Structural Organisation in Animals

Male frogs can be distinguished from female frogs due to the presence of vocal sacs and copulatory pad on first digit of fore limbs.

Bulging eyes, webbed digit in feet and olive green-coloured skin with dark irregular spots are common in both male and female frogs.

A. Correct → In frogs, the special venous connection between liver and intestine is called the hepatic portal system.

B. Incorrect → There are ten pairs of cranial nerves arising from the brain of frog.

C. Correct → In female frogs, the uterus and oviduct open separately in the cloaca.

D. Incorrect → In frogs, the midbrain consists of the optic lobes.

• The hindbrain consists of cerebellum, and medulla oblongata.

E. Correct → In frogs, a triangular structure called sinus venosus joins the right atrium.

Thus, correct statements are (A), (C) and (E)

In frogs, there are ten pairs of cranial nerves arising from the brain.

In pseudocoelomates, the body cavity features mesodermal tissue along the body wall, but it is not fully lined with mesoderm, as there is no mesodermal tissue present towards the alimentary canal.

Schizocoelomates: These animals have a body cavity, or coelom, which develops from a split within the mesoderm, the middle germ layer during embryonic development.

Acoelomates: Animals in this category lack a coelom entirely; they do not have a body cavity between their gut and body wall.

Spongocoel: This term refers to the central cavity characteristic of sponges, which are sessile aquatic animals.

The correct statement about the type of junction and their role in our body is Option B: Tight junctions help to stop substances from leaking across a tissue.

Let's break down why this is correct and why the other options are incorrect:

Tight junctions are indeed responsible for forming a seal between cells, preventing the passage of fluids and molecules between them. This is crucial for maintaining the integrity of tissues and organs. Imagine the lining of your stomach or intestines - tight junctions ensure that digestive juices and enzymes don't leak out and cause damage to surrounding tissues.

Here's why the other options are incorrect:

Option A: Adhering junctions facilitate the cells to communicate with each other.

This statement is incorrect. While adhering junctions do help in holding cells together, they are primarily involved in providing structural support and mechanical strength to tissues. Communication between cells is primarily facilitated by gap junctions, not adhering junctions.

Option C: Tight junctions help to perform cementing to keep neighbouring cells together.

This statement is partially correct, but incomplete. While tight junctions do play a role in holding cells together, their primary function is to form a barrier, preventing leaks. Adhering junctions are more specifically responsible for cementing cells together.

Option D: Gap junctions help to create gaps between the cells and tissues.

This statement is completely incorrect. Gap junctions actually form channels between cells, allowing for the direct passage of ions, small molecules, and even electrical signals. These channels are essential for cell-to-cell communication and coordination in various tissues like heart muscle and smooth muscle.

In summary, tight junctions act as barriers, adhering junctions provide structural support, and gap junctions enable communication between cells.

The correct answer is option (D) as

A. Collateral gland Present in female cockroaches

It is a pair of gland that secrete the hard egg case or ootheca

B. Mushroom gland Absent in female cockroaches

Present in males in the $6^{\text {th }}$ to $7^{\text {th }}$ abdominal segments

C. Spermatheca Present in female cockroaches in the $6^{\text {th }}$ abdominal segment

D. Anal style Absent in female cockroaches

Present in males and project backwardly from $9^{\text {th }}$ sternum

E. Phallic gland Absent in female cockroaches

Present in males as a large club shaped gland located below the ejaculatory duct and reaches anteriorly up to the $5^{\text {th }}$ abdominal segment.

Thus, only structures represented by 'A' and 'C' are present in female cockroaches.

Whereas, structures indicated by 'B', 'D' and 'E' are present in males. Options (A) and (B) are incorrect as these structures are present in males.

Option (C) is incorrect as it represents only a single structure which is present in female cockroaches.

The correct answer is Option B: A, B, C and E only.

