Multicellular animals consist of four basic types of tissues that perform complex functions along with intercellular substances. Here is a collection of all important questions that are related to structural organisation of animals and are crucial for NEET 2023.
- Which of the following cells are not ciliated?
(a) Columnar epithelium
(b) Transitional epithelium
(c) Cuboidal epithelium
(d) Pseudostratified epithelium
Answer: (b)
Explanation: Epithelial tissues are of two types – simple and compound epithelium. Simple epithelium is further divided into squamous, cuboidal, columnar and pseudostratified tissues. Compound epithelium is divided into stratified and transitional epithelium.
Ciliated epithelium moves particles or mucus in a particular direction over the epithelium. It is seen in:
- Columnar cells (e.g, oviducts)
- Cuboidal cells (e.g, some parts of nephron)
- Pseudostratified cells (e.g, goblet cells)
Transitional epithelium is compound epithelium and hence they are always non-ciliated. E.g, urinary bladder.
- Which of the following tissues is the first to be formed in an embryo?
(a) Epithelial tissues
(b) Neural tissues
(c) Muscle tissues
(d) Connective tissues
Answer: (a)
Explanation: There are four types of animal tissues – epithelial tissues, connective tissues, neural tissue and muscular tissue.
Epithelial tissues are the first tissues to be formed in an embryo. They are large sheets of cells covering or lining all body surfaces.
- Which of the following layers may undergo keratinisation?
(a) Pseudostratified ciliated epithelium
(b) Transitional epithelium
(c) Cuboidal glandular epithelium
(d) Stratified squamous epithelium
Answer: (d)
Explanation: The outermost layer of the stratified squamous epithelium has a waterproof protein layer called keratin. Addition of the keratin layer is called keratinisation. This layer is impermeable to water and is resistant to abrasion. It is seen in the epidermal layer of the skin.
- Which of the following junctions allow the transfer of cardiac impulses from one fibre to another fibre?
(a) Tight junctions
(b) Intercalated discs
(c) Adherens junctions
(d) None of these
Answer: (b)
Explanation:
- Intercalated discs are communication junctions which allow the transfer of cardiac impulses from one fibre to another fibre. They are found in between adjacent cardiac muscle fibres.
- Tight junctions stop substances from leaking across the tissue.
- Adherens junctions cement the neighbouring cells together.
- Gap junctions facilitate cell communications by movement of ions and molecules between adjacent cells.
- Which one of the following cells are found in the structural tissue of the pinna of the ear?
(a) Osteocytes
(b) Chondrocytes
(c) Neuron
(d) Myofibril
Answer: (b)
Explanation: The pinna of the ear is made up of the specialised connective tissue called cartilage. These tissues are made up of cells called chondrocytes enclosed in small cavities within the matrix.
Osteocytes are bone cells that have a mineralised matrix. Neurons are cells of the nerve tissue that are made up of axons and dendrites. Myofibril is the basic unit of muscle cells that has a rod-like structure.
- Which of the following statements describes the cardiac muscle?
(a) Striated and involuntary
(b) Non-striated and involuntary
(c) Non-striated and voluntary
(d) Striated and voluntary
Answer: (a)
Explanation: The three types of muscle tissues are – skeletal muscle tissue, smooth muscle tissue and cardiac muscle tissue.
Cardiac muscle has alternate light and dark bands called striations, similar to skeletal muscle. They are not in control of the individual and are hence involuntary in nature.
- Which of the following structures in the neural tissue synthesises proteins?
(a) Myelin sheath
(b) Neurofibrils
(c) Synapse
(d) Nissl’s granules
Answer: (d)
Explanation: Nissl’s granules are particles found in the neuroplasm. They are irregular masses of rough endoplasmic reticulum (RER) and free ribosomes that are sites of protein synthesis.
- What is the junctional region between two neurons known as?
