1.
Microbes are:
Correct Answer
C. Living organisms that cannot be seen with naked eyes.
Explanation
Microbes are living organisms that cannot be seen with naked eyes. This is because microbes, such as bacteria, viruses, and fungi, are microscopic in size and can only be observed under a microscope. Despite their small size, microbes play a crucial role in various ecosystems and have significant impacts on human health, agriculture, and the environment.
2.
Microbes can be seen using a microscope.
Correct Answer
A. True
Explanation
Microbes are microscopic organisms that cannot be seen with the naked eye. They are too small to be visible, and therefore, a microscope is required to observe them. This makes the statement "Microbes can be seen using a microscope" true.
3.
Microbiology is:
Correct Answer
A. The science that deals with the study of microbes
Explanation
Microbiology is the science that deals with the study of microbes, which includes bacteria and viruses. This field of study focuses on understanding the structure, function, and behavior of these microorganisms, as well as their impact on human health, the environment, and various industries. By studying microbiology, scientists can develop strategies to control and prevent diseases, improve food safety, and develop new drugs and vaccines.
4.
Microorganisms are present in:
Correct Answer
D. All of the above
Explanation
Microorganisms are present in all of the mentioned options: air, soil, and water bodies. This is because microorganisms are ubiquitous and can be found in various environments. They are present in the air as airborne particles, in the soil as soil bacteria and fungi, and in water bodies as waterborne microorganisms. These microorganisms play important roles in nutrient cycling, decomposition, and maintaining ecological balance in these environments.
5.
Bacteria are found in four different shapes.
Correct Answer
A. True
Explanation
The statement is true because bacteria can be found in four main shapes: cocci (spherical), bacilli (rod-shaped), spirilla (spiral-shaped), and vibrio (comma-shaped). These different shapes allow bacteria to adapt to different environments and perform various functions.
6.
Bacteria that need oxygen for growth are called anaerobic bacteria.
Correct Answer
B. False
Explanation
The given statement is false. Bacteria that require oxygen for growth are called aerobic bacteria, not anaerobic bacteria. Anaerobic bacteria are able to grow in the absence of oxygen.
7.
Bacteria reproduce by binary fission.
Correct Answer
A. True
Explanation
Bacteria reproduce by binary fission, a process in which a single bacterium divides into two identical daughter cells. During binary fission, the bacterium's DNA replicates, and the two copies move to opposite ends of the cell. The cell then elongates and pinches off, resulting in two separate cells. This form of asexual reproduction allows bacteria to rapidly multiply and colonize various environments. Therefore, the statement "Bacteria reproduce by binary fission" is true.
8.
Select the mode of nutrition in Bacteria.
Correct Answer
D. All of the above
Explanation
The mode of nutrition in Bacteria can be autotrophic, saprophytic, or parasitic. Autotrophic bacteria are able to produce their own food through photosynthesis or chemosynthesis. Saprophytic bacteria obtain nutrients by decomposing dead organic matter. Parasitic bacteria rely on living hosts to obtain nutrients. Therefore, all of the above options are correct as they represent different modes of nutrition in bacteria.
9.
Smallest microorganism.
Correct Answer
A. Virus
Explanation
Viruses are considered the smallest microorganisms because they are much smaller than bacteria, algae, and fungi. Viruses are tiny infectious agents that can only replicate inside the cells of other organisms. They are composed of genetic material (DNA or RNA) enclosed in a protein coat. Unlike bacteria, algae, and fungi, viruses lack cellular structure and cannot survive or reproduce on their own. They rely on host cells to replicate and cause infections in humans, animals, plants, and even other microorganisms.
10.
The connecting link between the living and nonliving things.
Correct Answer
A. Virus
Explanation
Viruses are considered the connecting link between living and nonliving things because they possess characteristics of both. They are nonliving as they do not have cells and cannot carry out metabolic activities on their own. However, they are living in the sense that they can reproduce and evolve, albeit only within a host cell. Viruses are dependent on host organisms for their survival and reproduction, making them unique in their ability to bridge the gap between living and nonliving entities.