Test: Diversity in Living Organisms- 1 - UPSC MCQ

R. H Whittaker proposed  the five kingdom classification. The five kingdom classification are - Monera, Protista, Fungi, Plantae  and  Animalia.

The correct option is A.
Cell aggregate body plan Cells are loosely arranged and do not organise to form tissues, e.g., Sponges.

Phylum Pseudocoelom
The phylum in which pseudocoelom is present is Aschelminthes. Here is a detailed explanation:
1. Coelenterata:
- Pseudocoelom is not present in the phylum Coelenterata.
- Coelenterates, such as jellyfish and sea anemones, have a simple body plan without a true body cavity.
2. Annelida:
- Annelids, such as earthworms and leeches, have a true coelom, which is a fluid-filled body cavity lined with mesoderm.
- They do not have a pseudocoelom.
3. Aschelminthes:
- Aschelminthes, also known as the "roundworms," possess a pseudocoelom.
- The pseudocoelom is a body cavity that is not fully lined with mesoderm, but rather only partially lined.
- Examples of organisms in this phylum include nematodes, rotifers, and hookworms.
4. Mollusca:
- Mollusks, such as snails, clams, and squids, have a true coelom.
- They do not possess a pseudocoelom.
Therefore, the correct answer is option C: Aschelminthes.

Flatworms are found in the phylum Platyhelminthes.
Explanation:
- Flatworms belong to the phylum Platyhelminthes, which is a group of soft-bodied, unsegmented worms.
- They are characterized by their flattened shape, hence the name "flatworms."
- Flatworms can be found in various environments, including freshwater, marine, and terrestrial habitats.
- They exhibit a wide range of adaptations and can be free-living or parasitic.
- Some common examples of flatworms include planarians, tapeworms, and flukes.
- Flatworms have a simple body structure with a single opening serving as both the mouth and anus.
- They lack a circulatory system and a respiratory system, relying on diffusion for gas exchange.
- Flatworms exhibit a variety of reproductive strategies, including both sexual and asexual reproduction.
- They play important ecological roles as decomposers, predators, and parasites in various ecosystems.
In conclusion, flatworms are found in the phylum Platyhelminthes, which is a diverse group of worms with a flattened body shape. They can be found in different habitats and exhibit a range of adaptations and reproductive strategies.

Sea star, also called Starfish, any marine invertebrate of the class Asteroidea ( phylum Echinodermata) having rays or arms surrounding an indistinct central disk.
Despite their older common name they are not fishes.

C is the correct option.Protochordates are an informal category of animals (i.e.: not a proper taxonomic group), named mainly for convenience to describe invertebrate animals that are closely related to vertebrates. This group is composed of the Phylum Hemichordata and the Subphyla Urochordata and Cephalochordata.Balanoglossus is an example of Protochordates.

Chimera is a shark not a bony fish. 
Sharks and bony fish are two fish groups. Sharks  are cartilaginous fish. They have a cartilaginous skeleton. Bony fish have a skeleton made from calcified bones. Sharks and bony fish belong to the different classes.

Amphibians have a three-chambered heart - two atria and one ventricle. The mixing of oxygenated and deoxygenated blood is kept to a minimum due to the timing of the contractions between the atria. This is called an incomplete double circulatory system.

The syrinx is the vocal organ of birds. Located at the base of a bird's trachea, it produces sounds without the vocal folds of mammals. The sound is produced by vibrations of some or all of the membrana tympaniformis (the walls of the syrinx) and the pessulus, caused by air flowing through the syrinx. This sets up a self-oscillating system that modulates the airflow creating the sound. The muscles modulate the sound shape by changing the tension of the membranes and the bronchial openings.The syrinx enables some species of birds (such as parrots, crows, and mynas) to mimic human speech. Unlike the larynx of mammals, the syrinx is located where the trachea forks into the lungs. Thus, lateralization of bird songis possible and some songbirds can produce more than one sound at a time. Some species of birds, such as New World vultures, lack a syrinx and communicate through throaty hisses.

Mammals & birds are warm – blooded, which means that they can make their own body heat even when it is cold outside. Whether it is sunny and hot outside or there is a snowstorm and it is very cold, warm-blooded animals have body temperatures that usually stay the same.

The diaphragm is the only organ which only and all mammals have and without which no mammals can live.

 But they still have milk-producing mammary glands. They give birth to tiny babies, which then live in a special pouch on the mother and grow by suckling her milk. Based on all this, it seems clear that milk and breastfeeding are unique to the mammals.

The earthworm is made up of about 100-150 segments. The segmented body parts provide important structural functions. Segmentation can help the earthworm move. Each segment or section has muscles and bristles called setae. Explanation: The earthworm body is divided into ringlike segments (as many as 150 in L.terrestris. Some internal organs, including the excretory organs, are duplicated in each segment. Between segments 32 and 37 is the clitellum, a slightly bulged, discolored organ that produces a cocoon for enclosing the earthworm's eggs.

The clitellum is part of the reproductive system of clitellates, a subgroup of annelids which contains oligochaetes ( earthworms) and hirudineans        (leeches) . The clitellum is a thick, saddle like ring found in the epidermis of the worm, usually with a light - colored pigment.

Clitellum. The clitellum is a thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which the eggs are deposited. It is located near the anterior end of the body (around the 14th,  and 16th

D is the correct option.Setae are the 'S' shaped stiff bristles present on the complete body of earthworm except for the first, last and clitellar segments. These setae play an important function in locomotion.

The correct option is B.
The important structural components of a cell wall are:
Cellulose is an important component of plant cell walls that make the plant stems, leaves and branches rigid; they are present in the form of cellulose microfibrils (long fibre-like strands) in the inner layer of the primary wall.
Pectin is an essential polysaccharide present in the plant cell wall that allows the extension of a primary cell wall and in plant growth.
Hydroxyproline-rich glycoproteins form an important structural component of cell walls.
The rigidity and orientation of cellulosic microfibrils (structural element) help in cell expansion.
So, the correct answer is 'Microfibrils'.

 Plant cell contains an outer wall, plastids and a large central vacuole which are all absent in an animal cell. Animal cells have centrioles which are absent in plant cells.

The ripening fruits soften due to solubilization of pectate of middle lamella. The outer cell walls of fruits contain a substance called pectin. Pectin thickness the cell wall and provide strength. It also connects adjacent cells by providing an additional layer of pectin called Lamellae.