Structural Organization In Animals Question And Answers

Biology Class 11 WBCHSE Structural Organisation In Animals Question And Answers

Question 1. What are animal tissues?
Answer: The cells in an animal body which are identical in structure, origin and function, organise to form animal tissues.

Question 2. What is histology?
Answer: The branch of science that deals with the structure, origin, function, variation etc., of tissues is called histology.

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Question 3. Name the four main tissues in an animal body. State the embryonic origin of these tissues.
Answer: The four main animal tissues are—epithelial tissue, connective tissue, muscular tissue and nervous tissue.

The embryonic origin of these tissues is—

1. Epithelial tissue—ectoderm, endoderm, mesoderm
2. Connective tissue—mesoderm
3. Muscular tissue—mesoderm
4. Nervous tissue—ectoderm.

Question 4. Which tissue lacks blood vessels?
Answer: Epithelial tissue lacks blood vessels. The cells of epithelium obtain nutrition and other necessary substances through diffusion from the intercellular fluid.

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Question 5. What is a brush border?
Answer: In most cases, the free surface of epithelial tissue folds to form tiny finger-like structures which are known as microvilli.

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Class 11 Biology Solutions

The epithelium that is lined by microvilli appears like a brush and so is called a brush border.

Question 6. Which chemical constituent is secreted by goblet cells?
Answer: Goblet Cell Mainly Sexreates Mucin.

Question 7. Compare the secretion process of holocrine, apocrine and merocrine glands.
Answer:

Question 8. What are the main parts of connective tissue?
Answer: The main components of connective tissue are- cells, matrix and fibres. Besides, blood vessels are associated with connective tissue. gill

Question 9. Name some immune cells of connective tissue.
Answer: Macrophages, mast cells etc., are some immune cells of connective tissue.

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Question 10. What fibres are present in areolar connective tissue?
Answer: Two types of fibres are seen in areolar connective tissue

White fibres: Collagen-containing, white, unbranched, thick fibres.

Yellow fibres: Elastin-containing, yellow, branched, thin fibres.

Question 11. Name three main cartilages.
Answer: Three main cartilages are—hyaline cartilage, fibrous cartilage and elastic cartilage.

Question 12. What are red and white muscles?
Answer: Mammals have two types of striated/skeletal muscles—red muscles and white muscles.

Class 11 Biology Solutions

Myoglobin containing red-coloured, slow-contracting muscles are called red muscles. These muscles work slowly for a long time without getting fatigued. Example muscles of the back.

Myoglobin lacking pale-coloured, fast-contracting muscles are called white muscles. These muscles work fast for a short time. Example muscles of eye orbit.

Question 13. Why is skeletal muscle called striated?
Answer: Skeletal muscle fibres have alternate light and dark bands. So, skeletal muscle is called striated muscle.

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Actually, the parts of the muscle fibres that have more actin protein appear dark. Again, the parts of the muscle fibres that have more myosin protein appear light.

Question 14. Which contractile protein fibres are present in striated muscles?
Answer: Striated muscle has two contractile protein fibres— thin fibres or actin fibres and thick fibres or myosin fibres.

Question 15. Name the neuroglial cells of the nervous system,
Answer: The neuroglial cells are—oligodendrocytes, astrocytes, microglia and ependymal cells.

Question 16. What are the divisions in each body segment of a cockroach?
Answer: Each body segment of a cockroach has four chitinous parts—tergum (dorsal), sternum (ventral), and pleurite (two lateral parts).

Question 17. What is elytra?
Answer: A pair of chitinous wings that originate from the j dorsal surface of the mesothorax is called elytra. It helps the cockroach to change direction.

Question 18. State the position of crop and gizzard.
Answer: In cockroaches, the crop is located at the posterior part of the alimentary canal and gizzard is located next to the crop.

Question 19. Name the parts of the mouth of a cockroach.
Answer: The parts of the mouth of a cockroach are- maxillae (1 pair), mandible (1 pair), labium, labrum, and hypopharynx.

Question 20. Why isn’t a respiratory pigment present in cockroaches?
Answer: Cockroaches lack any respiratory pigment. It is because atmospheric air enters the body through spiracles and is directly transported to tissues through the trachea and tracheoles. So, it does not require any pigment.

