Level: F.Sc (Pre-Engg)
Class: 1st Year
Board: Punjab Textbook Board
Chapter 7: Kingdom Protoctista or Protista
Type: Short Questions
Author: Kiran Mehtab
PDF Size: 2 MB
Differentiate between diatoms and dinoflagellates.
The cell wall of each diatom consists of two shells that overlap where they fit together, much like a Petri dish. Silica is deposited in the shell, and this glass-like material is laid down in intricate (complex) patterns. While dinoflagellates are mostly unicellular. Their cells are often covered with shells of interlocking cellulose plates impregnated with silicates.
What are foraminiferans? Give their importance.
These marine protozoans produce shells (or tests). Tests of foraminifera are made of calcium. The shells or tests contain pores through which cytoplasmic projections can be extended. These cytoplasmic projections form a sticky interconnected net that entangles prey. Foraminiferans of the past have created vast limestone deposits.
What are dinoflagellates? or Write down two characteristics of dinoflagellates.
Dinoflagellates are mostly unicellular, animal-like protists. Their cells are often covered with shells of interlocking cellulose plates impregnated with silicates.
On what principle protists are grouped together?
Although some have multiple cells, most protists are one-celled or unicellular organisms. These cells have a nucleus and are enclosed by a cell membrane. For this reason, protists are often grouped either in the “animal-like protists” group, “plant-like protists” group, or the “fungus-like protists” group.