Answer:
D. Because science only uses facts that are proven 100% true through the use of variables.
Explanation:
All the knowledge we read is science books are not merely some observed facts but the result of a systematic scientific methodology through which facts are tested. Science only gives us that knowledge as facts which is proven 100% true through the use of variables.For example: if a scientist has studied the effect of salt stress on the growth of plants and he got the results in form of graphs which show that growth of salt treated plants in very less than normal plants. Then he needs to draw conclusion after consulting relevant previous experiments and say that salt stress hinders growth and why? with reasonable logic.
Variables are the things hat he changes like environmental conditions in previous example to see that in changed conditions plant is showing changed behavior. This way a scientist strengthens his results. Therefore, we can say that whatever knowledge we get through science is proven 100% true through the use of variables.
Hope it helps!
Answer:
exposure to ultraviolet radiation is a correct answer.
Explanation:
Ultraviolet light exposure results in the formation of pyrimidine dimers. Ultraviolet radiation damage the DNA by resulting in chemical changes.
Ultraviolet radiation is absorbed by the pyrimidine bases( cytosine and thymine in DNA) and result in the formation of covalent bonds between the succeeding bases.
The formation of the pyrimidine dimers results in the distortions of DNA helix and disrupt the base-pairing during the replication of DNA which results in a mutation.
Answer:
Water sample showing pink/purple color is an error.
Explanation:
Biuret is a blue color reagent that changes its color to pink/purple whenever it detects protein in a sample. Water don't contain proteins so it should not show pink/purple color instead it should maintain the blue color. Food items generally contain proteins so it show pink/purple color but it showed blue color.
Error might have caused by wrong marking of the samples, test tube marked with Water might contain a mystery food while Mystery food tube might contain water.
The basics would be that you'd need to find out if they could exchange genetic information. If not, they couldn't be considered part of one species. Set-up 2 artificial environments so both groups would produce pollen at the same time. Fertilise both plants with the other's pollen. Then fertilise the plants with pollen from their own group.
Count the number of offspring each plant produces.
If the plants which were fertilised by the opposite group produce offspring, they are of the same species. You can then take this further if they are of the same species by analysing if there is any difference between the number (and health) of offspring produced by the crossed progeny and by the pure progeny. You'd have to take into account that some of them would want to grow at different times, so a study of the progeny from their first sprout until death (whilst emulating the seasons in your ideal controlled environment). Their success could then be compared to that of the pure-bred individuals.
Make sure to repeat this a few times, or have a number of plants to make sure your results are accurate.
Or if you couldn't do the controlled environment thing, just keep some pollen one year and use it to fertilise the other group.
I'd also put a hypothesis in there somewhere too.
The independent variable would be the number of plants pollinated. The dependant variable would be the number of progeny (offspring) produced.
Answer:
Soil Erosion
Explanation:
Basically, tillage breaks soil up, destroying its overall structure. It encourages surface runoff and therefore soil erodes more easily. In some cases soil erosion is beneficial, but in most cases, it is not. Tillage has also been found to cause the emissions of more toxic gases such as N20.