Question 21. What type of metamorphosis occurs in cockroaches? What is the name of the moulting hormone?
Answer: Metamorphosis in cockroaches is of hemimetabolous type and the moulting hormone is ecdysone.

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Question 22. What are Ostia? Mention their function.
Answer: Ostia: Openings in the lateral surface of each cavity of the heart in cockroaches are called ostia. These are covered by valves.

Function: Valves allow the flow of haemolymph from the pericardium to the heart through the ostia but prevent its backflow.

Class 11 Biology Solutions

Question 23. What are alary muscles?
Answer: These are a kind of muscles, located on both sides of the heart of a cockroach. They help the heart to contract and relax. Cockroach possesses 12 pairs of alary muscles.

Question 24. What is the collateral gland?
Answer: The branched gland present within the fat bodies in the ovariole of female cockroaches is called the collateral gland. The secretions from this gland form ootheca.

Question 25. What is hepatic caecae?
Answer: The eight fine tubules present at the junction of the gizzard and mesenteron are called hepatic caecae.

The frontal end of these tubules is closed and the distal ends open into the alimentary canal. Digestive juices are secreted by these glands.

Biology Class 11 WBCHSE Structural Organisation In Animals Multiple Choice Questions

Question 1. Which type of tissue correctly matches its location?

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Answer: 4.

Question 2. Which of the following features is not present in Periplaneta americana?

1. Indeterminate and radial cleavage during embryonic development
2. Metamerically segmented body
3. Schizocoelom as body cavity
4. Exoskeleton composed of N-acetylglucosamine

Answer: 1. Indeterminate and radial cleavage during embryonic development

Question 3. The body cells in cockroaches discharge their nitrogenous waste in the haemolymph mainly in the form of—

1. Calcium carbonate
2. Ammonia
3. Potassium urate
4. Urea

Answer: 3. Potassium urate

Question 4. Choose the correctly matched pair—

1. The inner lining of salivary ducts—ciliated epithelium
2. The moist surface of the buccal cavity—glandular
3. Epithelium
4. Tubular parts of nephrons—cuboidal epithelium
5. The inner surface of bronchioles—squamous epithelium

Answer: 3. Tubular parts of nephrons—cuboidal epithelium

Class 11 Biology Solutions

Question 5. Choose the correctly matched pair—

1. Tendon—Specialised connective tissue
2. Adipose tissue—Dense connective tissue
3. Areolar tissue—Loose connective tissue
4. Cartilage—Loose connective tissue

Answer: 4. Cartilage—Loose connective tissue

Question 6. The inner surface of the bronchi, bronchioles and fallopian tubes are lined by—

1. Cuboidal epithelium
2. Columnar epithelium
3. Squamous epithelium
4. Ciliated epithelium

Answer: 4. Ciliated epithelium

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Question 7. What type of cartilaginous tissue is found in the intervertebral discs?

1. Costal cartilage
2. Hyaline cartilage
3. White fibrous cartilage
4. Yellow elastic cartilage

Answer: 3. White fibrous cartilage

Question 8. The lining of intestine and kidneys in humans is—

1. Keratinised
2. Brush border
3. Ciliated
4. None of these

Answer: 2. Brush border

Question 9. The vagina, oesophagus, and urethra contain which type of tissue?

1. Stratified squamous epithelium
2. Simple squamous epithelium
3. Ciliated epithelium
4. Columnar epithelium

Answer: 1. Stratified squamous epithelium

Class 11 Biology Solutions

Question 10. The inner lining of the ducts of sweat glands and pancreatic duct is formed by this epithelium—

1. Stratified cuboidal
2. Stratified non-keratinised squamous
3. Transitional
4. Pseudostratified

Answer: 1. Stratified cuboidal

Question 11. Dense regular connective tissue is present in—

1. Ligament and tendons
2. The joint capsule and Wharton’s jelly
3. Periosteum and endosteum
4. Pericardium and heart valves

Answer: 1. Ligament and tendons

Question 12. The structural unit of bone is—

1. Chondrin
2. Cyton
3. Osteon
4. Ossein

Answer: 3. Osteon

Question 13. Read the following statements and choose the correct answer—

1. Gap junctions cement adjacent cells together.
2. Areolar tissue contains fibroblasts, macrophages and mast cells.
3. Tight junctions facilitate the cells to communicate with each other.
4. Adhering junctions helps to stop substances from leaking across tissues.
5. Cells of connective tissue except blood secrete fibres of structural proteins called elastin,