Let's break down why:

Connective Tissues that Secrete Collagen or Elastin:

• Cartilage (A): Cartilage cells, called chondrocytes, produce a matrix rich in collagen fibers, providing its structure and flexibility. Some types of cartilage also contain elastin fibers for added elasticity.
• Bone (B): Bone cells, called osteoblasts, secrete a matrix containing collagen fibers, which provide tensile strength, and calcium phosphate crystals, which provide hardness.
• Adipose Tissue (C): While primarily composed of fat cells (adipocytes), adipose tissue also contains a network of collagen fibers that provide structural support and help maintain the tissue's shape.
• Areolar Tissue (E): Areolar tissue is a loose connective tissue with a rich network of collagen and elastin fibers. These fibers provide support, elasticity, and allow for the passage of blood vessels and nerves.

Blood (D): Blood is a fluid connective tissue. While it has proteins, it doesn't directly secrete collagen or elastin fibers. Its primary components are plasma, red blood cells, white blood cells, and platelets.

Therefore, the connective tissues that secrete collagen or elastin are cartilage, bone, adipose tissue, and areolar tissue, making Option B the correct answer.

Here's the breakdown of the matching between the types of epithelium and their locations:

(A) Squamous Epithelium:

Squamous epithelium is characterized by thin, flattened cells. This structure makes it ideal for diffusion and filtration. It's found in the walls of blood vessels (III), lining the alveoli of the lungs, and the lining of blood capillaries.

(B) Ciliated Epithelium:

Ciliated epithelium is characterized by cells possessing hair-like projections called cilia. These cilia beat rhythmically to move fluids or particles across the surface. It's found in the inner surface of Fallopian tubes (IV), trachea, and bronchi to propel mucus and foreign particles.

(C) Glandular Epithelium:

Glandular epithelium is specialized for secretion. It forms glands that release various substances like hormones, enzymes, and mucus. Goblet cells of the alimentary canal (I) are a prime example of glandular epithelium, as they secrete mucus.

(D) Compound Epithelium:

Compound epithelium is composed of two or more layers of cells. It provides protection and helps with secretion and absorption. While it can be found in the alimentary canal, it's not a definitive location.

Therefore, the correct matching is:

Option D: A-III, B-IV, C-I, D-II

The correct answer is Option B.

Anal cerci in both male and female cockroaches are located at the base of the $10^{\text {th }}$ abdominal segment of their bodies. The cerci are a pair of long, filamentous, sensory appendages that help cockroaches detect movements in the air, which warns them of approaching threats from behind, such as predators. This placement provides an effective mechanism for detecting environmental changes directly around the cockroach's posterior, enhancing their ability to quickly respond and escape threats. The location on the $10^{\text {th }}$ segment is typical and consistent in all cockroaches across different species.

The digestive system of a cockroach consists of several specialized structures that perform specific functions:

• Crop is a part of the alimentary canal where food is stored temporarily. This aligns with the description for List I "A. The structures used for storing of food". Thus, A corresponds to IV (Crop).
• Gastric Caeca are blind tubules located at the junction of the foregut and the midgut in insects. These tubules secrete enzymes and provide an increased surface area for digestion and absorption. This fits the description for List I "B. Ring of 6-8 blind tubules at junction of foregut and midgut". Hence, B corresponds to II (Gastric Caeca).
• Malpighian tubules are thin filamentous structures present at the junction of the midgut and hindgut. They are primarily involved in excretion and osmoregulation. They match the description for List I "C. Ring of 100-150 yellow coloured thin filaments at junction of midgut and hindgut". Thus, C corresponds to III (Malpighian tubules).
• Gizzard, also known as the proventriculus, is equipped with hard chitinous plates that grind the food mechanically. This description fits List I "D. The structures used for grinding the food". Therefore, D corresponds to I (Gizzard).

By collaborating all this information, the correct answer is:

Option A: A-IV, B-II, C-III, D-I

To match List I (types of epithelium) with List II (examples where these epithelia are found), we need to understand the characteristics and common locations of each type of epithelial tissue.