(a) Neurolemmocytes
(b) Synapse
(c) Myelin sheath
(d) Neurilemma
Answer: (b)
Explanation: A nerve impulse is transmitted from one neuron to another through a junction known as a synapse. Neurolemmocytes or Schwann cells form the myelin sheath. Myelin sheath is an insulating layer around the neurons of the peripheral nervous system. They are absent in the central nervous system. Neurilemma forms plasma membranes of the Schwann cells.
- What is the function of the tendon?
(a) Serves as a support framework for the epithelium
(b) Transport of the nutrients and gaseous substances
(c) Connects skeletal muscle to the bones
(d) Connects bones to bones
Answer: (c)
Explanation: Tendons are dense regular connective tissues that connect skeletal muscles to bones. Ligaments are dense regular connective tissues that connect bones to bones. Blood is a specialised fluid connective tissue that helps in the transport of nutrients and the gaseous substances to the different parts of the body. Areolar tissues are loose connective tissue present beneath the skin and serve as a support framework for the epithelium.
Refer:Difference Between Ligaments And Tendons
- ___________ are the spaces in which the bone cells are found.
(a) Lacunae
(b) Lamella
(c) Canaliculi
(d) Collagen fibres
Answer: (a)
Explanation: Lacunae are the spaces in which the bone cells are found. Lamellae are concentric layers of compact bone tissue which surround a central canal called Haversian canal. The fine network of the canal called canaliculi forms concentric layers around the Haversian canal. Canaliculi supply nutrients to the osteocytes (bone cells). Collagen is a type of structural protein which is secreted by the cells of the connective tissue. It forms the matrix of cartilage.
- Intervertebral disc is made up of
(a) calcified cartilage
(b) elastic cartilage
(c) hyaline cartilage
(d) fibrous cartilage
Answer: (d)
Explanation: There are three types of cartilage found –
- Hyaline cartilage: It is the most widespread cartilage that has a glass-like appearance. It is found in ribs, nose, larynx and trachea.
- Elastic cartilage: This type of cartilage provides strength and elasticity and is found in the external ear.
- Fibrous cartilage: This is the strongest cartilage that has many collagen fibres in it. It is found in intervertebral discs.
- Find the correct order of the parts of the alimentary canal in cockroaches.
(a) Mouth → Pharynx → Crop → Gizzard
(b) Mouth → Oesophagus → Pharynx → Gizzard
(c) Pharynx → Gizzard → Crop → Malpighian tubules
(d) Pharynx → Gizzard → Crop → Oesophagus → Malpighian tubules
Answer: (a)
Explanation: The alimentary canal of a cockroach consists of foregut, midgut and hindgut. The foregut consists of mouth → pharynx → crop → gizzard.
Malpighian tubules are excretory structures present at the junction of midgut and hindgut in cockroaches.
- How many of the given statements are true?
A. In a cockroach, the brain is represented by a supra-oesophageal ganglion that supplies nerves to the maxillary and labial palps.
B. The compound eyes are situated at the ventral surface of the head.
C. Each compound eye consists of 200 hexagonal ommatidia.
(a) 1
(b) 2
(c) 3
(d) 4
Answer: (a)
Explanation: The brain of a cockroach is supra-oesophageal ganglion that supplies nerves to antennae and compound eyes. The compound eyes are located at the dorsal surface of the head. Each of the eyes consists of 2000 hexagonal ommatidia.
- Assertion: In cockroaches, respiratory gases directly come in contact with various organs of the body.
Reason: Cockroaches do not have respiratory pigment.
(a) Both assertion and reason are correct and reason is the correct explanation of the assertion statement.
(b) Both assertion and reason are correct but reason is not the correct explanation of the assertion statement.
(c) Assertion is correct but reason is wrong.
(d) Both assertion and reason are incorrect statements.
Answer: (a)
Explanation: The blood of cockroaches is called hemolymph. It is a fluid connective tissue composed of corpuscles and a colourless fluid called plasma. It does not contain any respiratory pigment and therefore plays no role in respiration. The respiratory system consists of a network of trachea that open through 10 pairs of small holes called spiracles present on the lateral sides of the body.
