Explanation:
The effects of gamma radiation are investigated by studying plant germination, growth and development, and biochemical characteristics of maize. Maize dry seeds are exposed to a gamma source at doses ranging from 0.1 to 1 kGy. Our results show that the germination potential, expressed through the final germination percentage and the germination index, as well as the physiological parameters of maize seedlings (root and shoot lengths) decreased by increasing the irradiation dose. Moreover, plants derived from seeds exposed at higher doses did not survive more than 10 days. Biochemical differences based on photosynthetic pigment (chlorophyll a, chlorophyll b, carotenoids) content revealed an inversely proportional relationship to doses of exposure. Furthermore, the concentration of chlorophyll a was higher than chlorophyll b in both irradiated and non-irradiated seedlings. Electron spin resonance spectroscopy used to evaluate the amount of free radicals induced by gamma ray treatment demonstrates that the relative concentration of radiation-induced free radicals depends linearly on the absorbed
Evolution is all about the
process of inheriting characteristics within a population change over
generation.
Only inherited traits
differences that can be passed on are acted upon evolution.
<span>In the study, the humans
select desirable traits that can be passed from one generation to another.</span>
Answer:
- Independent variable: Car weight (car + block with a mass of 10 grams)
- Dependent variable: Speed (the time the car takes to descend the ramp)
Explanation:
As you can see in the question above, Shawn wants to check the speed that a car takes when going down a ramp, related to the weight of this case, that is, he wants to know the influence of the weight that the car presents, in its speed in going down a ramp.
In this type of experiment, we can consider the weight that the car presents as the independent variable. This is because independent variables are those that influence a result within the experiment. They happen without the influence of another variable and are factors that impose changes in the analyzed system.
The dependent variable, however, is the car's speed down the ramp. This is because the dependent variables are those that need and are influenced by the independent variable, to achieve a result that can be measured and analyzed.
I believe B is the answer..
