Free Biodiversity and Variety of Life MCQs with Answers

1211. Which one of the following is not a feature of the nervous system of Planaria?

• A. Neurons are differentiated into sensory, motor, and associative neurons
• B. Nerves are present
• C. No specialized sensory organs are present
• D. All of the above options are correct

Explanation: OPTION A: In Planaria, there is a differentiation of neurons into sensory associative and motor neurons. In Planaria, associative neurons are present in the brain and longitudinal nerves. Sensory neurons carry impulses to the 'brain' or nerves and motor neurons carry impulses from the central nervous system to different parts of the body.OPTION B: There are definite nerves, the longitudinal and lateral in Planaria.OPTION C: In Planaria at the anterior region, sense organs in the form of eyes and chemoreceptors are present. The receptor cells sensitive to pressure and touch-are present in Planaria. Hence, C is the correct option.

1212. Which of the following systems is not segmentally arranged in annelids?

• A. Excretory system
• B. Digestive system
• C. Circulatory system
• D. Nervous system

Explanation: The system that is not segmentally arranged in annelids is the circulatory system (option c). Other systems like the digestive, nervous, and excretory systems often exhibit segmental repetition in these organisms.

1213. Which of the following is an incorrect difference between a Shark and a Whale?

• A. A shark's heart has only one chamber whereas a whale's heart has two chambers
• B. Shark gills are not covered by operculum whereas those in a whale are
• C. Sharks do not possess a swim bladder whereas whales do
• D. Sharks have placoid scales on their skin whereas whales don't

Explanation: OPTION A: The heart of a shark has two chambers: an atrium (also known as the auricle) and a ventricle. The heart of a whale heart has four chambers. There are two auricles and two ventricles. Hence, A is the correct option. OPTIONS B, C, and D have a correct difference between a shark and a whale.

1214. Which of the following systems is well-developed in acoelomates?

• A. Excretory
• B. Nervous
• C. Transport
• D. Both options A and B are correct

Explanation: Acoelomates have complex nervous systems and excretory systems.

1215. Sub-kingdom parazoa inlcudes:

• A. Annelida
• B. Cnidaria
• C. Porifera
• D. Protozoa

Explanation: Animals included in phylum Porifera are Parazoans because they do not show the formation of true tissues (except in class Hexactinellida).

1216. Chitinous Setae are the locomotory organs of annelids which are present on?

• A. Cell wall
• B. Prostomium
• C. Nucleolus
• D. Parapodia

Explanation: The correct answer is d) Parapodia. Parapodia are fleshy, paddle-like structures that extend from the sides of the body segments in many annelids. They are specialized for locomotion, respiration, and sometimes serve as gills. Chitinous setae are present on the parapodia, and they play a crucial role in helping the annelids move through their environment by providing grip and traction.

1217. Which is not a characteristic of triploblasts?

• A. They may be coelomate pseudocoelomate or acoelomate
• B. They are included in grade bilateria
• C. All of them have digestive systems
• D. All of them have blood vessels

Explanation: Triploblasts have three germ layers: the outer (ectoderm), inner (endoderm), and middle (mesoderm). This means that they are grade B bilaterians. They are further divided into acoelomate (no cavity), pseudocoelomate (false cavity-not in the middle), and coelomate (true cavity-formed by the splitting of mesoderm). They have a digestive system.

1218. Typically, spiders' blood is blue due to the presence of which of the following?

• A. Haemoglobin
• B. Hemerythrin
• C. Haemocyanin
• D. Both Options B and C are correct

Explanation: Spider's blood is blue due to the presence of hemocyanin. Haemocyanin, instead of having an atom of iron in its middle, has an atom of copper that binds oxygen. It absorbs all colors except blue, which it reflects, making blood appear blue.

1219. Which of the following statements about chordates is true?

• A. They are protostomes
• B. All chordates are vertebrates
• C. They lack a coelom
• D. Their anus forms from the blastopore

Explanation: Chordates are deustromes so the answer cannot be Option A. All vertebrates are chordates but not all chordates are vertebrates so the answer cannot be Option B. All chordates have a coelom so the answer cannot be Option C and their anus is formed first from blastopore so the answer is Option D.

1220. Which of the following is a diploblastic organism?

• A. Hydra
• B. Crabs
• C. Squid
• D. Earthworm

Explanation: Diploblastic organisms have two germ layers, for example, Cridaria. Hydra belongs to the phylum Cridaria and class Hydrozoa.