Extracellular RNAs are abundant in human bodily fluids, but there is currently very little evidence for their potential functions in the body. Speculate on the roles that exRNAs might play in human biology.

What, if anything, causes each of the stages of decline in the Four Ages? Does a human action precede each stage of degeneration, or is the decline beyond human control? Explain.

How do positive and negative selection techniques contribute to the development of GM crops?

Iron is important in the diet for the development of
a. bones.
b. vision.
c. blood.
d. hair.

How is human activity affected by specific climate regions? Using the maps in the unit atlas, choose a climate region and provide an example of how it influences human activity.

Explain how the understanding of atomic emission spectrum led to development of the atomic theory.

The development of cancer is a multistep process, requiring mutations in several cancer-related genes.

Analyze Information How did the development of the interstate highway contribute to postwar prosperity?

Discuss which factors are involved in vaccine development and new strategies for developing vaccines.

Describe your opinions regarding the recycling of plastics versus the development of plastics that are biodegradable.

In the food chain, grass $\rightarrow$ antelope $\rightarrow$ human $\rightarrow$ lion, the human is what?

A) secondary consumer
B) tertiary consumer
C) primary consumer
D) producer

Clearly, all humans have variations in their DNA sequences. How is it possible to sequence the human genome if every individual is unique? How was the diversity of the human genome addressed?

In a study, a cancerous tumor was found to have a volume of

$$f(t)=1.825^3\left(1-1.6 e^{-.4196 t}\right)^3$$

milliliters after t weeks, with t>1. (Source: Growth, Development and Aging.)

(a) Sketch the graphs of f(t) and $f^{\prime}(t)$ for $1 \leq t \leq 15$. What do you notice about the tumor's volume?

(b) How large is the tumor after 5 weeks?

(c) When will the tumor have a volume of 5 milliliters?

(d) How fast is the tumor growing after 5 weeks?

(e) When is the tumor growing at the fastest rate?

(f) What is the fastest rate of growth of the tumor?

Which is a vertical development cloud?

A. cumulonimbus

B. cirrus

C. stratus

D. altocumulus