Biology ยท Science General

Diversity in Living Organisms

3,323 Questions

The diversity in living organisms deals with the classification of life forms into various kingdoms and phyla. This topic covers specific traits of bacteria, animal body cavities, and structural adaptations for survival. These fundamentals are crucial for biology sections in medical entrance and state board exams.

Animal phyla characteristicsBacteria and flagellaBiological adaptationsKingdom Animalia classificationBody cavity typesExtinct organism subphylaJawless animals identification

Diversity in Living Organisms Questions

Multiple choice

Which of the following statements is false about corals?

  1. Some corals can catch small fish and plankton.

  2. Corals typically live in compact colonies of many non-identical individual polyps.

  3. A coral head is a colony of myriad genetically identical polyps.

  4. Individual heads grow by asexual reproduction of polyps.

  5. An exoskeleton is excreted near the base.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria. They typically live in compact colonies of many identical individual polyps.

Multiple choice

Which of the following sponges is/are the solitary, living sponges characterised by ptychocysts?

  1. Demosponge

  2. Hexactinellids

  3. Octocorallia

  4. Hexacorallia

  5. Cerianthids
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Cerianthids look very similar to sea anemones. They are solitary, living buried in soft sediments. Tube anemones live and can withdraw into tubesthat are made of a fibrous material, which in turn is made from secreted mucus and threads of nematocyst-like organelles known as ptychocysts.

Multiple choice

A hermaphrodite is an organism that has reproductive organs of both male and female sexes. Which of the following sponges is a hermaphrodite sponge?

  1. S. officinalis

  2. Agelas clathrodes

  3. Chalinula nematifera

  4. Azure vase sponge

  5. Haliclona compress
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

S. officinalis is a hermaphrodite having both ova and sperm. When ripe, their sperm escape from the body through vents and float around in the sea until they are sucked into the pores of another sponge by a water current. This sponge is dark grey or purplish when alive. When dry they can either be yellow or brown.

Multiple choice

Which of the following statements regarding the octopus is INCORRECT?

  1. Octopuses are characterised by suction cups.

  2. Reproduction is a cause of death in octopuses.

  3. Octopuses have a long life expectancy.

  4. Octopuses have three hearts.

  5. An octopus has a highly complex nervous system.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Octopuses have a relatively short life expectancy and some species live for as little as six months.

Multiple choice

Which of the following statements regarding the cephalopods is INCORRECT?

  1. Cephalopod vision is acute.

  2. Cephalopods are the only mollusks with a open circulatory system.

  3. Most cephalopods possess chromatophores.

  4. Cephalopods can change their colours.

  5. Most cephalopods can move by jet propulsion.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cephalopods are the only mollusks with a closed circulatory system. Coleoids have two gill hearts (also known as branchial hearts) that move blood through the capillaries of the gills. A single systemic heart then pumps the oxygenated blood through the rest of the body.

Multiple choice

Pinctada is a genus of saltwater clams. Which of the following members of Pinctada is the only known species that produces the South Sea pearls?

  1. P. radiata

  2. P. margaritifera

  3. P. maxima

  4. P. mazatlanica

  5. P. albina
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pinctada maxima is the only species that produces South Sea pearls. Currently south sea pearls are cultured primarily in Australia and Tahiti. Because these pearl oysters are so large, a much larger nucleus than usual can be used in culturing.

Multiple choice

Which of the following is the genus of pen shells?

  1. Mya

  2. Octopus

  3. Vema

  4. Solen

  5. Pinna
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Pinna is a genus of pen shells. It is a cosmopolitan genus of bivalve molluscs characterised by elongated and wedge-shaped shells, which most commonly stand point-first in the sea bottom in which they live, anchored by a net of byssus threads.

Multiple choice

Nematodes are _________.

  1. pseudocoelomate

  2. coelomate

  3. acoleomate

  4. haemocoelomate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nematodes have a pseudocoelom, which is a body cavity not completely lined by mesoderm. This distinguishes them from true coelomates where the cavity is fully lined by mesoderm on both sides.