Free Biodiversity and Variety of Life MCQs with Answers

2701. Polychaeta have which of the following organs?

• A. Tentacles
• B. Palps
• C. Eyes
• D. Both B and C

Explanation: This is correct as polychaetes have sensory palps and they have well developed eyes with photoreceptors.

2702. Coelom that develops from the archenteron as outpouching is?

• A. Pseudocoelom
• B. Enterocoelom
• C. Schizocoelom
• D. Both a and b

Explanation: An enterocoelom is a true coelom that develops from the archenteron during embryonic development. In organisms that exhibit enterocoely, the coelom forms as outpouchings or cavities that pinch off from the archenteron and become surrounded by mesodermal tissue. This process is called enterocoely. Examples of organisms that develop an enterocoelom include echinoderms (e.g., sea stars) and chordates (including vertebrates).

2703. In most triploblasts after embryonic development the three layers are represented as?

• A. Separate layer of cells
• B. Structure formed from them
• C. Their function in body
• D. Structure associated with them

Explanation: 3 different structures are formed the 3 layers in triploblast after embryonic developement. These structures are known as ectoderm, mesoderm and endoderm.

2704. Which one of the following statements about all the four of Spongilla, leech, dolphin and penguin is correct?

• A. Penguin is homeothermic while the remaining three are poikilothermic
• B. Leech is a freshwater form while all others are marine
• C. Spongilla has special collared cells called choanocytes which are not found in the remaining three
• D. All are bilaterally symmetrical.

Explanation: Spongilla is a common, widely distributed fresh water sponge belonging to phylum porifera. Canal system in Spongilla is essentially of rhagon type with choanocytes restricted to small rounded chambers. It is not found in leeches, dolphins or penguins.

2705. Animals of grade radiata are:

• A. Diploblastic
• B. Acoelomate
• C. Triploblastic
• D. Pseudocoelomate

Explanation: Grade radiata animals, such as those in the phylum Cnidaria, are diploblastic, meaning they develop from two primary germ layers: the ectoderm and endoderm.

2706. In coelomate the layer that surround endoderm is:

• A. Coelomic Epithelium
• B. Ectoderm
• C. Visceral mesoderm
• D. Parietal Mesoderm

Explanation: In coelomates, the mesoderm splits to form the coelom. The visceral layer of mesoderm surrounds the endoderm (gut), while the parietal layer lines the body wall.

2707. Saclike digestive system is present in:

• A. Porifera
• B. Platyhelminthes
• C. Arthropoda
• D. Chordates

Explanation: Platyhelminthes has flat worms. They are triploblastic and have mouth which opens into a gut but no anus so their digestive system is termed as sac like.

2708. Which of the following is the exclusive character of mammals?

• A. Homeothermic
• B. Poikilothermic
• C. Hair
• D. Four chambered heart

Explanation: Hair is a defining characteristic of mammals. Most mammals have hair or fur covering some or all of their bodies. This feature distinguishes them from other animal groups.

2709. The best function of coelom is described as _.

• A. To increase the size of the animals
• B. To help in the functioning of reproductive system
• C. To provide space for the development of organs and systems
• D. All of these options are correct

Explanation: Coelom is the fluid-filled body cavity of an animal that contains all the organs. It is more evidently recognized in the beginning stages of development. As we have read on the basis of coelom, animals are divided into three categories, acoelomate(no coelom), pseudocoelomate(false coelom), and coelomate(true coelomate). This is a cavity found in the walls of the mesoderm. It provides space for organs and body parts to grow in. In most animals, it is located between the intestinal canal and the body cavity. Ceolom is the space surrounded by mesoderm. It is used as a sort of cushion for the inner organs. It also allows the body to bend and move around without possibly harming your inner organs and allows your organs to expand. So, option C is correct.

2710. Flame cells in Planaria constitute the:

• A. Digestive system
• B. Reproductive system
• C. Respiratory system
• D. Excretory system

Explanation: Flame cells function like the kidney, removing waste materials throug filteration. The cilia propel waste matter down the tubules and out of the body through excretory pores that open on the body surface; cilia also draw water from the interstitial fluid, allowing for filteration.