Answer:
All the options are true except option D.
Explanation:
Archaea are a group of prokaryotic organisms i.e. they lack a membrane bound nucleus. They are one of the the three domains of life (the other two being bacteria and eukarya). Archeans possess a cell wall like bacteria but it is not composed of peptidoglycan, like bacteria cell wall.
Archeans are generally known to be found in very severe environmental conditions, hence, they are referred to as extremophiles e.g Some are thermoacidophiles i.e. thrive in very hot and acidic environment while others are extreme halophiles i.e. thrive in salty regions. Archeans known as methanogens produce methane gas as a product of metabolism from carbon dioxide and hydrogen.
However, the domain archeae was only found to be in existence recently after the domain bacteria, hence, they are not considered to evolve before the domain bacteria.
Answer:
Invertebrates are the organisms in which backbone or vertebral column is absent.
The three macroinvertebrate categories are annelids, mollusks and arthropods.
Annelids are the organisms having segmented body. They are found in moist places. Examples are leeches and earth worms.
Mollusks are the organisms which are enclosed in a calcium carbonate shell. Examples are snails and slugs.
arthropods are the invertebrates which have segmented body and jointed appendages. Examples are insects and crustaceans etc.
No generations or hybrid would form before meselson and stahl would have observed evidence of a band in the cscl gradient.
The conservative model predicts that, following a single replication, half of the newly formed DNA double helices will be made entirely of the original, or old, DNA, and the other half will be entirely new. Then, each double helix would be completely replicated during the second round of replication. After that, 25% of the double helices would be all new, and 25% would be entirely old. Thus, the fraction of entirely new DNA double helices would increase with each succeeding round of replication, but the total number of completely unique DNA double helices would remain constant. Therefore, no hybrid DNA molecule containing 14N and 15N is replicated in the conservative model.
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Answer:
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