Answer:
The earth developed seasons during the Late Precambrian eon.
Explanation:
The chloroplasts had inner membrane
Explanation:
The primitive photoautotrophs utilized hydrogen sulphide as the electron donor to perform photosynthesis for energy production.
Later upon understanding the endosymbiotic relationship of cyanobacteria which resided in the mitochondria of a eukaryotic host cell, the use of chloroplasts for photosynthesis was understood.
Generations after generations led to the development of chloroplasts by the cyanobacteria due to this symbiotic relationships which developed into the chloroplasts.
The unique presence of the inner membrane and its components like the stroma, thyllakoids helped the organism to utilize water as the electron donor for photosynthesis like the present day eukaryotes. This is the main reason why cyanobacteria is considered as the ancestor for eukaryotes.
Answer:
This happens because viruses mutate and vary according to the environment they face. That is why different strains occur and appear every day, which must be updated in the vaccines, in order to have immunity up to date and keep up with the viral mutation without making us sick.
Explanation:
Viruses are acellular structures that do not have their own metabolism or replication method, it is because they must dominate and invade the human body so that its DNA or RNA is coupled to the human and this uses the human machinery to be able to replicate.
On the other hand, as infections occur and viruses appear, they can associate with bacteria forming bacteriophages, they can mutate within an organism that is infected by more than one viral infection and they can even adopt retrovirus mechanisms, which day by day. These new viruses are called as new strains, which evolve and will have to be coupled with vaccines.
Vaccines are a method of natural ACTIVE immunity, that is, part of the virus is inoculated, so that it generates the formation of a specific antibody in the body.
Answer:
of diffusion
Explanation:
Molecules move down a concentration gradient without the need to use energy. This means they move from a high concentration to a low concentration. This occurs across a semi-permeable membrane, like the cell membrane, by simple diffusion.
