Test: The Living World - Assertion and Reasoning - NEET MCQ

Taxonimic studies of various species of plants and animals are useful in agriculture, forestry, industry and in general in knowing our bio-resources and their diversity.  Taxonomic studies would require correct classification and identification of organisms.

It is nearly impossible to study all the living organisms. Classification refers to the process by which individuals are grouped into categories. So, classification makes it possible to study all the living organisms by studying the category wise characteristic.

Taxonomy is the science of identification, nomenclature and classification of organisms. But taxonomy and systematics are different terms. Systematics is the branch of biology that deals with diversity of organisms at every level of classification.

All the members of a species have similar karyotype (cytotaxonomy) - there is similarity in the number, size, shape and behaviour of chromosomes. At the molecular level, there is similarity in the types of proteins, enzymes, hormones and other biochemicals.

To evaluate the given Assertion and Reason, let's analyze them one by one:

1. Assertion: "The scientific terms for the categories like dogs, cats, mammals, plants, animals, etc., is taxa."

   • This is true. In biological classification, "taxa" (plural of "taxon") refers to the categories used to classify organisms, which include various levels such as species, genus, family, order, class, phylum, kingdom, etc.

2. Reason: "The taxa can indicate categories at very different levels."

   • This is also true. Taxa can represent a range of classifications from specific (like species) to broad (like kingdom), indicating different hierarchical levels of biological classification.

Now, let's consider the options:

• a) If both Assertion and Reason are false.

  • This is incorrect, as both statements are true.

• b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

  • This is incorrect because the Reason provides a valid explanation of the Assertion.

• c) If Assertion is true but Reason is false.

  • This is incorrect since both are true.

• d) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

  • This is correct because both the Assertion and Reason are true, and the Reason correctly explains why the Assertion is true.

The correct answer is d) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

The assertion that both internal and external growth is shown by living organisms is incorrect. In living organisms, growth is primarily internal, occurring through cell division and enlargement within the organism, a process known as intussusception. External growth, or accretion, typically refers to non-living entities where growth happens by adding materials to the surface. Therefore, both the assertion and reason are false

All living organisms are made of chemicals. These chemicals, small and big, belonging to various classes, sizes, functions, etc., are constantly being made and changed into some other biomolecules. These conversions are chemical reactions or metabolic reactions. There are thousands of metabolic reactions occurring simultaneously inside all living organisms, be they unicellular or multicellular.

Living beings are objects exhibiting growth, development, responsiveness and other characteristics of life. They have their own specific form and structure. Living organisms exhibit properties such as metabolism, growth, reproduction, consciousness, etc. Thus, living organisms are considered as self replicating, evolving and self regulatory interactive systems capable of responding to external stimuli, sharing a common genetic material to varying degree both horizontally and vertically.

• Assertion: "All organisms reproduce for the perpetuation of a population." This is true because reproduction in most organisms serves the function of perpetuating the population, even if the method of reproduction can vary.

• Reason: "Reproduction is an all-inclusive characteristic of living organisms." This is false, because as the reference points out, there are exceptions — not all living organisms reproduce. For example, sterile organisms like mules or certain worker bees cannot reproduce, which disqualifies reproduction as an "all-inclusive" characteristic of life.

Hence, the correct option is d.

Both living and non-living entities resemble each other at the lower level of organization.

Growth is the act or process, or a manner of growing; development; gradual increase.
It is an exclusive event in majority of the higher animals and plants. In plants, growth occurs continuously throughout their life span and in animal, growth is seen only up to a certain age. In living organisms, growth is from inside. Therefore, it cannot be taken as a defining property of living organisms.

Accu mulation of material by external agency cause extrinsic growth which can not be the feature of living organism.

All organisms, from primitive prokaryotes to most advanced and complex eukaryotes, are able to sense and respond to environmental factors. The stimuli are perceived by sense organs in higher animals through sensory receptors e.g. eyes, ears, nose. Plants do not possess such sense organs. However, they do respond to external factors such as light, water, temperature, pollutants, other organism, etc. Human beings have an additional facility of self conciousness (awareness of self). Consciousness and response to stimuli are said to be the defining properties of living organisms.

The correct answer is:

4.  If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation:
- The assertion states that reproduction cannot be referred to as a defining property of living organisms, which is true.
- The reason given is that there are some living organisms that do not reproduce, such as mules, worker bees, and infertile humans, which is also true.
- The reason correctly explains why reproduction is not a defining property of living organisms since not all living organisms are capable of reproduction.

All organisms from primitive prokaryotes to most advanced and complex eukryotes are able to sense and respond to environmental factors. The stimuli are perceived by sense organs in higher animals through sensory receptors.
Consciousness and response to stimuli are said to be the defining properties of living organism.

In fungi, vegetative reproduction occurs by fragmentation, budding (yeast), sclerotia, rhizomorphs, etc. Asexual reproduction occurs through formation of asexual spores such as zoospores, sporangiospores, chlamydospores, oidia, coidia, etc.

In Whittaker's classification, algae are grouped in three kingdoms - Monera (bluegreen algae), Protista (dinoflagellates, diatoms, euglenoids) and Plantae (red algae, brown algae and green algae). Though plant kingdom of Whittaker is often called metaphyta or multicellular plants, the algae included in this kingdom also contain a number of unicellular and colonial forms. The most accepted classification of algae is given by Fritsch. He classified all algae into 11 classes.

Systematics is related with classification, of organisms. In classification, the organisms are grouped on the basis of their characters or phylogeny, etc.

Anyone can study, describe, identify and give a name to an organism provided certain rules are followed. These rules are formed and standardised by International Code of Botanical Nomenclature (ICBN). It uses articles, photographs and recommendations.