30 free MCQs on Structural Organisation in Animals with worked answers and explanations. The four basic animal tissue types (epithelial, connective, muscular, neural) and the cockroach as a model organism for organ-system level organisation.
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The four basic animal tissue types and their core functions: epithelial (covering/lining), connective (support and transport), muscular (movement), and neural (signal conduction).
Q1.
Which of the following is one of the four basic animal tissue types?
Answer: B. Epithelial tissue
Why: Animal tissues are classified into four basic types: epithelial, connective, muscular, and neural. Vascular, meristematic, and ground tissue are plant tissue terms.
Q2.
Which type of epithelium lines the alveoli of the lungs, allowing rapid gas diffusion?
Answer: C. Squamous epithelium
Why: Squamous epithelium consists of thin, flat cells forming a single layer, ideal for the rapid diffusion of gases as seen in the alveoli of the lungs and the lining of blood vessels.
Q3.
Tendons, which connect muscle to bone, are made of which tissue type?
Answer: B. Dense regular connective tissue
Why: Tendons are made of dense regular connective tissue, with collagen fibres aligned in rows, giving them great tensile strength to connect muscle to bone. Ligaments (made of similar tissue) connect bone to bone.
Q4.
Which muscle type is found exclusively in the heart?
Answer: C. Cardiac muscle
Why: Cardiac muscle is found only in the heart. It is striated like skeletal muscle but involuntary, with branched, uninucleate fibres joined by intercalated discs.
Q5.
Blood is classified as which type of tissue?
Answer: C. A fluid connective tissue
Why: Blood is a fluid connective tissue, made up of plasma along with red blood cells, white blood cells, and platelets, and functions in the transport of substances throughout the body.
Q6.
The body of a cockroach (Periplaneta americana) is divided into which three main parts?
Answer: A. Head, thorax, and abdomen
Why: The cockroach body, typical of insects, is divided into head, thorax (bearing legs and wings), and abdomen, all covered by a chitinous exoskeleton.
Q7.
Which structures help cockroaches breathe by opening to the exterior?
Answer: A. Spiracles
Why: Cockroaches respire through a network of tracheal tubes that open to the exterior through small pores called spiracles, delivering oxygen directly to tissues.
Q8.
Bone, a connective tissue, is distinguished from cartilage mainly by being:
Answer: A. Hard and mineralized, forming the rigid framework of the body
Why: Bone is a hard, mineralized connective tissue that forms the rigid framework of the vertebrate body, unlike cartilage, which is more flexible and compressible.
Q9.
Skeletal muscle, attached to bones and responsible for voluntary movement, appears under the microscope as:
Answer: B. Striated and multinucleate
Why: Skeletal muscle fibres show visible striations and are multinucleate, distinguishing them from smooth muscle (non-striated, uninucleate) and cardiac muscle (branched, with intercalated discs).
Q10.
The cockroach respires through openings on its body surface called:
Answer: A. Spiracles
Why: Spiracles are small openings along the body surface of the cockroach through which air enters and leaves the tracheal respiratory system.
Q11.
Which feature distinguishes simple epithelium from compound (stratified) epithelium?
Answer: B. Simple epithelium has a single cell layer suited to exchange/secretion; compound has multiple layers suited to protection
Why: Simple epithelium is a single layer of cells, located where absorption, secretion, or filtration occurs. Compound epithelium has multiple layers and serves a mainly protective role, e.g. the skin epidermis.
Q12.
Which combination correctly distinguishes skeletal muscle from cardiac muscle, despite both being striated?
Answer: A. Skeletal is voluntary and unbranched; cardiac is involuntary and branched with intercalated discs
Why: Skeletal muscle is voluntary, multinucleate, and made of unbranched fibres. Cardiac muscle, though also striated, is involuntary, uninucleate, and made of branched fibres joined end-to-end by intercalated discs.
Q13.
In the cockroach digestive system, what is the function of the gizzard?
Answer: C. Grinds food with the help of a thick cuticular lining
Why: The gizzard, part of the foregut, has a thick cuticular lining that grinds ingested food into smaller particles. Food is temporarily stored in the crop before reaching the gizzard, while the hepatic caecae secrete digestive enzymes in the midgut.
Q14.
Malpighian tubules in the cockroach are located at the junction of which two regions of the gut?
Answer: B. Midgut and hindgut
Why: Malpighian tubules are thin, finger-like outgrowths attached at the junction of the midgut and hindgut. They absorb nitrogenous waste (mainly uric acid) from the haemolymph and release it into the hindgut for elimination.
Q15.
Ciliated epithelium, found lining the trachea and bronchi, primarily functions to:
Answer: C. Sweep mucus and trapped particles away from the lungs
Why: Ciliated epithelium lines much of the respiratory tract; coordinated beating of cilia moves a layer of mucus, along with trapped dust and microbes, away from the lungs and toward the throat.
Q16.
Adipose tissue, a type of connective tissue, is specialized mainly for:
Answer: A. Storage of fat and insulation of the body
Why: Adipose tissue consists of cells specialized to store fat, providing energy reserves as well as insulation and cushioning for internal organs.
Q17.
Which feature distinguishes a tendon from a ligament, even though both are made of dense connective tissue?