Here's the clarification for each match:

Unicellular glandular epithelium: This refers to single cells that function as glands, such as goblet cells. They are typically found in epithelial linings where they secrete mucus; within the digestive tract, goblet cells are common components.

Compound epithelium: This type is characterized by multiple layers of cells and is primarily protective. Common examples include skin and the inner lining of the mouth which needs protection against mechanical and chemical stress.

Multicellular glandular epithelium: This is found in glands composed of many cells. Examples include the salivary glands, pancreas, etc., where multiple cells work together to produce and secrete substances like enzymes and saliva.

Endocrine glandular epithelium: These glands are ductless and release hormones directly into the blood. An example of such a gland is the pancreas, which not only acts as an exocrine gland by producing digestive enzymes but also functions endocrinologically by regulating blood sugar levels through insulin and glucagon production.

Based on the above understanding:

• A (Unicellular glandular epithelium) matches with III (Goblet cells of alimentary canal).
• B (Compound epithelium) matches with IV (Moist surface of buccal cavity).
• C (Multicellular glandular epithelium) matches with I (Salivary glands).
• D (Endocrine glandular epithelium) matches with II (Pancreas).

Thus, the correct answer is Option C: A-III, B-IV, C-I, D-II.

Cockroaches are uricotelic organisms. The process of excretion in cockroaches is performed by Malpighian tubules, which are part of the insect's excretory system. These tubules are lined by glandular and ciliated cells, which absorb nitrogenous waste products and convert them into uric acid. This uric acid is then excreted out through the hindgut.

The nature of the nitrogenous waste excreted can be species-specific and is often influenced by the organism's environment and water availability. For instance, many bony fishes, aquatic amphibians, and aquatic insects, which have abundant access to water, are ammonotelic and excrete waste in the form of ammonia. In contrast, mammals, many terrestrial amphibians, and marine fishes, which live in environments where water conservation is critical, are ureotelic and excrete waste in the form of urea.

Given these details, the correct answer to the question "The Cockroach is:" would be Option B : Uricotelic only.

The correct answer is Option D : Both Statement I and Statement II are false.

In a cockroach :

1. The first pair of wings (forewings or tegmina) are not transparent and prothoracic in origin, as stated in Statement I. Instead, they are opaque, dark, leathery and originate from the mesothorax.




2. The second pair of wings (hind wings) are not opaque, leathery and mesothoracic in origin, as stated in Statement II. Instead, they are transparent, membranous and originate from the metathorax.

Option D : (A)-(II), (B)-(III), (C)-(IV), (D)-(I) is correct.

Explanation :

(A) Columnar epithelium : This type of epithelium consists of tall, slender and column-like cells. It's found in the inner lining of the stomach and intestine where it aids in secretion and absorption. So, (A) matches with (II).

(B) Ciliated epithelium : These are typically columnar or cuboidal cells that have cilia (small hair-like projections) on their surface. Ciliated epithelium is usually found in the bronchioles (air passages in the lungs) and in the fallopian tubes in females. The cilia help to move mucus and other substances. So, (B) matches with (III).

(C) Squamous epithelium : Squamous cells are thin and flat, similar in shape to fish scales (the word "squamous" means scaly). This type of epithelium forms the endothelium (the lining of the heart, blood vessels, and lymphatic vessels). So, (C) matches with (IV).

(D) Cuboidal epithelium : These cells are cube-shaped and are most commonly found in the ducts of glands and kidney tubules, where they assist with secretion and absorption. So, (D) matches with (I).

The correct answer is Option A : Both Statement I and Statement II are false.

Explanation : Ligaments are a type of dense regular connective tissue, not irregular. They connect bones to other bones, providing stability and support.

On the other hand, cartilage is a type of specialized connective tissue that is not classified as dense. It's composed of cells called chondrocytes which are embedded in a matrix of collagen and elastic fibers. It's neither dense regular nor dense irregular tissue.

Therefore, both statements I and II are incorrect.