Choose the Correct Option

1. 1, 2 and 3 only are incorrect
2. 2, 3 and 4 only are incorrect
3. 3 and 5 only are incorrect
4. 1, 2 and 5 only are incorrect
5. 2, 4 and 5 are incorrect

Answer: 1. 1, 2 and 3 only are incorrect

Class 11 Biology Solutions

Question 14. Which of the following is not a sensory structure in cockroaches?

1. Antennae
2. Eyes
3. Anal cerci
4. Maxillary palps
5. Proventriculus

Answer: 5. Proventriculus

Question 15. Choose the wrongly matched pair regarding the position of reproductive structure in earthworms.

1. Testes—10th and 11th segments
2. Spermatheca—6th and 9th segments
3. Male genital pore—9th segment
4. Ovaries—Intersegmental septum of 12th and 13th segments

Answer: 3. Male genital pore—9th segment

Question 16. Female genital pore—14th segment In cockroaches, arthrodial membrane—

1. Forms the hind wings
2. Covers the compound eyes
3. Forms the hypopharynx
4. Forms the tegmina
5. Joins the sclerites

Answer: 5. Joins the sclerites

Question 17. Which of the following animals has enucleated erythrocytes?

1. Earthworm
2. Sepia
3. Frog
4. Rat

Answer: 4. Rat

Question 18. The outer covering of cartilage is called—

1. Peritoneum
2. Periosteum
3. Endosteum
4. Perichondrium

Answer: 4. Perichondrium

Question 19. Bone marrow is absent in—

1. Reptiles
2. Amphibians
3. Fishes
4. Birds

Answer: 4. Birds

Class 11 Biology Solutions

Question 20. Debove’s membrane is a layer of—

1. Muscular tissue
2. Epithelial tissue
3. Connective tissue
4. All of these

Answer: 3. Connective tissue

Question 21. Cardiac muscle is found in—

1. Pericardium
2. Endocardium
3. Myocardium
4. Peritoneum

Answer: 3. Myocardium

Question 22. The H-zone in skeletal muscle fibre is due to—

1. The absence of myofibrils in the central portion of a band
2. The central gap between myosin filaments in the a-band
3. The central gap between actin filaments extending through myosin filaments in the a-band
4. Extension of myosin filaments in the central portion of the a-band

Answer: 3. The central gap between actin filaments extending through myosin filaments in the a-band

Class 11 Biology WBCHSE Structural Organisation In Animals Short Answer Type Questions

Question 1. What is a basement membrane?
Answer: The layer of collagenous fibres present between the upper epithelial layer and lower subepithelial loose connective tissue is called the basement membrane.

Question 2. What is epithelial tissue?
Answer: The animal tissue which forms the covering of the body and the inner and outer walls of some organs is called the epithelial tissue.

Question 3. What is germinal epithelium?
Answer: The epithelial tissue that helps in the formation of gametes and lines the testis and ovary is called germinal epithelium.

Question 4. What is endocardium?
Answer: The squamous epithelium in the inner wall of the heart is called endocardium.

Question 5. What are the cellular components of blood?
Answer: The cellular components of blood are red blood corpuscles (RBCs), white blood corpuscles (WBCs) and blood platelets.

Question 6. What type of tissue occurs in hairs, nails and horns?
Answer: Stratified cornified squamous epithelial tissue {occurs in hairs, nails and horns.

Question 7. Which is the hardest structure in our body?
Answer: Bone is the hardest structure in our body.

Question 8. State the function of Malphighian tubules,
Answer: Malpighian tubules are the main excretory organs of cockroaches. They collect excretory substances from body fluid and transport them to the alimentary canal.

Question 9. What is endothelium?
Answer: All tissue on the inner wall of blood vessels and lymphatic vessels is called endothelium.

Question 10. What is glandular tissue?
Answer: The epithelial tissue that takes part in secretory functions is called glandular tissue.

Question 11. What is a mixed gland? Give an example.
Answer: The glands which are constituted of both endocrine and exocrine components are called mixed glands. For example, the pancreas is a mixed gland.

