and Endocrine system.
Explanation:
Homeostasis is the process through which several organ systems work to maintain a stable internal environment in the body. There are three organs of the body which ar eaccurately maintained by homeostasis:
Respiratory system: High carbon dioxide content in the blood triggers faster breathing. Most frequently, the lungs exhale, which quicker extracts carbon dioxide from the body.
Endocrine system: High blood sugar content causes insulin release by an endocrine gland called pancreas. Insulin is a hormone which helps the cells absorb blood sugar.
Excretory system: A low blood level of water causes kidney accumulation of water. The kidneys contain more concentrated urine, so less water from the body is lost.
Hence, three critical areas are respiratory system, excretory system, and endocrine system that are accurately maintained by homeostasis.
