Diversity in Living Organisms

Correct answer. Both are freshwater sponges. Phylum porifera consists of mainly marine animals living in deep seas but few species are also found in freshwaters e.g. spongilla. Marine animals/sponges belong to classes Calcarea and Hexactinellida while fresh water sponges are placed in class Demospongiae.

Correct answer. All of these are classes of phylum Porifera. Calcarea, Hexactinellida and Demospongiae are classes of phylum Porifera. Cnidaria is a separate phylum, Turbellaria is a class of phylum Platyhelminthes while Hirudinaria is Indian common leech.

Correct answer. It has a body temperature ranging from 77 - 98.6 degrees and this keeps changing with seasons. Warm-blooded creatures, like mammals and birds, try to keep the inside of their bodies at a constant temperature. They do this by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment but keep body temperature fixed or same throughout the year e.g. 37 degrees celsius in humans. However, Echidnas maintain a range of body temperatures which usually lies between 77 and 98.6 degrees Fahrenheit and have difficulty cooling down.There are some mammals who are not able to tolerate extreme conditions so they show different adaptations e.g. hibernation, to adjust in such conditions without compromising on their thermoregulation.

Correct answer. Doliolum, Pyrosoma and Amphioxus all are chordates. Chordates are the animals, which possess a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail for at least some period of their life. The phylum chordataU includes the subphyla Vertebrata, including mammals, fish, amphibians, reptiles, birds; Urochordata/ Tunicata, (including Herdmania- sea squirts, Doliolum, Pyrosoma)and Cephalochordata, comprising the lancelets(Branchiostoma). The phylum Hemichordata including the acorn worms was earlier considered fourth chordate subphylum, but it now is usually treated as a separate phylum. It, along with the phylum Echinodermata, including starfish, sea urchins, and sea cucumbers are nearest relatives of chordates.

Correct answer. Peripatus belongs to Onychophora Peripatus is an (onychophore) invertebrate, which looks like a caterpillar. However, on closer examination the external appearance is more like an annelid (earth) worm. In fact, it is also called a 'velvet worm'. The head is continuous with the body. The eyes probably distinguish only light and dark. The outer cuticle is thin and flexible, with no external segmentation (divisions). Peripatus is commonly called velvet worm.Velvet worms share a number of characteristics with both phylum Annelida (segmented worms) and phylum Arthropoda. Some authors place onychophorans in a subphylum within the phylum Arthropoda, but others regard the Onychophora as a separate phylum.

Pyrrolysine is an ɑ-amino acid that is used in the biosynthesis of proteins in some methanogenic archaea and bacteria.

Amoeba exhibits holozoic nutrition, which means it engulfs solid food particles. This is the same mode of nutrition as higher organisms. 'Heterozoic' is not a standard biological term, and 'monozoic' does not apply to single-celled organisms.

A bacterium bearing flagella all over its surface is called peritrichous.

All three kingdoms mentioned have cell walls. Monera (bacteria) have peptidoglycan cell walls, fungi have chitin cell walls, and plantae have cellulose cell walls. Therefore, all of them possess organisms with cell walls.

Bacterial DNA lacks histones, which are proteins that help package DNA in eukaryotes. Bacteria do contain nucleic acids (DNA/RNA) and polyamines, but histones are absent in their nuclear material.

Lichens are symbiotic organisms formed by the association of algae (photosynthetic partner) and fungi (structure and protection). The algae provides food through photosynthesis while fungi provides minerals and shelter.

Protozoans are primarily classified based on their locomotory organelles - flagella, cilia, or pseudopodia. Size, shape, and reproduction methods vary within groups but locomotory structures are the fundamental basis of classification.

All three options are eukaryotes. Plants have true nuclei and organelles. Kingdom Protista consists of eukaryotic organisms. Yeast is a fungus, which is eukaryotic. Therefore, all are eukaryotes.

Protozoa are single-celled eukaryotic organisms that move using specialized structures. Different groups of protozoa use different locomotory organs: some use whip-like flagella for propulsion, others use hair-like cilia that beat in coordinated waves, and amoeboid protozoa extend cytoplasmic projections called pseudopodia to crawl. Since various protozoa use each of these structures depending on their classification, all options are correct.

Yeasts are eukaryotic microorganisms classified within the Kingdom Fungi. They reproduce asexually by budding or fission and obtain nutrients through absorption. Unlike bacteria which are prokaryotic, viruses which are non-living, and protists which are a separate kingdom of mostly unicellular eukaryotes, yeasts share all defining fungal characteristics including cell walls made of chitin and inability to perform photosynthesis.