Answer: D. Tendons connect muscle to bone, while ligaments connect bone to bone
Why: Tendons are dense connective tissue bands that attach skeletal muscle to bone, while ligaments are similar bands that connect one bone to another at joints.
Q18.
The cockroach has compound eyes, each made up of numerous individual visual units called:
Answer: D. Ommatidia
Why: Each compound eye in the cockroach is composed of many individual visual units called ommatidia, each capable of detecting light independently.
Q19.
Smooth muscle differs from skeletal muscle in that smooth muscle is:
Answer: D. Involuntary and non-striated, found in the walls of internal organs
Why: Smooth muscle is involuntary and lacks visible striations; it is found in the walls of internal organs like the gut and blood vessels, unlike the voluntary, striated skeletal muscle attached to bones.
Q20.
Nervous tissue is composed of neurons along with supporting cells. The main function of nervous tissue in the body is to:
Answer: A. Receive stimuli and transmit impulses rapidly throughout the body
Why: Nervous tissue is specialized to receive stimuli and rapidly transmit electrical impulses, coordinating responses throughout the body, unlike muscle or connective tissue.
Q21.
Malpighian tubules in insects and nephrons in the vertebrate kidney both remove nitrogenous waste from a body fluid. What term best describes this relationship between the two structures?
Answer: B. Analogous organs, since they perform a similar function but differ in structure and developmental origin
Why: Malpighian tubules and nephrons perform a similar excretory function (removing nitrogenous waste from a body fluid) but are structurally and developmentally unrelated, making them analogous organs rather than homologous ones.
Q22.
A tissue sample shows branched, uninucleate, striated fibres joined end-to-end at specialised junctions that allow synchronised contraction. Which tissue is this, and why does its structure matter functionally?
Answer: B. Cardiac muscle; the intercalated discs and branching let the electrical signal spread rapidly so the heart contracts as one coordinated unit
Why: This describes cardiac muscle. Its branched fibres and intercalated discs allow electrical impulses to spread rapidly between cells, so the entire heart contracts in a coordinated, wave-like manner rather than as disconnected fibres.
Q23.
Areolar connective tissue, found beneath the skin and around organs, is best described as performing which role?
Answer: C. A packing and support tissue that also allows some flexibility between structures
Why: Areolar tissue is a loose connective tissue that fills spaces, supports organs, and attaches skin to underlying muscles, while permitting some movement and flexibility.
Q24.
Neurons and glial cells both originate from the same embryonic tissue but differ chiefly in that:
Answer: A. Neurons are specialized for impulse conduction, while glia mainly support, nourish, and protect neurons
Why: Neurons are structurally adapted to generate and conduct electrical impulses, whereas glial cells provide structural support, nutrition, and protection without typically generating action potentials.
Q25.
In the cockroach, the haemocoel is a body cavity filled with haemolymph that bathes the tissues directly. This is a hallmark of which type of circulatory arrangement?
Answer: D. An open circulatory system, where blood is not always confined to vessels
Why: In the cockroach's open circulatory system, the dorsal heart pumps haemolymph into the haemocoel, where it bathes tissues directly rather than remaining confined within vessels throughout its circuit.
Q26.
Adipose connective tissue and cartilage both arise from mesenchyme, yet adipose tissue is classified separately because its cells mainly function to:
Answer: C. Store fat as an energy reserve and provide insulation, rather than to bear mechanical load
Why: Adipocytes in adipose tissue are specialized for storing triglycerides and providing thermal insulation, distinguishing them functionally from cartilage cells, which secrete a matrix to resist compression and support.
Q27.
The presence of intercalated discs is a structural feature unique to which tissue, and what does it enable functionally?
Answer: B. Cardiac muscle; they allow rapid electrical coupling between adjacent fibres for synchronized contraction
Why: Intercalated discs are specialized junctions between cardiac muscle fibres containing gap junctions, enabling rapid spread of electrical impulses so the heart contracts as a coordinated unit.
Q28.
Compound epithelium is typically found at body sites such as the skin epidermis and the lining of the oesophagus mainly because:
Answer: B. Multiple cell layers offer greater mechanical protection against abrasion and wear
Why: Compound (stratified) epithelium has several cell layers, providing strong mechanical protection at surfaces exposed to friction or wear, such as the skin and oesophageal lining, at some cost to its diffusion/secretion capacity.
Q29.
Within the same individual, skeletal muscle fibres are multinucleate and unbranched, whereas cardiac muscle fibres are branched and usually uninucleate or binucleate. This structural difference relates functionally to:
Answer: B. Cardiac branching, which helps spread the contraction wave through the heart in a coordinated way; skeletal fibres are built instead for strong, voluntary, directional pulls
Why: Cardiac muscle's branched fibres, linked by intercalated discs, allow impulses to spread through the heart for synchronized pumping, while skeletal muscle's long, unbranched, multinucleate fibres are suited to strong, directional, voluntary contraction.
Q30.
Hyaline cartilage at the articulating ends of long bones reduces friction during movement mainly because its matrix is:
Answer: A. Smooth and somewhat compressible, formed of chondrocytes embedded in a flexible but firm ground substance
Why: Hyaline cartilage has a smooth, firm yet slightly compressible matrix secreted by chondrocytes, which reduces friction and absorbs shock at joints, unlike bone, which is rigid and heavily mineralized.