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

Which among the following statements does not characterise lichens?

  1. Lichens come in many colours.

  2. A lichen is made of a simple photosynthesising organism.

  3. A fungus is called a mycobiont.

  4. The fungal partner protects the alga.

  5. A lichen is a composite organism.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The algal partner protects the fungal partner by retaining water, serving as a larger capture area for mineral nutrients and, in some cases, provides minerals obtained from the substrate.

Multiple choice

The first free-living organism to have its genome completely sequenced was a red alga. Which of the following algae is that?

  1. C. merolae

  2. A. hypnoides

  3. Galaxaura

  4. Gelidiella

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

C. merolae is a club-shaped, unicellular red alga that lives in highly acidic environments and in warm conditions. C. merolae has a single chloroplast and a single mitochondrion, but lacks a vacuole and a cell wall. The organism's genome was the first full algal genome to be sequenced in 2004; its plastid was sequenced in 2000 and 2003, and its mitochondrion in 1998.

Multiple choice

In Asia, rhodophytes are important sources of food, such as nori. Which among the following statements does not characterise the division Rhodophyta?

  1. Red algae are some of the oldest eukaryotic organisms on the planet.

  2. Red algae contain phycobilins.

  3. Red algae do not have flagella at any stage of their life cycle.

  4. Red algae act as habitat and food for some organisms.

  5. Red algae are typically found in fresh running water.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

They are very abundant in tropical and warm waters, although many are found in cooler waters.Red algae are typically found in marine waters attached to rocks or other plants in the calmer, deeper waters beyond the tidal zone.

Multiple choice

A doctor told a couple that their son is suffering from dermatitis, which is a severe skin disease. Which of the following algae is associated with dermatitis?

  1. Anabaena

  2. Cylindrospermopsis

  3. Nodularia

  4. Microcystis aeruginosa

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

Oscillatoria is blue greenish in colour, usually free floating or entwined with other algae. It is widespread. There are approximately 150 known species of which 47 are known to occur in Australia. Some species causes contact irritation leading to severe dermatitis.

Multiple choice

Which among the following statements regarding the characteristics of dinoflagellates is incorrect?

  1. Many are thecate, having an internal skeleton of cellulose-like plates.

  2. Their chromosomes are always condensed.

  3. They are small.

  4. Dinoflagellates usually reproduce sexually.

  5. They are planktonic.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The most form of reproduction is asexual, where daughter cells form by simple mitosis and division of the cell. The daughter cells will be genetically identical to that of the original cell. The thecal plates may either be divided, or completely shed and then reformed.

Multiple choice

Blue-green algae are able to produce highly potent toxins. Which among the following toxins is/are not produced by blue-green algae?

  1. Endotoxins

  2. Non-specific toxins

  3. Hepatotoxins

  4. Gyromitrin

  5. Neurotoxins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gyromitrin is a toxin and carcinogen present in several members of the fungal genus Gyromitra, most notably the false morel G. esculenta. It is unstable and is easily hydrolyzed to the toxic compound monomethylhydrazine, a component of some rocket fuels.

Multiple choice

Which among the following statements regarding blue-green algae is false?

  1. The DNA in blue-green algae is contained within a single, circular, looping chromosome.

  2. Blue-green algae have the ability to produce toxins.

  3. Most blue-green algae may appear red, yellow, green, brown or black.

  4. Blue-green algae do not exhibit sexual reproduction.

  5. Homocystous cells can perform nitrogen fixation.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Heterocystous cells can perform nitrogen fixation by absorbing free nitrogen in the air and transform free nitrogen to organic substances that may be used to fertilize the soil. The number and position of heterocysts are important features used to classify blue-green algae.

Multiple choice

Which among the following statements regarding green algae is incorrect?

  1. Green algae have chloroplasts that contain chlorophyll a and chlorophyll b.

  2. All green algae have mitochondria with curved cristae.

  3. Green algae have served as model experimental organisms to understand the mechanisms of osmoregulation.

  4. Green algae contain sulfated polysaccharides.

  5. Green algae are eukaryotic organisms.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

All green algae have mitochondria with flat cristae. When present, paired flagella are used to move the cell. They are anchored by a cross-shaped system of microtubules and fibrous strands.

Multiple choice

In which organism neoblasts are found?

  1. Coelenterates

  2. Planarians

  3. Tunicates

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

Neoblasts are found in Planarians. They are undifferentiated reserve cells and help in regeneration

Multiple choice

Which among the following statements regarding the vestigial organs is incorrect?

  1. Vestigial traits can still be considered adaptations.

  2. Vestigial structures are often heterologous to structures that are functioning normally in other species.

  3. There are also vestigial molecular structures present in humans.

  4. The formation of goose bumps in humans under stress is a vestigial reflex.

  5. The human caecum is a vestigial organ.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.

Multiple choice

Which two adaptations in a polar bear helps it to catch prey for food?

  1. Fatty, skin and thick fur

  2. Strong sense of smell and white fur

  3. White fur and fatty skin

  4. Thick and white fur
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Polar bears have a strong sense of smell and their bodies are covered with white fur. These features help them to locate and catch their prey easily without letting it escape.