$\text{\blue{MAKE CONNECTIONS}}$ In Concept 20.2, you learned about genome-wide association studies. Explain how these studies use the systems biology approach.

Compare and contrast linkage analysis and genome-wide association studies. How are they similar? How are they different?

What kind of diseases are studied using genome-wide association studies?

Discuss why a genetic disease might have a particular age of onset. Would an infectious disease have an age of onset? Explain why or why not.

Using sickle cell disease as an example, describe the similarities and differences between the terms genetic disease and molecular disease. How are molecular or genetic diseases different from diseases that are caused by an infectious organism such as a bacterium?

What is the main purpose of genome-wide association studies (GWAS)? How can information from GWAS be used to inform scientists and physicians about genetic diseases?

What is pinocytosis, and what is phagocytosis?

The difference between pinocytosis and receptor-mediated endocytosis is that:

A) Pinocytosis brings liquid with dissolved nutrients into the cell, but receptor-mediated endocytosis brings in other molecules as well.

B) Pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area.

C) Pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.

D) Pinocytosis requires cellular energy, but receptor-mediated endocytosis does not.

E) Pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.

What is crenated or crenation?

Explain why an animal cell will eventually burst when placed in a hypotonic solution. If a cell had large numbers of aquaporins in its membrane, would it be able to avoid bursting by allowing water to rapidly leave through these channels?

Cerebrospinal fluid (CSF) shunts are typically placed in which children?

Below are the amino acid sequences (using the single-letter code; see Figure 5.14) of four short segments of the FOXP2 protein from six species: chimpanzee (C), orangutan $(\mathrm{O})$, gorilla $(\mathrm{G})$, rhesus macaque $(\mathrm{R})$, mouse $(\mathrm{M})$, and human $(\mathrm{H})$. These segments contain all of the amino acid differences between the FOXP2 proteins of these species.

1. ATETI... PKSSD... TSSTT... NARRD
2. ATETI...PKSSE...TSSTT...NARRD
3. ATETI...PKSSD...TSSTT...NARRD
4. ATETI...PKSSD...TSSNT ...S ARRD
5. ATETI...PKSSD...TSSTT...NARRD
6. VTETI...PKSSD...TSSTT...NARRD

Use a highlighter to color any amino acid that varies among the species. (Color that amino acid in all sequences.)

(a) The $\mathrm{C}, \mathrm{G}, \mathrm{R}$ sequences are identical. Which lines correspond to those sequences?

(b) The $\mathrm{H}$ sequence differs from that of the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ species at two amino acids. Underline the two differences in the $\mathrm{H}$ sequence.

(c) The $\mathrm{O}$ sequence differs from the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ sequences at one amino acid (having $\mathrm{V}$ instead of $\mathrm{A}$ ) and from the $\mathrm{H}$ sequence at three amino acids. Which line is the $\mathrm{O}$ sequence?

(d) In the $M$ sequence, circle the amino acid(s) that differ from the $C, G, R$ sequences, and draw a square around those that differ from the $\mathrm{H}$ sequence.

(e) Primates and rodents diverged between 60 and 100 million years ago, and chimpanzees and humans about 6 million years ago. What can you conclude by comparing the amino acid differences between the mouse and the $C, G, R$ species with those between the human and the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ species?

Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity? (A) gene duplication (B) alternative splicing (C) exon shuffling (D) random point mutations

Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity?

a. gene duplication

b. RNA splicing

c. exon shuffling

d. random point mutations