Biology Questions

Chloroplasts contains chlorophyll, the green substance in plants that allows them to create food from carbon dioxide and water called as photosynthesis.

DNA is not a single stranded and does not have amino acids. Hence options, b & C are eiminated. Dna is a double helix structure containing nucleobase—either cytosine (C), guanine (G), adenine (A), or thymine (T)—as well as a monosaccharide sugar called deoxyribose and a phosphate group. 

The statements true about viruses are :

1. The capsid enters the host cell if the virus is enveloped.

2. Enveloped viruses bud from the host cell. 

3. HIV contains reverse transcriptase.

4. A retrovirus contains RNA.

HIV is a virus that damages the immune system. HIV is a lifelong condition, and without treatment, a person with HIV can develop AIDS.

Arteries carry oxygenated blood away from the heart to the tissues, except for pulmonary arteries, which carry blood to the lungs for oxygenation (usually veins carry deoxygenated blood to the heart but the pulmonary veins carry oxygenated blood as well).

At the synapse between two neurons, electrical signals are converted into chemical signals. A synapse is the gap between the two neurons.

Receptors for hearing the organ of corti or the spiral organ is located in the the mammalian cochlea.

The purines are bases in the DNA. The two purines in DNA are Adenine and Guanine. These two purines forms hydrogen bonds with their complimentary pyrimidines such as Thymine and Cytosine to keep the two rails of the DNA molecule together.