Biology · 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 monerans is devoid of a cell wall?

  1. Actinomycetes

  2. Cyanobacteria

  3. Mycoplasma

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

Mycoplasma are unique among monerans (bacteria) because they completely lack a cell wall. They are the smallest self-replicating organisms and have only a plasma membrane. This makes them resistant to antibiotics like penicillin that target cell wall synthesis. Actinomycetes, cyanobacteria, and regular bacteria all have cell walls.

Multiple choice

Which of the following is a prokaryotic microbe?

  1. Yeast

  2. Sporozoan

  3. Spirochete

  4. Diatom

  5. Choanoflagellate

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Spirochetes are long and slender bacteria, and placed in domain bacteria (prokaryote). These are thin, corkscrew-shaped, gram-negative and flexible organisms that range in length from a few to as many as 500 µm.

Multiple choice

Characters homologous with conserved function are known as

  1. analogues

  2. orthologues

  3. paralogues

  4. xenologues

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Orthologues are genes in different species that evolved from a common ancestral gene via speciation and normally retain the same function. Analogues share similar functions due to convergent evolution rather than common ancestry, while paralogues arise via duplication.

Multiple choice

Which of the following unicellular organisms has a macronucleus for trophic function and one or more micronuclei for reproduction?

  1. Trypanosoma

  2. Paramecium

  3. Euglena

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

The macronucleus controls non-reproductive cell functions, expressing the genes needed for daily functioning. The micronucleus is the generative or germline nucleus, containing the genetic material that is passed along from one generation to the next.

Multiple choice

In contrast to Annelids the Platyhelminths show

  1. absence of body cavity

  2. presence of pseudocoel

  3. radial symmetry

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

 In contrast to Annelids the Platyhelminths show absence of body cavity. They are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion.

Multiple choice

Barophilic prokaryotes

  1. grow slowly in highly alkaline frozen lakes at high altitudes

  2. grow and multiply in very deep marine sediments

  3. readily grow and divide in sea water enriched in any soluble salt of barium

  4. occur in water containing high concentration of barium hydroxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 Barophilic prokaryotes grow slowly in highly alkaline frozen lakes at high altitudes.They are also known as Piezophiles.

Multiple choice

From the following statements, select the wrong one.

  1. Prawn has two pairs of antennae.

  2. Millepedes have two pairs of appendages in each segment of the body.

  3. Animals belonging to Phylum Porifera are exclusively marine.

  4. Nematocysts are characteristic of the phylum cnidaria.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  Animals belonging to Phylum Porifera are exclusively marine.This statement is wrong one as There is, however, one family of fresh water sponges (Family Spongillidae). 

Multiple choice

Auxospores and hormocysts are formed, respectively, by

  1. some cyanobacteria and many diatoms

  2. several diatoms and a few cyanobacteria

  3. several cyanobacteria and several diatoms

  4. some diatoms and several cyanobacteria
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Auxospores and hormocysts are form, respectively, by several diatoms and a few cyanobacteria. Auxospores typically play a role in growth processes, sexual reproduction or dormancy in some species of diatoms. Hormocysts are the specialised structures found in cyanobacteria which help in reproduction.