Practice Test - NEET MCQ

To describe motion along a straight line, we can choose an axis, say X-axis, so that it coincides with the path of the object. We then measure the position of the object with reference to a conveniently chosen origin, say O, Positions to the right of O are taken as positive and to the left of O, as negative.

Explanation:Position-time graph of horizontal straight line parallel to time axis represents that the position of the body does not changes with the passage of time. So it represents the rest state of motion.It means velocity of object is zero.

Explanation:To describe motion along a straight line, we can choose an axis, say X-axis, so that it coincides with the path of the object. We then measure the position of the object with reference to a conveniently chosen origin, say O,  Positions to the right of O are taken as positive and to the left of O, as negative.

Explanation:

Acceleration is the rate of change of velocity with time.It is a vector quantity.

Average acceleration is the change in velocity per unit time over an interval of time.

Let initial velocity at time interval t​​​​​​₁ is v​​​​​​₁ and final velocity at time interval t​​​​​₂ is v​​​​​​₂ Then

The law of definite proportions, also known as the law of constant composition states that all pure samples of the same chemical compound contain the same elements combined in the same proportions by mass.
What this law emphasizes is that, if pure samples of the same chemical substance, wherever they may be found, are analyzed, it will be found that they all consist of the same elements, as well as having these elements combine in the same proportions by mass.
For examples, pure sample of copper(II) oxide is composed of copper and oxygen, in the proportion of 1:1 by mole, or 64 g of copper to 16 g of oxygen or 1 g of copper to 0.25 g of oxygen. 

Chemical reactions involve merely the combination, separation, or rearrangement of atoms and that during these processes atoms are not subdivided, created, or destroyed.

According to Gay Lussac's Law of Gaseous Volume, under same pressure and temperature, whenever gases react, they do so in volumes and volumes of reacting gases bear a simple ratio with each other and with product gases formed. 100 : 50 : 100 : : 2 : 1: 2 Hence, option B is correct.

The element with atomic number(Z) 17 & mass number (A) 35 is chlorine = 

Only in CH₃CH₂OH, carbon has sp³ hybridisation. In other molecules, the carbon atom has multiple bonds.

The bond order of given molecules are:
NO = 2.5, NO⁺ = 3, O₂ = 2, NO^– = 2
Larger the bond order, the smaller the bond length.
NO⁺ has the largest bond order 3.
Therefore, it will have the smallest bond length.
Hence option A is the answer.

• The category "Genus" comprises a group of related species with more common characteristics than species of other genera.
• It is one level above species in the hierarchy.

• All organisms share common genetic material, i.e., DNA and RNA. However, it can vary to certain degrees.
• In fact, the whole theory of evolution is based on the similarity of genetic materials which indicates common ancestry for living organisms. Variations in the similarity of genetic material give biodiversity which we see all around us.

Hence, the Correct Answer is B

NCERT Reference: Chapter- "The Living World"  of NCERT

The correct option is A Decrease
In the Linnaean system of hierarchy, as we go from species to kingdom, the number of common characters decreases, while in the descending order, the number of common characteristics increases. For example, any genus (lower grade of classification) has members with more similarities as compared to a family (a higher grade of classification) which has members with fewer similarities among them.

• Carl Linnaeus was a Swedish botanist, physician and zoologist, who laid the foundations for the modern biological naming scheme of biological nomenclature.
• He is known as the father of taxonomy and is also considered one of the fathers of modern ecology.
• In botany, the author abbreviation used to indicate Linnaeus as the authority for the species name. In older publications, sometimes the abbreviation "Linn" is found. Hence, L signifies the taxonomist, Linneaus.

Hence, the Correct Answer is C

• As we go higher from species to kingdom, the number of common characteristics goes on decreasing.
• Lower the taxa, more are the characteristics that the members within the taxon share.
• Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level.

Hence, the Correct Answer is C

• Unlike organisms in the other five kingdoms which are living, viruses are non-living organisms.
• They don’t even have basic unit of life i.e. cell.
• Hence, they are not categorised in any of the kingdoms.

Hence, the correct answer is B
NCERT Reference: Topic “Viroids” of chapter "Biological Classification" of NCERT.

