Structural Organisation In Animals(12th Grade > Biology ) Questions and Answers
Explanation:-
Answer: Option B. -> Tight junction:
B
Tight Junctions:Occur in cells that are joined by collars of tightly fused membranes. Molecules cannot penetrate or spread through cracks in between cells.
Example includesLining of the intestine (the only way molecules can get past is through controlled channels or carrier molecules in plasma membrane).
Explanation:-
Answer: Option D. -> All of the above:
D
Marophage is a large phagocytic cell found in stationary form in the areolar tissues or as a mobile white blood cell, especially at sites of infection.Amacrophagehas the ability to locate and 'eat' particles, such as bacteria, viruses, fungi, and parasites.Macrophagesare born from white blood cells called monocytes, which are produced by stem cells in our bone marrow.
Explanation:-
Answer: Option B. -> Neuroglia:
B
Neurons contain axons (long, slender projections from the cells that conduct electrochemical impulses or action potentials).
Neuroglia: 1. These are supporting cells of nervous tissue.
Neurogliamake upabouthalf the volumeof the CNS. - smallerthanneurons, and they are 5 to 50 timesmorenumerous
Explanation:-
Answer: Option D. -> Matrix:
D
Matrixis the material in animal or plant cells, in which more specialised structures are embedded, and a specific part of the mitochondrion The internal structure ofconnective tissuesis an extracellular matrix.
Explanation:-
Answer: Option D. -> Epithelial cells have spaces between them.:
D
The whole body surface is covered by theepithelial tissuewhich comprise of closely packed cells arranged in one or even more layers. The main responsibility of this tissue is to cover the whole body surface-externally and internally. The tissue which is present on the surface of interior body is called as endothelium. Theepithelial tissue is so tightly packed that it does not have any intercellular space in between. The intercellular substance is too present in very small amount.
Explanation:-
Answer: Option D. -> Epidermal derivatives:
D
The epidermalderivatives, or appendages, of the skin include sweat glands, sebaceous glands, and mammary glands, hair, hair follicles, and nails. All areepidermalinvaginations into the dermis.
Explanation:-
Answer: Option D. -> Erythrocytes:
D
The 5 classes of WBCs, or leukocytes, differ in appearance and function. These classes include neutrophils, monocytes, lymphocytes, eosinophils and basophils. And so erythrocytes are red blood corpuscles (RBCs), while monocytes, lymphocytes and neutrophils are white blood corpuscles (WBCs).
Explanation:-
Answer: Option B. -> Osteoclasts:
B
Osteoclasts are large cells that dissolve the bone. They come from the bone marrow and are related to white blood cells. They are formed from two or more cells that fuse together, so the osteoclasts usually have more than one nucleus. They are found on the surface of the bone mineral next to the dissolving bone.