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 botany the living world archaebacteria the three domains of life classification of microbes

This taxonomic group of living organisms includes the extreme halophiles, methanogens, and extreme thermophiles. This group has also been extant for about 3.7 billion years, and their cell lacks a nucleus and membrane bound organelles. Which of the following groups of life is being described here?
I. Domain Eukarya
II. Domain Archaea
III. Domain Bacteria        

  1. I only

  2. II only

  3. III only

  4. I and II

  5. II and III
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The archaebacteria are the single-celled, prokaryotic organisms. They do not have well-developed organelles and cellular structures. These organisms can survive in extreme conditions like high temperatures, high salt concentration, high temperature, etc. Some organisms from this group can produce methane through the process of methanogenesis. 

Thus, the correct answer is option B. 

Multiple choice botany the living world archaebacteria the three domains of life classification of microbes
What of the following characteristic is true for archaebacteria?
$(1)$ Extreme halophiles
$(2)$ Extreme thermophiles
$(3)$ Methanogens
$(4)$ Occurrence of peptidoglycan in the cell wall

  1. 1, 2 and 3 are correct

  2. 1 and 2 are correct

  3. 2 and 4 are correct

  4. 1 and 3 are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Peptidoglycan is a polymer that is present in the cell wall of most bacteria. It is also called as Murein. However, Archaebacteria are devoid of peptidoglycan in its wall. Instead, they are made up of the polysaccharide called pseudomurein. Arachebacteria consists of 3 groups, namely halophiles, thermophiles and methanogens. 

Thus, the correct answer is '1, 2 and 3 are correct.'

Multiple choice botany the living world archaebacteria the three domains of life classification of microbes

From the following statements, identify the ones, which are not relevant to archaebacteria.
(a) They live in some of the harshest habitats.
(b) They are present in the gut of several ruminant animals.
(c) They are characterized by the presence of a rigid cell wall.
(d) They include mycoplasma.
(e) They are also referred to as blue-green algae.

  1. (a), (b) and (c)

  2. (a), (c) and (e)

  3. (c), (d) and (e)

  4. (a), (c) and (d)

  5. (b), (c) and (e)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Archaebacteria are a type of single-cell organism which do not have membrane-bound organelles. They also lack true nucleus. They live in some of the harshest habitats. They have cell wall which is made up of polysaccharides and proteins without peptidoglycan. They include Methanogens, halophiles, thermophiles. Methanogens produce methane gas or biogas. They are present in the gut of several ruminant animals. Halophiles are present in areas with high salt concentrations. Thermophiles are present in areas with extremely high temperature.

Thus, the correct answer is '(c), (d) and (e).'

Multiple choice botany the living world archaebacteria the three domains of life classification of microbes

Thermococcus, Methanococcus and Methanobacterium are

  1. Archaebacteria having eukaryotic histone homologue

  2. Bacteria with cytoskeleton

  3. Archaebacteria with negatively supercoiled DNA as in eukaryotes but lacking histones.

  4. Bacteria with positively coiled DNA, cytoskeleton and mitochondria.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Thermococcus, Methanococcus and Methanobacterium are Archaebacteria. They lack histones. They have negatively supercoiled DNA. They differ from bacteria in a way that they survive extreme conditions. Unlike bacteria, archaea cell walls do not contain peptidoglycan. 

Thus, the correct answer is option C.

Multiple choice botany the living world archaebacteria the three domains of life classification of microbes

Choose the correct answers from the alternatives given.
Which of the following domains contains the most primitive bacteria that live in extreme environments?

  1. Archaea

  2. Plantae

  3. Fungi

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

Archaebacteria differ from other bacteria in having a different cell wall structure and this feature is responsible for their survival in extreme conditions.

Hence, the correct answer is 'Archaea'.

Multiple choice botany the living world archaebacteria the three domains of life classification of microbes

Methanogens belong to

  1. Slime moulds

  2. Eubacteria

  3. Archaebacteria

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

Methanogens belong to archaebacteria. They are strict anaerobes. They are autotrophs which obtain both energy and carbon from decomposition products. They occur in marshy areas where they convert formic acid and carbon dioxide into methane with the help of hydrogen. This capability is commercially exploited in the production of methane and fuel gas inside gobar gas plants, e.g., Methanobacterium, Methanococcus. Some of the methanogens live as symbionts inside rumen of herbivorous animals that chew their cud. These archaebacteria are helpful to the ruminants in fermentation of celullose.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Cyanobacteria are photosynthetic prokaryotes. Which of the following cell structures are absent in cyanobacteria?

I. Cell membrane
II. Nucleus
III. Ribosomes

  1. I only

  2. II only

  3. III only

  4. I and II only

  5. I and III only
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cyanobacteria are prokaryotes so, they lack a membrane-bound well-defined nucleus. Cell membrane and ribosomes are the cell structures, common to both prokaryotes and eukaryotes.

Therefore, the correct answer is option B.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The nuclear material without nuclear membrane is observed in

  1. Bacteria and green algae

  2. Cyanobacteria and red algae

  3. Bacteria and cyanobacteria

  4. Mycoplasma and green algae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacteria and cyanobacteria are prokaryotes, i.e., having pro or primitive karyon. These cells have primitive nucleus, not having a distinct nuclear membrane. These cells have a single circular molecule of DNA as genetic material but it is not present inside membrane bound nucleus.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Coenocytic condition is found in ______________.

  1. Ulothrix

  2. Chlamydomonas

  3. Spirogyra

  4. Vaucheria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Vaucheria is commonly known as “water felt”; the sparsely branched or unbranched coenocytic filaments often form feltlike mats. The often macroscopic cells contain a large number of discoid plastids, with or without pyrenoids. Reproduction occurs by zoospores, aplanospores, and akinetes.

Hence D is the correct option. 

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Well defined nucleus is absent in

  1. Blue green algae

  2. Diatoms

  3. Algae

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

Algae are a very large and diverse group of eukaryotic organisms, ranging from the microscopic unicellular Chlorella and the diatoms to giant multicellular kelps, the large brown alga. Diatoms are algae (most commonly known as phytoplanktons) with secondary chloroplasts derived from an endosymbiotic red alga. Yeats is also a eukaryote belonging to the kingdom Fungi. However, the Blue-green algae or Cyanobacteria is the most primitive photosynthetic bacteria (prokaryotic- the absence of well-defined nucleus) cell which is quite small and usually unicellular, though they often grow in colonies large enough to see.
Hence, the correct answer is option A.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Acetabularia used in Hammerling's nucleocytoplasmic experiments is

  1. Unicellular fungus

  2. Multicellular fungus

  3. Unicellular uninucleate green alga

  4. Unicellular multinucleate green alga
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Acetabularia is a genus unicellular or single-celled green algae belonging to the family Polyphysaceae which are found in subtropical waters.

  • They are gigantic in size and complex in form, therefore, used in experiments in cell biology.
  • Hammerling's nucleocytoplasmic experiments state that the cytoplasm is the centre for all the metabolic activities in the cell and the nucleus is the controlling centre. 
  • So, the correct answer is 'Unicellular uninucleate green alga'.