Free Biodiversity and Variety of Life MCQs with Answers

1431. The coelom is a cavity lined by:

• A. Mesoderm
• B. Epiderm
• C. Endoderm
• D. Ectoderm

Explanation: The coelom is a fluid-filled cavity which is lined by the mesoderm. It is present in between the gastrointestinal tract and the body wall. An organism that has a fluid filled cavity lined by the mesoderm are called coelomates.Roundworms have a cavity which is not lined by the mesoderm, thus they are known as pseudocoelomates. Those organisms that lack a fluid filled cavity are called acoelomates.

1432. It is an endoparasite of humans, cattle, and pigs that completes its life cycle in two hosts:

• A. Tapeworm
• B. Liver fluke
• C. Aurelia
• D. Planaria

Explanation: This belongs to phylum platyhelminthes, class Cestoda, being exclusively endoparasite. The primary host of tapeworm is human and the secondary host is pig. The most common way to pick up a tapeworm is by eating undercooked meat. If pigs eat the infected feces containing eggs, the eggs hatch and the larvae form into cysts that make their way into the animals' muscles.

1433. A parasite living inside the body of the host is called:

• A. Ectoparasite
• B. Facultative parasite
• C. Obligate parasite
• D. Endoparasite

Explanation: Endoparasites are parasites that live in the tissues and organs of their hosts, such as tapeworms, flukes, and protozoans of vertebrates.

1434. During development, in an animal, the mesoderm layer gives rise to:

• A. Nervous System
• B. Muscular and skeletal system
• C. Alimentary canal lining
• D. Mouth

Explanation: The mesoderm layer contributes to the development of the skeleton (bone and cartilage) and the muscular system. Mesodermal cells differentiate into various types of connective tissues, which include those forming the skeleton and muscles.

1435. Polymorphism is a characteristic feature of:

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

Explanation: Polymorphism is a notable feature of cnidarians. Many cnidarians have multiple forms within their life cycle, including the polyp and medusa stages in some species.

1436. Which of the following is not a characterstics feature of tapeworm?

• A. Each body segment has two sets of male and female reproduction organs
• B. The digestive tract develops from endodermal cells in the embryo
• C. The body can be cut into two parts, which are mirror images of each other, in one plane only
• D. None of the above

Explanation: Based on the explanations provided, the correct answer to the question is option A) Each body segment has two sets of male and female reproductive organs.

1437. Which of the following characteristic belongs to acoelomates?

• A. Absence of mesoderm
• B. Absence of brain
• C. Coelom that is incompletely lined with a mesoderm
• D. Solid body without a cavity surrounding internal organs

Explanation: This is the correct characteristic of acoelomates. Acoelomates are organisms with a solid body plan, meaning they lack a fluid-filled body cavity like a coelom that surrounds their internal organs. Instead, the space between the outer body wall and the internal organs is filled with mesodermal tissue, which is often densely packed, giving them a solid appearance.

1438. The venous flower basket is also known as which of the following?

• A. Sycon
• B. Leucosolenia
• C. Spongilla
• D. Euplectella

Explanation: "The explanation for this question will be added soon!".

1439. The option that CORRECTLY identifies the class, type of coelom and organisation of germinal layers in leech is

• A. A
• B. B
• C. C
• D. D

Explanation: Leeches belong to class hirudinea, are ceolomates and triphloblastic. So option A is correct. All other options are incorrect.

1440. The characteristic of prototherians that provides an evidence of evolution of mammals from reptiles is that they have I

• A. webbed toes
• B. thick fur on their bodies
• C. mammary glands to feed their new-borns
• D. the same opening for excretion and reproduction

Explanation: The characteristic of prototherians that provides evidence of mammalian evolution from reptiles is the presence of a cloaca. This is a single opening used for both excretion and reproduction, a feature they share with reptiles, suggesting an evolutionary link. In contrast, most other mammals have separate openings for these functions.Webbed toes and thick fur are not indicative of reptilian ancestry. Mammary glands, although fundamental to mammals, do not establish an evolutionary connection to reptiles, as they are a distinctive development of mammals.