Compare your circulatory system to a busy street in a city or town.
discuss the types of deliveries and pick ups made by the circulatory
system and what other parts of the body make this possible.

City individuals -different cells. Group of individuals - Organ systems. City Road System- Circulatory system.

Explanation:

Any city has population. The individuals of the population can be considered as the cells that are present in a human body. As a city cannot be formed with individuals, the human body cannot survive without cells. These individuals will belong to different profession and they go to an organisation for doing various work.

These can be compared with the organ system of human body. These organ systems will be performing different functions. The network of any rod in a city can be compared with the circulatory system of human body. As it helps individuals to reach their home of any destination, the presence of arteries and veins can be compared with the highways and capillaries can be associated with side ways of the road system.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

po-215 i got it right on the quiz