CLASS ELEVEN BIOLOGY CHAPTER 2 BIOLOGICAL CLASSIFICATION QUESTIONNAIRE PART 6

  CLASS ELEVEN BIOLOGY CHAPTER 2 BIOLOGICAL CLASSIFICATION QUESTIONNAIRE FOR TESTS AND REVISION.

PART 6

It can be used as reference material for competitive exams also.

1.     Which kingdom is characterized by heterotrophic eukaryotic organisms with multicellular cells lacking cell walls?

a. This kingdom is Animalia.

2.     How do animals obtain their food, and what is their mode of nutrition?

a. Animals obtain their food through ingestion, and their mode of nutrition is holozoic, meaning they ingest solid food and digest it internally.

3.     How do animals store their food reserves?

a. Animals store food reserves as glycogen or fat, which serve as energy reserves for metabolic activities.

4.     Describe the growth pattern of animals.

a. Animals follow a definite growth pattern from juvenile stages to adults, where they attain a specific shape and size characteristic of their species.

5.     What distinguishes higher forms of animals in terms of sensory and neuromotor mechanisms?

a. Higher forms of animals possess elaborate sensory systems (e.g., eyes, ears) and neuromotor mechanisms (e.g., nervous system) that enable them to respond to stimuli and move effectively in their environments.

6.     How do animals typically reproduce sexually?

a. Sexual reproduction in animals involves copulation between male and female individuals, followed by embryological development of the fertilized egg (zygote) into a new offspring.

7.     What are some examples of phyla within the kingdom Animalia?

a. Examples of animal phyla include Chordata (vertebrates such as mammals and birds), Arthropoda (insects and crustaceans), Mollusca (snails and squids), and Annelida (earthworms and leeches).

8.     How do animals exhibit locomotion?

a. Most animals are capable of locomotion, using mechanisms such as muscles and appendages (legs, wings, fins) to move within their environments.

9.     How does the absence of cell walls in animal cells affect their structure and function?

a. The absence of cell walls allows animal cells to be more flexible and dynamic in shape, enabling them to perform specialized functions such as movement and sensory reception.

10.  Discuss the significance of embryological development in animals.

a. Embryological development in animals involves the formation and differentiation of tissues and organs from a single fertilized egg cell (zygote), leading to the formation of a complex, multicellular organism.

11.  How do animals contribute to ecosystem dynamics?

a. Animals play key roles in ecosystems as consumers, prey, predators, and ecosystem engineers, influencing food webs, nutrient cycling, and habitat structure.

12.  Compare the nutritional strategies of animals with those of plants.

a.  Animals are heterotrophic and ingest food for nutrition, while plants are autotrophic, producing their own food through photosynthesis. Animals rely directly or indirectly on plant-derived organic matter for energy.

13.  Explain the concept of copulation in animal reproduction.

a.  Copulation refers to the physical mating process between male and female animals, involving the transfer of sperm from male to female reproductive systems for fertilization.

14.  How do animal sensory systems contribute to their survival?

a.  Animal sensory systems, including sight, hearing, touch, taste, and smell, allow them to detect and respond to environmental stimuli, locate food, avoid predators, and communicate with conspecifics.

15.  What are some adaptations in animals for locomotion in different environments?

a. Animals have evolved various adaptations for locomotion, such as wings for flight in birds and insects, fins for swimming in fish, legs for walking in mammals and reptiles, and specialized appendages for crawling in arthropods.

16.  What classification system did Whittaker propose, and what organisms were not included?

a. Whittaker proposed the five kingdom classification system, which did not include viruses, viroids, prions, or lichens.

17.  Why are viruses considered non-living entities?

a. Viruses lack cellular structure and cannot carry out metabolic processes independently. They rely on host cells to replicate.

18.  Who discovered viruses, and what was their initial classification?

a. Dmitri Ivanowsky in 1892 first recognized viruses as agents causing mosaic disease in tobacco plants. They were initially classified as non-cellular infectious particles.

19.  What did M.W. Beijerinek contribute to the understanding of viruses?

a. Beijerinek demonstrated in 1898 that extracts from infected tobacco plants could transmit the disease to healthy plants, naming the infectious agent "virus."

20.  What is the structure of a virus outside of a host cell?

a. Outside of a host cell, viruses exist as inert crystalline structures, primarily composed of proteins.

21.  How do viruses replicate within host cells?

a. Viruses infect host cells and take over their cellular machinery to replicate their genetic material and assemble new virus particles, often leading to the death of the host cell.

22.  Describe the composition of a virus.

a. Viruses consist of a protein coat called a capsid, which protects their genetic material. The genetic material can be either RNA or DNA, but not both simultaneously.

23.  What is unique about the genetic material of viruses?

a. Viruses carry either RNA or DNA as their genetic material, which is infectious and can cause diseases in host organisms.

24.  How do viruses cause diseases in plants and animals?

a. In plants, viruses can cause symptoms like mosaic formation, leaf rolling, yellowing, and stunted growth. In animals, viruses can cause diseases such as mumps, smallpox, herpes, influenza, and AIDS.

25.  What are bacteriophages, and what type of genetic material do they typically contain?

a.  Bacteriophages are viruses that infect bacteria, often containing double-stranded DNA as their genetic material.

26.  How do viruses contribute to the study of genetics and molecular biology?

a. Viruses are valuable tools in genetic research for studying gene function, regulation, and expression. They also serve as vectors for gene transfer in biotechnology.

27.  Who demonstrated that viruses could be crystallized, and what did this discovery reveal?

a.  W.M. Stanley in 1935 demonstrated that viruses could be crystallized, revealing their proteinaceous nature and reinforcing their classification as non-living infectious agents.

28.  What distinguishes viroids from viruses?

a. Viroids are smaller infectious agents composed solely of single-stranded RNA and lack the protein coat (capsid) found in viruses.

29.  How were viroids discovered, and what disease do they cause in plants?

a.  Viroids were discovered in 1971 by T.O. Diener and cause diseases like potato spindle tuber disease in plants.

30.  What are prions, and what diseases are associated with them?

a. Prions are infectious agents composed of abnormally folded proteins. Diseases associated with prions include bovine spongiform encephalopathy (BSE or mad cow disease) and Creutzfeldt-Jakob disease (CJD) in humans.