These branching tubes called trachea carry oxygen from the air to all the parts. The opening of the spiracles are regulated by sphincters. Exchange of gases takes place at the tracheoles by diffusion.
- The structure of the body in earthworm is maintained by
(a) coelomic fluid
(b) clitellum
(c) setae
(d) metameres
Answer: (a)
Explanation: Unlike humans, earthworms have no skeleton. They have a coelomic cavity that is filled with a milkish fluid called coelomic fluid. This fluid makes the body segments turgid and helps in locomotion.
Clitellum forms the dark prominent band of glandular tissue in the 14th to 16th segment of the earthworm and secrete cocoon. Setae is an S-shaped chitinous structure that helps in locomotion. It is found in each body segment except the first, last and clitellar segments. The body of the earthworms is externally and internally segmented, called metameric segmentation.
- Match the following structures in earthworms to their location.
| Structure | Location | ||
|---|---|---|---|
| A. | Male genital pore | I. | 10th and 11th segment |
| B. | Female genital pore | II. | 14th segment |
| C. | Testes | III. | 18th segment |
| D. | Ovary | IV. | 12th – 13th intersegmental septum |
(a) A-I, B-IV, C-II, D-III
(b) A-III, B-I, C-II, D-IV
(c) A-II, B-III, C-IV, D-I
(d) A-III, B-II, C-I, D-IV
Answer: (d)
Explanation:
Testis sacs with testes → 10th and 11th segment
Ovary → 12th – 13th intersegmental septum
Female genital pore → 14th segment
Male genital pore → 18th segment
- Earthworms are bisexual but still cross-fertilisation is common in them. This is because
(a) spermatozoa of different earthworms are different
(b) spermatozoa and ova mature at different times in the same earthworm
(c) ova from other earthworms may be larger
(d) ova mature earlier than spermatozoa
Answer: (b)
Explanation: Earthworms are hermaphroditic organisms, i.e., both male and female reproductive organs are found in an individual. They are protandrous in nature, meaning that their male reproductive organs come to maturity before the females do. Both the organs are placed at different apertures, therefore, cross fertilisation is a common phenomena in such organisms.
Refer: Reproductive System Earthworm
- Frogs have the ability to breathe in different ways. Choose the correct answer related to respiration in frogs from the option given below.
(a) pulmonary and cutaneous respiration
(b) cutaneous and buccopharyngeal respiration
(c) pulmonary, tracheal, and buccopharyngeal respiration
(d) pulmonary, cutaneous, and buccopharyngeal respiration
Answer: (d)
Explanation: Frogs have three respiratory organs –
- Pulmonary respiration (lungs)
- Cutaneous respiration (skin)
- Buccopharyngeal respiration (lining of the mouth)
- Assertion: Frogs undergo aestivation and hibernation.
Reason: Frogs take shelter in deep burrows to protect themselves from extreme heat and cold.
(a) Both assertion and reason are correct and reason is the correct explanation of the assertion statement.
(b) Both assertion and reason are correct but reason is not the correct explanation of the assertion statement.
(c) Assertion is correct but reason is wrong.
(d) Both assertion and reason are incorrect statements.
Answer: (a)
Explanation: Frogs are cold-blooded animals (poikilotherms). In order to protect themselves from extreme temperatures, they undergo aestivation (summer sleep) and hibernation (winter sleep). They take shelter in burrows during aestivation and hibernation.
- Which of the following options is incorrect with reference to frogs?
(a) Vascular system – closed type
(b) Heart – three chambered
(c) Excretion – uricotelic
(d) Cranial nerves – 10 pairs
Answer: (c)
Explanation: The frog’s heart is composed of three chambers which includes two atria and one ventricle. Since blood flows through closed channels (blood vessels), the frogs have a closed vascular system. Frogs excrete nitrogenous wastes in the form of urea and are hence ureotelic animals. They have ten pairs of cranial nerves under the peripheral nervous system.
Keep visiting BYJU’S for more information related to NEET.
Recommended Video:
Also Read:
Comments