Which of the following is an example of a mutualistic symbiosis?
A. Mosquito sucking blood
B. Tapeworm in human gut
C. Lichen (algae and fungus)
D. Barnacles on whale skin
Answer: Option C
Solution (By JKExamLibrary)
Lichens are a mutualistic association between an alga (or cyanobacterium) and a fungus. The alga photosynthesizes, providing food; the fungus provides shelter, water, and minerals. Both benefit. Tapeworm is parasitism, barnacles on whales commensalism (or sometimes parasitism depending on effect), mosquito blood-sucking is parasitism.
Explanation:
Crossing over occurs during prophase I of meiosis, not in mitosis. Mitosis produces identical diploid cells, meiosis reduces chromosome number by half, and cytokinesis divides the cytoplasm.
Explanation:
Bacteria are prokaryotes with a single circular chromosome in a nucleoid region, without a nuclear membrane. They lack membrane-bound organelles like mitochondria. Their chromosomes are not linear; eukaryotes have linear chromosomes.
Explanation:
The iris is the colored part of the eye containing smooth muscles (sphincter and dilator pupillae) that adjust the pupil diameter to control light entry. The cornea and lens focus, retina senses light.
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