Organization of Life

This question comes from nyslivingenvironment.net, the August 2010 exam



What do you guys think? I'll give you some time... here's some thinking music for ya'll. Hopefully you don't need all that time :-P

If you chose answer (2), you chose correctly my friend. It's actually pretty amazing, and pretty clever, that every single somatic (body) cell in the human body has the same genetic information (same exact DNA), but just differs in the expression (activation) of that information, depending on what type of cell it is. Think of it this way. All of the cells in your body (except gametes, which you shouldn't worry about now) use the same instruction booklet, and each cell has a whole copy of the booklet. However, your heart cells only use pages 5-6 of the book, while your lung cells only use pages 7-9. So while each cell contains the whole booklet, it only uses the part it needs to become/stay that specific type of cell.

With this in mind, answer (4) does not make sense, since heart and lung cells have the same amount of DNA molecules. Answer (1) is incorrect because it is only true for the lungs--the heart does not contain cells that make a hormone involved in respiration (breathing). Answer (3) is tricky because it seems similar to answer (2), the correct answer. But read closely...this answer talks about the "genetic code," which helps copy DNA bases and turn the message from DNA into protein (remember, DNA--->RNA--->Protein). Every cell uses the same code, not just one part of the code. It is the part of the DNA molecule used that changes between cells. Got it?

If you need more help, this site might provide a clearer explanation:
http://genetics.thetech.org/ask/ask4

And if you were wondering, yes, I did listen to that youtube video the whole time I made this post.

Birds of a Feather

This question is from the August 2008 Regents, from nyslivingenvironment.net. The correct answer here is (4), bright-colored males.

There is some important information that the question provides which we must take into account. For starters, "male offspring inherit their father's bright colors and long feathers." So, we know that dull-colored males (3) and bright-colored females (1) are not possible answers. That leaves dull-colored females (2) and bright-colored males (4). Read the question again. "Compared to earlier generations, future generations...will...have a greater proportion of _____." Dull-colored females does not make sense, because there will not be a GREATER number of these birds than before. If all females can only be dull, we will not see more dull females in the future. But, if "females usually pick the brightest colored males for mates," we will see a greater number of brightly colored male birds. Make sense?



Check out this video for a look at some of the exotic birds mentioned:
 http://www.youtube.com/watch?v=YTR21os8gTA

Take a look at the Birds-of-Paradise Project, it's pretty neat:
 http://birdsofparadiseproject.org/#!/2/The%20Birds