The Following Questions Refer to the Description and Table 28

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
$$\begin{array} { l l } \text { Material } & \text { Specific Gravity } ( \mathrm { kg } / / \mathrm { m }^{3} ) \\\text { Pure water } & 1000 \\\text { Seawater } & 1026 \\\text { Hydrated silica } & 2250 \\\text { Liquid laminarin } & 1500 \\\text { Diatom oil } & 910\end{array}$$
-Some protists, formerly united as the "amitochondriate" clade, have recently been shown to be rather diverse. Some of them possess neither mitochondria nor mitochondrial genes (and have been classified as fungi) . Others possess no mitochondria, but do have mitochondrial genes in their nuclear genome. Still others have modified mitochondria (viz. mitosomes or hydrogenosomes) . Which statement(s) represent(s) consequences of these recent findings?
1) The amitochondriates do not comprise a True clade.
2) The "amitochondriate hypothesis" concerning the root of the eukaryotic tree has been strengthened.
3) Just as there is a diversity of cyanobacterial descendants among eukaryotes, so too is there a diversity of alpha-proteobacterial descendants among the eukaryotes.
4) If the amitochondriate organisms continued to be recognized as a taxon, this taxon would be polyphyletic.
5) Horizontal gene transfer involving mitochondrial genes has occurred in some amitochondriate organisms.

A) 1 only
B) 1 and 4
C) 2 and 3
D) 1, 3, and 5
E) all except 2

Correct Answer:

Verified

Unlock this answer now
Get Access to more Verified Answers free of charge

Access For Free