Option (B) is the answer because,

In cockroaches, excretion is primarily accomplished by Malpighian tubules, which are not listed in the provided options. However, among the provided options, urecose glands, nephrocytes, and the fat body do participate in excretory processes to some degree.

Urecose glands are present in male cockroach of some species. They synthesise uric acid. Nephrocytes are large, colourless, ovoid, binucleate cells attached to the dorsal diaphragm in the body cavity. Fat body accumulates, produces and stores uric acid.

Phallic gland is the structure of male reproductive system of cockroach and it secretes the outer layer of spermatophore. Collaterial gland is the structure of female reproductive system of cockroach and it secretes the hard egg-case or ootheca around fertilised eggs.

Option (A) is the correct answer because anal styles are present in male cockroaches and absent in female cockroaches.

Option (B), (C) and (D) are not the correct answers because sclerites, anal cerci and dark brown body colour are common features of both male and female cockroaches.

Option (4) is the correct answer as ciliated epithelium is mainly present in the inner lining of hollow organs like bronchioles and fallopian tubes.

Option (1) is incorrect as stratified squamous epithelium covers moist surfaces such as those of buccal cavity, pharynx and oesophagus.

Option (2) is incorrect as simple squamous epithelium is found in the walls of blood vessels and air sacs of lungs.

Option (3) is incorrect as simple columnar epithelium is found in the lining of stomach and intestine.

Option (b) is the correct answer because

(a) Crop – Responsible for storage of food

(b) Proventriculus – Grinding the food particles

(c) Hepatic caecae – Secretion of digestive juice

(d) Malpighian tubules – Removal of nitrogenous waste

Option (b) is the correct answer because statements (a), (b) and (d) are correct.

$\bullet$ Bones are the hardest tissue of our body that support and protect softer tissues and organs.

$\bullet$ Limb bones serve weight bearing function.

$\bullet$ Adipose tissue is a type of loose connective tissue specialised to store fats.

$\bullet$ Option (a) is incorrect because statement (e) is false as tendons attach bones to muscles.

$\bullet$ Option (c) is incorrect because statement (c) is false as bone marrow in some bones is the site of production of blood cells.

$\bullet$ Option (d) is incorrect because this option includes statement (c) which is false.

Option (a) is correct answer because hepatic caeca are responsible for secretion of digestive juices in cockroach and it does not participate in excretion. Urecose glands in male cockroach, Malpighian tubules and fat bodies in both male and female cockroach are considered as excretory structures.

Option (d) is the correct answer because two additional chambers like crop and gizzard in alimentary canal are present in birds.

Pavo (Peacock), Psittacula (Parrot), Corvus (Crow) and Columba (Pigeon) are birds.

Option (a), (b) and (c) are incorrect because Catla is a bony fish, Crocodilus, Chameleon and Bangarus are reptiles, Bufo is an amphibian and Balaenoptera is an aquatic mammal.

Option (d) is the correct answer as neuroglia are a part of nervous tissue.

$\bullet$ Neuroglia are the supportive cells of nervous tissue. They make up more than half the volume of neural tissue. Neurons, the unit of neural system are excitable cells.

$\bullet$ Cartilage and blood are specialised type of connective tissues.

$\bullet$ Adipose tissue is a type of loose connective tissue.

Option (b) is the correct answer because tegmina or forewings (the first pair of wings) in cockroach arises from mesothorax.

Options (a), (c) and (d) are incorrect because no wing arises from prothorax and hindwings arise from metathorax.

Option (a) is the correct answer because

Ciliated epithelium is mainly present in the inner surface of hollow organs like bronchioles and fallopian tubes. The function is to move particles or mucus in a specific direction over the epithelium.

Some of the columnar or cuboidal cells get specialised for secretion and are called glandular epithelium. Goblet cells are unicellular glands.

Tendons are dense regular connective tissues. They attach skeletal muscles to bones.

Adipose tissue is a type of loose connective tissue located mainly beneath the skin. The cells of this tissue are specialised to store fats.