Free Biodiversity and Variety of Life MCQs with Answers

2121. All of the following are characteristics of prokaryotic cell except for?

• A. Unicelularity
• B. Lack of membrane bound organelles
• C. A cell wall
• D. Examples are protists and fungi

Explanation: Option D is correct since fungi and protists are classified as eukaryotes. Prokaryotes and Eukaryotes are two different domains. Therefore, prokaryotic cells make up prokaryotes while eukaryotic cells make up eukaryotes. Option A is incorrect as unicellularity is a feature of prokaryotic cells. All prokaryotic cells are unicellular whereas eukaryotic cells may be unicellular or multicellular. Option B is incorrect since prokaryotic cells do not have membrane-bound organelles. Option C is incorrect since prokaryotic cells possess a peptidoglycan cell wall.

2122. The Prokaryotic Life is characterized by:

• A. Absence of locomotion
• B. Absence of nuclear envelope
• C. Absence of Protein
• D. Absence of nuclear material

Explanation: Prokaryotic life is characterized by the absence of a nucleus and membrane-bound organelles in the cells. Prokaryotic cells are typically smaller and simpler in structure than eukaryotic cells, and they contain a single, circular chromosome that is not enclosed in a nuclear membrane. Prokaryotic cells also lack other membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Instead, they have a cell wall, plasma membrane, and cytoplasm that contains ribosomes, which are responsible for protein synthesis. Prokaryotic cells can be divided into two main groups: bacteria and archaea. They are found in a wide range of environments, including soil, water, air, and the bodies of plants and animals. Prokaryotes play important roles in many ecological processes, such as nutrient cycling, decomposition, and symbiotic relationships with other organisms. They are also used in many biotechnological applications, such as genetic engineering, bioremediation, and food production.

2123. The existance of microbes was confirmed by:

• A. Robert Kuch's work
• B. Louis Pasteur's work
• C. Linneaus's work
• D. Ernst Hackel's work

Explanation: Louis Pasteur was the scientist who is credited with definitively proving the existence of microbes. In the mid-19th century, Pasteur conducted a series of experiments that demonstrated the role of microorganisms in fermentation, putrefaction, and disease. His work laid the foundation for the field of microbiology and led to the development of many important medical and industrial applications, such as vaccines and pasteurization.

2124. In bacterial categories the bacteria smaller in number are which of the following?

• A. Gram-negative bacteria
• B. Gram-positive bacteria
• C. Eubacteria
• D. Ancient bacteria

Explanation: Most of the ancient bacteria must have evolved to form modern bacteria or must have gone extinct, that is the reason for their small number.

2125. Compared to gram negative bacteria, how many more membrane-bound organelles do gram positive bacteria contain?

• A. 0
• B. 1
• C. 3
• D. 2

Explanation: Gram negative and gram positive bacteria contain the same number of membrane bound organelles.

2126. Which of the following structure provides greater pathogenicity to the bacteria?

• A. Slime
• B. Cell wall
• C. Cell membrane
• D. Capsule

Explanation: Correct option: A slime is an extracellular layer that surrounds a bacterial cell and is composed of exopolysaccharide,glycoprotein and glycolipid and is responsible for the pathogenicity of bacteria.

2127. A much smaller and ancient bacteria are present in group

• A. Archaebacteria
• B. Lactobacteria
• C. Eubacteria
• D. Anaerobic bacteria

Explanation: Archaebacteria are a distinct group of microorganisms that can survive in extreme environments and are among the oldest forms of life on Earth. "Lactobacteria" is not a recognized term, but "Lactobacillus" is a genus of beneficial bacteria used in fermentation and probiotics. Eubacteria are true bacteria, encompassing a wide range of microorganisms with both positive and negative effects on human health. Anaerobic bacteria are able to survive without oxygen and can be beneficial or harmful depending on the specific species.

2128. All of the following is true about bacilli bacteria except?

• A. All bacilli are gram-positive
• B. All bacilli are aerobic
• C. All bacilli are rod-shaped
• D. Both A and B

Explanation: Option D is correct because the question mentions to mention the incorrect options and both options A and B are incorrect about bacilli.

2129. When a water sample from a hot thermal vent was tested, it was found to contain a single-celled organism having a cell wall lacking a nucleus. What is its classification most likely?

• A. Eukarya
• B. Fungi
• C. Protista
• D. Archaea

Explanation: The most likely classification for a single-celled organism with a cell wall lacking a nucleus is Archaea. Archaea are a type of prokaryote, which means they are single-celled organisms that lack a nucleus and other membrane-bound organelles. They are found in extreme environments, such as hot thermal vents, and are thought to be the ancestors of all other life on Earth.

2130. Coagulation of bacteria means:

• A. Functional
• B. Conjugation
• C. Normal
• D. Non-functional

Explanation: Coagulation refers to the formation of a solid clot. When bacteria are heated, the bacterial proteins coagulate and become non-functional.Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. This takes place through a pilus.