Question 12. What do you mean by synapse?
Answer: The junction between the axon of one neuron and the dendron of another neuron where neurotransmitters are released is called a synapse.

Question 13. Mention the main function of epithelial tissue.
Answer: The main function of epithelial tissue is to provide protection from injuries.

Question 14. What is a bipolar neuron?
Answer: The neuron which has one dendron and one axon extending from the cyton is called a bipolar neuron.

Question 15. What is astrocyte?
Answer: Supporting cells of the peripheral nervous system that provide nutrition to a neuron are called astrocytes.

Question 16. What is myosin?
Answer: The contractile protein of myofilaments in muscles is called myosin.

Question 17. What is a sarcomere?
Answer: The contractile unit of muscles is known as sarcomere.

Question 18. Name one plasma protein.
Answer: y-globulin protein is a plasma protein.

Question 19. Mention the name of the contractile proteins of the muscles.
Answer: Actin and myosin are the contractile proteins in the muscles.

Question 20. Mention the function of adipose cells.
Answer: Adipose cell stores fat and provides insulation to the body, thereby preventing loss of heat.

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Question 21. What is a neurilemma?
Answer: The outermost covering made up of Schwann cells, that surrounds the axon is called neurilemma.

Question 22. What is an intercalated disc?
Answer: Sarcolemma of the cardiac muscle fibre is thickened at intervals to form plate or disc-like structures called intercalated discs.
They appear as dark lines that separate the individual cardiac muscle cells from one another.

Question 23. Mention the scientific name of the American cockroach.
Answer: The scientific name of the American cockroach is Periplaneta americana.

Question 24. Mention the phylum and class of cockroaches.
Answer: Cockroach belongs to the phylum Arthropoda and class Insecta.

Question 25. What role is played by the gizzard of cockroach?
Answer: Gizzard contains chitinous teeth which cut and chum the food into pieces.

Question 26. How many spiracles are found in a cockroach?
Answer: 10 pairs of spiracles are found in cockroaches.

Question 27. Name the different mouth parts of the cockroach.
Answer: The labrum, mandible, maxillae, labium and hypopharynx are the mouth parts of cockroaches.

Question 28. How many segments are found in the thorax of a cockroach?
Answer: Three segments are present in the thorax of the cockroach.

Question 29. How many segments are present in the abdomen of a cockroach?
Answer: Ten segments are present in the abdomen of cockroaches.

Question 30. Name the different digestive glands of cockroaches.
Answer: The digestive glands of cockroaches are salivary gland, glandular cells of midgut epithelium and hepatic caecae.

Question 31. What is the function of the mandible of a cockroach?
Answer: The mandible acts as the palate and helps in chewing, crushing and grinding the food.

Question 32. How many segments are there in the leg of cockroach?
Answer: The leg of the cockroach has five segments.

Question 33. What do you mean by haemocoel?
Answer: The haemolymph-filled body cavity of a cockroach is called a haemocoel.

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Question 34. What is anal style?
Answer: The paired appendages articulated with a ninth abdominal segment of male cockroaches are called anal style.

Question 35. Where are the sclerites present in cockroaches?
Answer: Sclerites are present in the exoskeleton of cockroaches.

Question 36. Which mouth part of the cockroach is comparable to our tongue?
Answer: The Hypopharynx of cockroaches is comparable to the human tongue.

Question 37. What is the use of crops of cockroach?
Answer: Crop stores food for cockroaches.

Question 38. How many sinuses are found in cockroaches?
Answer: Three sinuses are present in cockroaches. They are dorsal, middle and ventral sinuses.

Question 39. A muscular fibre tapers at both ends and does not show striations. Name the muscle fibre.
Answer: Smooth or non-striated muscle fibres taper at both ends and do not show striations.

Question 40. How does a gap junction facilitate the intercellular communication?
Answer: Gap junction connects adjacent cells through the cytoplasm and thus allows cellular communication.

Question 41. Justify the name ‘pseudostratified epithelium’.
Answer: In the case of pseudostratified epithelium, all tire cells touch the basement membrane but may or may not reach the free surface.

The nuclei of these cells are arranged in different planes. As a result, they seem to form several layers, giving a pseudostratified appearance.