Free Biodiversity and Variety of Life MCQs with Answers

2111. Eukaryotes can't share which of the following structures with prokaryotes?

• A. Cell wall
• B. Genetic material
• C. Cytoplasm
• D. Mitochondria

Explanation: OPTION A: The cell wall is present in both prokaryotes and eukaryotes. OPTION B: DNA is the genetic material present in both prokaryotes and eukaryotes. The DNA in prokaryotic cells is contained in the central area of the cell called the nucleoid. Eukaryotic cells have a well-defined nucleus within which the genetic material is present OPTION C: The cytoplasm is an integral part of both prokaryotic and eukaryotic cells. OPTION D: Prokaryotes lack membrane-bounded organelles i.e. Mitochondria, E.R., Golgi bodies, etc while eukaryotes have membrane-bounded organelles. Hence, D is the correct option.

2112. Pilli hollow appendages in bacteria function in?

• A. Motality
• B. Conjugation
• C. Chemical detection
• D. None of above options are correct

Explanation: Option A : Pilli is not involved in motility. Motility is the function of flagella. Option: B Pilli hollow appendages in bacteria function in conjugation. Pilli is primarily involved in the mating process called conjugation. Conjugating bacteria use specialized sex pilli, which are hollow appendages, to transfer genetic material (DNA). Option C : Chemical detection i.e. chemotaxis is the function of flagella.

2113. Prokaryotes that can utilize oxygen if available, but do not require it, are called?

• A. Constitutive anaerobe
• B. Facultative anaerobe
• C. Constitutive aerobe
• D. Obligate anaerobe

Explanation: A facultative anaerobe is any organism that is able to produce energy aerobically and ''switch to anaerobic respiration depending on the amounts of oxygen in the environment.''

2114. The several distinct arrangments of cocci is based on their

• A. Long chain of cells
• B. Planes of division
• C. Grape like clusture shape
• D. All of Above

Explanation: The coccus shape can appear in different arrangements depending upon the plane of division. The coccus can be divided into one, two or three planes. However, random division can also occur. Staphylococci are irregular (grape-like) clusters of cocci (e.g. Staphylococcus aureus). tetrads: Tetrads are clusters of four cocci arranged within the same plane (e.g. Micrococcus sp.). Sarcina: Sarcina is a genus of bacteria that are found in cuboidal arrangements of eight cocci (e.g. Sarcina ventriculi)

2115. The cell wall of a bacterial cell is more permeable in

• A. Gram-positive bacteria
• B. Gram-negative bacteria
• C. Both A and B
• D. Mycoplasmas

Explanation: Since Gram-positive bacteria have a single-layered wall, the movement of particles is easier than that of gram-negative bacteria, which have additional wall layers apart from that of peptididoglycan.

2116. Chemical substances used on living tissues that inhibit the growth of microorganisms are called

• A. Disinfectant
• B. Sanitizer
• C. Antibiotic
• D. Antiseptics

Explanation: Antiseptics prevent the growth of disease-causing microorganisms.

2117. Porphyromonas gingivalis is a gram-negative bacterium found in the oral cavity that is negatively affected by the presence of oxygen. What term best describes this bacteria?

• A. Facultative anaerobe
• B. Aerotolerant anaerobe
• C. Obligate aerobe
• D. Obligate anaerobe

Explanation: Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen.

2118. Which of following is not considered as basic shape of a bacterium?

• A. Cocci
• B. Filamentous
• C. Spiral
• D. Bacilli

Explanation: Option B is correct.On the basis of general shape, bacteria are classified into three categories. These shapes are known as cocci, bacilli and spiral .Although most of the bacterial species have fairly constant characteristic cell shape, yet some cells are pleomorphic and they can exist in a variety of shapes Exceptions to the above shapes are trichome forming, sheathed, stalked,square, starshaped, spindle-shaped, lobed and filamentous bacteria

2119. In a bacterial cell, the plasma membrane with all things present within it is called _.

• A. Cytoplasmic matrix
• B. Cytoplasm
• C. Protoplast
• D. Cell Structure

Explanation: Protoplasm is referred to as the living part of the cell which includes the cytoplasm, nucleus, excluding the cell wall. Thus alone, Option A and B doesn't make sense and option 'C' is the most appropriate option.

2120. Methanopyrus kandleri is an organism which lives in a hydrogen-carbon dioxide environment, and was first discovered in a hydrothermal vent where temperatures reached 230°F. What sort of organism is this?

• A. Protist
• B. Cyanobacteria
• C. Archaea
• D. Bacteria

Explanation: This question requires the candidate to make use of his/her analytical skills, by co-relating the concepts studied in Kingdom Prokaryote. We know that Archae are those organisms which are able to survive in extreme temperature conditions and, the question mentions a high temperature of upto 210 F. Most of the candidates won't know the example mentioned, but they should be able to recognize the concept asked. Thus, Archae is the correct option.