• Mushrooms are the commonly known form of Basidiomycetes, called bracket fungi or puffballs.
• They grow in soil, on logs and tree stumps and in living plant bodies as parasites, e.g., rusts and smuts.

Hence, the correct option is B
NCERT Reference: Topic Basidiomycetes” of chapter "Biological Classification" of NCERT.

Five kingdom classification was proposed by R.H. Whittaker in 1969.
The kingdoms identified by him were:

• Monera
• Protista
• Fungi
• Plantae  
• Animalia

Hence, the correct option is D
NCERT Reference: Topic- Five kingdom classification  of chapter "Biological Classification" of NCERT.

Heterotrophic bacteria are most abundant in nature. The majority are important decomposers.

Commonly known as sac-fungi, the ascomycetes are mostly multicellular, e.g., Penicillium, or rarely unicellular, e.g., yeast (Saccharomyces). They are saprophytic, decomposers, parasitic, or coprophilous (growing on dung).

Some members of deuteromycetes are saprophytes or parasites while a large number of them are decomposers of litter and help in mineral cycling. Some examples are Alternaria, Colletotrichum, and Trichoderma.

1. Pinus - Dioecious: Pinus species are actually monoecious, meaning that both male and female cones are present on the same tree. Therefore, this statement is a mismatch.

2. Cycas - Dioecious: Cycas, a type of cycads, is indeed dioecious, meaning male and female reproductive structures are on separate individuals. This statement is correct.

3. Salvinia - Heterosporous: Salvinia, a genus of aquatic ferns, is indeed heterosporous, meaning it produces two types of spores: microspores and megaspores. This statement is correct.

4. Equisetum - Homosporous: Equisetum, commonly known as horsetails, is indeed homosporous, producing only one type of spore that develops into a bisexual gametophyte. This statement is correct.

Thus, the mismatch is:

(1) Pinus - Dioecious

In Bryophytes, the sporophyte does not have a free-living stage. It is dependent on the gametophyte for nutrition and support. This contrasts with other plant groups like Pteridophytes and Gymnosperms, where the sporophyte is the dominant, free-living stage of the life cycle.

• Symmetry is an attribute of an organism showing regularity in body parts on a plane or around an axis.
• In Phylum Echinodermata, the adult echinoderms are radially symmetrical but the larvae are bilaterally symmetrical. 

Hence, the correct option is B.

NCERT Reference: Topic: Phylum – Echinodermata” of chapter Animal Kingdom

• The insects belong to phylum Arthropoda and hence, the excretory organ is Malphighian tubules.
• Malphighian tubules are the main excretory organs in insects. They are a part of the insect digestive system and play a crucial role in maintaining the insect's internal balance of water and ions, as well as in excreting waste products from the body.

Malphighian tubules

Hence, the correct option is B.

NCERT Reference: Topic “Phylum – Arthropoda” of chapter Animal Kingdom.

Cnidarians, such as jellyfish, corals, and sea anemones, are known for having cnidoblasts (or cnidocytes), which are specialized cells that contain a stinging structure called a nematocyst. This feature is used for defense and capturing prey. Bilateral symmetry is characteristic of more advanced phyla like Chordata, the presence of a notochord defines Chordata, and a segmented body is a feature of Annelida and Arthropoda.

To evaluate the given assertion and reason, let's analyze each statement individually and then determine their relationship.

Assertion (A): Nematodes are pseudocoelomates.

Nematodes, also known as roundworms, are indeed pseudocoelomates. This means they have a body cavity that is not fully lined with mesodermal tissue.

Reason (R): Pseudocoelomates have a body cavity that is not fully lined with mesoderm.

This statement is correct. Pseudocoelomates have a body cavity called a pseudocoelom, which is only partially lined with mesoderm. In contrast, coelomates have a body cavity completely lined with mesoderm.

Now, let's determine if the reason correctly explains the assertion. The assertion states that nematodes are pseudocoelomates, and the reason provides a correct definition of what pseudocoelomates are.

Therefore, both the assertion and the reason are correct, and the reason correctly explains the assertion.

So, the correct answer is:

  4. Both (A) and (R) are true, and (R) is the correct explanation of (A).