Tutor profile: Yoav K.

What's the difference between Wernicke's aphasia and Broca's aphasia?

Wernicke's area and Broca's area are both related to language and found only on the left hemisphere of the brain. Wernicke's area helps understand and generate meaningful speech, while Broca's area helps control the physical movements related to producing speech. An aphasia, or language impairment, can result from damage to either area in the brain. So, Wernicke's aphasia means a patient isn't able to understand or produce coherent speech (regardless of ability to make the correct muscle movements to speak), and Broca's aphasia means a patient can't control speech motions (regardless of ability to think of a meaningful response).

What's the difference between prokaryotic and a eukaryotic cells?

In basic terms, prokaryotic cells are simple and eukaryotic cells are complex. One important difference is the presence of membrane-bound organelles: in prokaryotes, the parts of the cell mostly float around the cytoplasm, while in eukaryotes, some parts are free while other parts are encapsulated by internal membranes that help organize the inside of the cell. Another important difference is that prokaryotic DNA (genetic code) is not tightly wound up and is in fact in a single long chain; eukaryotic DNA, though, is usually split into chunks called "chromosomes" that are extremely tightly wound up. There are many other differences between these two types of cell, but the two listed here are definitely important to remember!

Write the slope-intercept form of the line that goes through the points (0,3) and (1,9).

Our template for slope-intercept form is always y=mx+b. Because x and y are variables, all we need to do is find the constants, m and b, and plug them in! Let's start by finding m, which is the "slope" of the line. We have a formula for slope: m=(y2-y1)/(x2-x1). Remember, x1 represents the x-value for the first point, y1 represents the y-value for the first point, x2 represents the x-value for the second point, and y2 represents the y-value for the second point. Substituting into the slope formula above, we get m=(9-3)/(1-0)=6/1, or just 6. Therefore, our slope is 6! Now, let's find b, or our y-intercept (where the line crosses the y-axis on a graph). To find b, we simply plug in everything we already know into the slope-intercept equation and solve for b! We plug in 6 for m, and either point's x-value and y-value for x and y. y=mx+b 3=(6)(0)+b 3=0+b 3=b There we have it: b=3! To finish off the problem, all we have to do is plug m=6 and b=3 into our original template. Therefore, y=6x+3 is our final answer!