Disturbances to an ecosystem, such as fires and floods, are often seen as negative. Describe a situation where
regular disturbances are not only beneficial, but are required to sustain the ecosystem.

A biological community in which association takes place between the organisms and their physical surroundings is termed as an ecosystem. It can also be defined as an association between the nonliving and living components found within the environment. A particular geographical region, which is specified for the species thriving within it is known as a biome.  

A branch of science, which deals with the natural procedures that comprise fire within an ecosystem and the ecological influences it imparts, the association between the biotic and the abiotic constituents of an ecosystem with the fire, and the role played by fire within an ecosystem is termed as a fire ecology.  

Different kinds of ecosystems like savanna, prairie, coniferous forests and chaparral have originated by the contribution of the fire, which plays an essential role in the renewal and vitality of the habitat. Different kind of plant species needs the assistance of fire to establish, to reproduce, or to germinate. In case, if the suppression of wildfire takes place, it will eventually result in the eradication of various plant species and the animals that rely upon them.  

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.