The Following Questions Refer to the Description and Table 28

question 22

Multiple Choice

The following questions refer to the description and Table 28.1 below.
Diatoms are encased in Petri-plate-like cases (valves) made of translucent hydrated silica whose thickness can be varied. The material used to store excess calories can also be varied. At certain times, diatoms store excess calories in the form of the liquid polysaccharide, laminarin, and at other times, as oil. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment.
Table 28.1: Specific Gravities of Materials Relevant to Diatoms
$$\begin{array} { l l } \text { Material } & \text { Specific Gravity } ( \mathrm { kg } / / \mathrm { m }^{3} ) \\\text { Pure water } & 1000 \\\text { Seawater } & 1026 \\\text { Hydrated silica } & 2250 \\\text { Liquid laminarin } & 1500 \\\text { Diatom oil } & 910\end{array}$$
-A certain unicellular eukaryote has a siliceous (glasslike) shell and autotrophic nutrition. To which group does it belong?

• A)dinoflagellates
• B)diatoms
• C)brown algae
• D)radiolarians
• E)oomycetes

---

Definitions:

Synaptic Vesicles

Synaptic Vesicles are small sacs within a neuron that store neurotransmitters, which are released into the synaptic cleft to transmit signals to other neurons.

Neurotransmitters

Chemical messengers in the brain and body that transmit signals across nerve synapses to influence physiological functions and behavior.

Intense Impulses

Strong, spontaneous desires to act in a certain way, often without foresight or consideration of consequences.

Evolutionary Psychology

The branch of psychology that studies the ways in which adaptation and natural selection are connected with mental processes and behavior.