Answer: C. Stream elevation
Stream velocity is the speed of water in a stream. It can be measured in meters per second or feet per second. Stream velocity is highest in the mid stream and lowest along the bottom of the stream. Stream discharge depicts the flow of water from it's source of origin. Stream gradient indicates difference in pressure levels between different water layers. Channel size is the width of water surface acquired by the water body. Stream elevation is the rise in the superficial layer of water. Stream discharge, stream gradient and channel size all influence the stream velocity as they are related to the flow of water. Stream elevation does not influence flow of water hence, does not influence stream velocity.
Answer:
The correct answers are- a) In the deformed mice, somatic cells but not germ cells were mutated and d) The toxic chemical affects development but is not mutagenic.
Explanation:
Mutation in the somatic cells do not pass in the offsprings and the only mutation in the germ cells can pass to the offspring because offspring are produced by the fertilization between different germ cells. Somatic cell mutation can only cause deformation in individuals but their offspring will be like normal offsprings.
The other cause may be that the toxic chemical used don't cause any mutation but just affect the development of mice so in this case genetic material will remain in normal state in deformed mouse and they will able to produce normal offsprings. So the right answer is a and d.
