Question

true or false

1. The origin of photosynthesis led to an increase in methane in the atmosphere.

2. Stromatolites are evidence of the origin of prokaryotes.

3. Lamarck’s theory of inheritance of acquired characteristics is a commonly accepted mechanism of evolution.

4. The Permian Mass Extinction was likely caused by an enormous meteorite strike to the earth.

5. The Cambrian Explosion is the time period when the diversity of mammals expanded on earth.

Answer 1

1. False - when cyanobacterias appeared they started using water to obtain hydrogen and release oxygen. This addition of oxygen to the atmosphere started oxidising methane and ammonia, which later began to dissappear

2. True - Stromatolites are the rock like structures which are found in shallow water . Mucous secretions of cyanobacteria(prokaryote) collects sediment grains and stick it with calcium carbonate from the bacteria itself and hence forms stromatolites.Hence it serves as evidence.

3. False- Lamarcks theory is no longer considered. All our traits are resut of natural selection and genes . None of our traits are changed according to our increased usage

4. True- Although there are studies which suggest it may have been caused by volcanic erruptions or sudden climatic changes, most sought answer is a large meteor impact.

5. False- Studies suggest this was the period when bryozoans, brachiopods, corals, nautilods and crinoids developed and not mammals.