The answer will be F planet A orbits it’s star faster than planet B
A. <span>Exposure to an antigen
Exposure to viruses and antigens led to the foundation of modern vaccination. Vaccination introduces an antigenic material that helps the ability of the immune system to adapt a specific pathogen, therefore leading to a long-term immunity.</span>
In a hydra, digestion is completed intracellularly.
Hence option (a) is correct.
Small, freshwater organisms of the phylum Cnidaria and class Hydrozoa are grouped under the genus Hydra. They are indigenous to temperate and tropical climates.
The digestion takes place intracellularly in Hydra.
Because of their ability to regenerate and the fact that they don't appear to age or experience old age, hydra have drawn the attention of biologists.
Like most other cnidarians, hydras have a pretty straightforward digestive system.
They have a two-way digestive system, which differs from mammals in that food and waste enter and exit through the same aperture. A "blind gut" is the name for this configuration.
The center of the hydra's body is occupied by its digestive tract.
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Water because hydro means water
A phenomenon, in the scientific context, is an observable event that can range from a seasonal hazard to a technological issue. For a scientist, a phenomenon is an observable event.
