Biology · Science General

Diversity in Living Organisms

3,829 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

The breakdown of enzyme resistant cellulose in sheep, is done by

  1. aerobic bacteria

  2. protozoa

  3. Both (1) and (2)

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Protozoa in the rumen produce cellulase enzymes that break down enzyme-resistant cellulose in sheep. While bacteria also contribute to fermentation, protozoa are particularly important for cellulose digestion. This is an anaerobic process, not requiring aerobic bacteria which cannot survive in the rumen environment.

Multiple choice

Dolphins have

  1. homodont and indefinite teeth

  2. hetrodont and definite teeth

  3. homodont and definite teeth

  4. hetrodont and indefinite teeth
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Dolphins have homodont dentition (all teeth are similar in shape, conical for catching fish) and polyphyodont/indeterminate replacement (continuous tooth replacement throughout life). 'Heterodont' refers to having different tooth types like incisors, canines, and molars, which dolphins do not have. 'Definite' teeth would mean a fixed number, which is not true for dolphins.

Multiple choice

Flatworms are _________ animals with organ level of organisation.

  1. radially symmetrical, diploblastic and coelomate

  2. radially symmetrical, diploblastic and acoelomate

  3. radially symmetrical, triploblastic and acoelomate

  4. bilaterally symmetrical, diploblastic and coelomate

  5. bilaterally symmetrical, triploblastic and acoelomate
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Correct answer. Flatworms are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation.

Multiple choice

Which of the following statements are false regarding bacteria?

P. The cytoplasm of a bacterium is supported by microtubules. Q. Bacterial glycocalyx is located inside the cell wall. R. A gram-positive bacterium is stained purple by the gram stain. S. Fimbriae help bacteria to get attached to the other structures.

  1. P and Q

  2. P and R

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct answer. Both are false statements. The cytoplasm of a bacterium has no internal support structure. Bacterial glycocalyx is a sticky, gelatinous polymer that is external to the cell wall and is composed of polysaccharide, polypeptide or both.

Multiple choice

The most important characteristic of a living organism is

  1. locomotion

  2. reproduction

  3. growth

  4. cell wall
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 The most important characteristic of a living organism is reproduction. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction.

Multiple choice

Organs of different organisms having similar function but different in origin are

  1. homologous organs

  2. analogous organs

  3. vestigial organs

  4. all of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Analogous organs are structures in different organisms that perform similar functions but have different evolutionary origins and anatomical structures. Examples include wings of bats (skin membrane) versus birds (feathers), or eyes of octopuses versus mammals. These arise through convergent evolution - similar environmental pressures lead to similar functional solutions.

Multiple choice

Forelimb of horse, human, whale and bat are

  1. connecting links

  2. analogous organs

  3. homologous organs

  4. vestigial organs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Homologous organs have similar anatomical structure but different functions, indicating common ancestry. Horse forelimbs (running), human hands (manipulation), whale flippers (swimming), and bat wings (flying) all share the same basic bone structure. Analogous organs have different origins but similar functions, while vestigial organs are reduced and non-functional.

Multiple choice

Animals which remain fixed at one place have

  1. radial symmetry

  2. bilateral symmetry

  3. Both (A) and (B)

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Radial symmetry is characteristic of many sedentary (fixed) animals, e.g., coelenterate and Echinodermata.

Multiple choice

Snakes mainly respond to

  1. earth-borne sound vibrations through the quadrate bone

  2. air-borne sound vibrations through the quadrate bone

  3. earth-borne sound vibrations through squamosal bone

  4. Both (A) and (B)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Snakes mainly respond to earth-borne sound vibrations through the quadrate, although they are also sensitive to low frequency air-borne sound vibrations.

Multiple choice

Which of the following is not the basic feature that groups all organisms into a hierarchical classification?

  1. Nature of the cell, i.e. consisting of a clearly demarcated nucleus or not

  2. Unicellular or multi-cellular organism showing division of labour

  3. Habitat of the organism

  4. Whether the organism (plant) is an autotroph or not

  5. Whether the animal has specialised organs for different functions
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is not a basic feature that is considered while classifying all organisms into a hierarchical classification. Many organisms may not have any similarities except common habitat. Thus, this is the correct answer choice.