Consider statements about environment: 1. Carbon dioxide is a greenhouse gas. 2. Methane is a greenhouse gas. 3. Oxygen is a major greenhouse gas. Which are correct? MCQ with Answer and Explanation
Consider statements about environment: 1. Carbon dioxide is a greenhouse gas. 2. Methane is a greenhouse gas. 3. Oxygen is a major greenhouse gas. Which are correct?
A. 2 and 3 only
B. 1, 2 and 3
C. 1 and 2 only
D. 1 and 3 only
Answer: Option C
Solution (By JKExamLibrary)
Greenhouse gases trap heat in the Earth's atmosphere, contributing to the greenhouse effect and global warming. Carbon dioxide (CO2) and methane (CH4) are potent greenhouse gases emitted through human activities like fossil fuel combustion and agriculture. Oxygen (O2) and nitrogen (N2), which make up the majority of the atmosphere, are not greenhouse gases as they do not absorb infrared radiation. Thus, statements 1 and 2 are correct.
Explanation:
Amphioxus (Branchiostoma) is a cephalochordate that retains the notochord, dorsal nerve cord, and pharyngeal slits throughout its life. In vertebrates, the notochord is largely replaced by the vertebral column during development. Amphioxus is a key model for studying vertebrate origins.
Explanation:
Natural passive immunity occurs when pre-formed antibodies are transferred naturally from one individual to another. During pregnancy, maternal antibodies (primarily IgG) cross the placenta to the fetus, providing temporary protection against diseases the mother is immune to. Colostrum (mother's milk) also provides IgA antibodies to the newborn.
Explanation:
Aqueous humor is a clear fluid in the anterior and posterior chambers of the eye, providing nutrients and maintaining intraocular pressure. Vitreous humor is the gel in the posterior segment.
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