What types of pigments are found in Rhodophyta and Chlorophyta?
Pigments found in Rhodophyta (red algae) are chlorophyll a, carotenes and phycoerythrin while in Chlorophyta (green algae) chlorophyll a, chlorophyll b, and carotenes.
How slime molds reproduce?
During unfavorable conditions, plasmodial slime mold forms resistant haploid spores by meiosis within stalked structures called sporangia. When conditions become favourable again, spores germinate into biflagellated or amoeboid, reproductive or swarm cells which unite to form diploid zygote. Zygote produces multinucleate plasmodium, each nucleus being diploid.
Give scientific name of plasmodial slime mold. Give its importance.
The scientific name of plasmodial slime mold is Physarum polycephalum. It has been used to study many fundamental biological processes such as: growth and differentiation, cytoplasmic streaming, the function of cytoskeleton.
Give characters of oomycotes or What are water molds?
Oomycotes (water molds) are close relatives of the fungi and have a similar structure, but are now regarded as more ancient group. Their cell walls contain cellulose, not chitin. Their hyphae are aseptate (without cross walls). Oomycotes include a number of pathogenic organisms, including downy mildew Phytophthora infestans.
What are actinopods.
These are marine protozoans which produce shells (or tests). Tests of actinopods are made of silica. The shells or tests contain pores through which cytoplasmic projections can be extended. These cytoplasmic projections form a sticky, interconnected net that entangles prey.
What are limestone deposits? How they are formed?
Foraminiferans of the past have created vast limestone deposits. The pyramids of Egypt were built of foraminiferal limestone. Limestone is formed under reasonably deep marine conditions from the gradual accumulation of minute calcite (calcium carbonate) sheils of foraminifera and other organisms (corals).
Write two characters of Zooflagellates, or Give the examples, form and mode of locomotion in Zooflagellates or What are zooflagellates?
These protists are mostly unicellular (a few are colonial) organisms with spherical or elongated bodies, and a single central nucleus. They possess from one to many long, whip-like flagella that enable them to move. Flagellates move rapidly, pulling themselves forward by lashing flexible flagella, that are usually, located at the anterior end. Examples are Trypanosoma, Trichonymphas, choanoflagellates.
What are diatoms? Give their importance.
A single-celled alga which has a cell wall of silica. Silica is deposited in the shell, and this glasslike material is laid down in complex patterns. Diatoms are the major producers in the aquatic (marine and freshwater) ecosystems because of their extremely large numbers. Diatoms are very important in aquatic food chains.