Question

Which of the following is UNTRUE about diatoms?

A. They are unicellular.
B. They attach themselves to algae.
C. They have beautiful glasslike cell walls.
D. They move by secreting ooze and sliding through it.

Answer 1

Which choices can you eliminate - what do you already know about diatoms?

Answer 2

I can eliminate B or C??

Answer 3

Okay great! So you have A and D left.

Answer 4

Diatoms, most of the time, ARE unicellular protists so that should point you to the correct answer.

Answer 5

It's impossible to know everything about diatoms of course, so maybe you can't say that they definitely don't ooze and slide - but by applying some basic informatino that you do know (unicellular, algae, silica walls, live in the ocean) you can eliminate the unfamiliar answer choices.

Answer 6

Diatoms are definitely unicellular. I agree with Kma, however, C sounds more like an opinion than a true fact. That would most likely be the untrue answer.

Diatoms attach themselves to other algae and they may secrete a substance to move about. There are scientific studies of large deposits of siliceous diatom ooze.

Answer 7

Hm that's a good point. C did sound kind of fishy ("beautiful" is most definitely subjective) but C seemed safer to me. I have no information about D, but intuitively, it doesn't seem likely because diatoms are generally free-floating in the ocean, right? That mode of movement doesn't seem to suit their lifestyle. From a test question perspective though, I can't imagine a test writer justifying C as the correct answer on a technicality - "the word beautiful is too subjective!" that would be pretty evil haha. Just my two cents, though.

Answer 8

Ive always found diatoms to be beautiful... as for the glass bit... not exactly, they are silica mostly.

http://www.daviddarling.info/images/diatoms.jpg

But yeah id go with C... mostly based on the subjective nature and the fact that they arent glass--but share the common element.

Answer 9

Update: after much searching, I've learned that diatoms can indeed move through ooze! Crazy, huh. Tough question!

"They are non-motile, or capable of only limited movement along a substrate by secretion of mucilaginous material along a slit-like groove or channel called a raphe."

http://www.ucl.ac.uk/GeolSci/micropal/diatom.html

Answer 10

If anyone is interested, I've attached a pdf file focused on the types of oozes formed from diatoms. And great find! @Kma230

Answer 11

Very interesting article; thanks for attaching it.

Answer 12

id go with C