Question

Slimy green patches in ponds or in stagnant water is
A. Fungi
B. Bryophytes
C. Bacteria
D. Algae

Answer 1

Microorganisms that exist as unicellular, multicellular, or cell clusters are microscopic organisms which appear in patches. Stagnant water means standing or undisturbed water.

Complete answer:
Now we will see each of the options separately and in brief about them.
Fungi are multicellular eukaryotic organisms. Fungi are commonly heterotrophs (cannot make their own food). Fungi lack chlorophyll and can not carry out photosynthesis as a result.
Bryophytes are a group of plant species which reproduce instead of flowers or seeds but through spores. In damp conditions, most bryophytes are present and consist of three types of non-vascular land plants: mosses, hornworts, and liverworts.
Bacteria, which are neither plants nor animals, are single-cell species. Typically they weigh a few micrometres in length and live in groups of millions together. In soil, water, plants, animals, nuclear waste, deep in the earth's crust, arctic ice and glaciers, and hot springs, bacteria can be contained.
Algae are eukaryotic species with no roots, stems, or leaves, but for photosynthesis, they have chlorophyll and other pigments. Multicellular or unicellular can be algae. These appear green in colour due to the presence of chlorophyll. They appear as slimy green patches on the water since they are often seen in the water or humid areas are of multiple colours.
So from the above discussion, it is clear that algae are slimy green patches which are present in water.

So the correct answer is option D algae.

Note: Algae, such as red, brown, and green, have been grouped into major colour-based categories. The colours represent the various pigments of a chloroplast, such as chlorophylls, carotenoids, and phycobiliproteins.