General Q&A for Class 12 · Page 92
5,215 free answers in General for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What tissue is stored in the human body?
When tissue is damaged, the body initiates a complex healing response involving inflammation, cell proliferation, and tissue remodeling. This process aims to restore structure and function, though outcomes vary depending on tissue type and damage severity. The healing process begins immediately with hemostasis (blood clotting) to stop bleeding from damaged blood vessels. Platelets aggregate at the injury site, forming a clot that prevents blood loss and creates a temporary barrier. Wi
- GeneralClass 12All
Why is tissue needed?
Tissue is needed because it enables the cellular specialization and organization essential for complex multicellular life. Without tissue-level organization, organisms would be limited to single-celled or simple multicellular forms incapable of sophisticated functions. Tissues provide critical capabilities through division of labor. Individual cells have limited size and functional range, but when similar cells organize into tissues, they perform specialized roles with far greater eff
- GeneralClass 12All
What happens when tissue is damaged?
When tissue is damaged, the body initiates a complex healing response involving inflammation, cell proliferation, and tissue remodeling. This process aims to restore structure and function, though outcomes vary depending on tissue type and damage severity. The healing process begins immediately with hemostasis (blood clotting) to stop bleeding from damaged blood vessels. Platelets aggregate at the injury site, forming a clot that prevents blood loss and creates a temporary barrier. Wi
- GeneralClass 12All
What are tissue 2 marks?
"Tissue 2 marks" likely refers to a short-answer exam question worth 2 marks asking for a brief definition or description of tissue. Such questions typically require concise, accurate responses covering essential concepts without extensive detail. An appropriate 2-mark answer would be: "Tissue is a group of similar cells and their intercellular matrix that work together to perform specific functions in organisms. The four main animal tissue types are epithelial, connective, muscle, an
- GeneralClass 12All
What is 90% of the human body made of?
Approximately 90% of the human body's atoms are hydrogen, though by mass, the body is roughly 60% water, with the remaining composition including proteins, fats, minerals, and carbohydrates. The answer varies depending on whether measuring by atom count, mass, or cellular composition. By atom count, approximately 60% are hydrogen atoms and 26% are oxygen atoms (together comprising over 85%), with carbon accounting for about 11%, and nitrogen, calcium, phosphorus and other elements mak
- GeneralClass 12All
Which is the best tissue to use?
The "best" tissue to use depends entirely on the intended purpose, as each tissue type has evolved specific characteristics making it optimal for particular functions. No single tissue type is universally superior. For protective barriers, epithelial tissue excels through its tightly packed cells forming continuous sheets that guard against pathogens, physical damage, and water loss—this makes stratified squamous epithelium ideal for skin. For structural support, bone (a connect
- GeneralClass 12All
Which is the largest tissue in the body?
The largest tissue in the body is connective tissue, which comprises approximately 45-50% of total body mass and exists throughout virtually every body region. However, if asking about a specific tissue structure, the skin (composed primarily of epithelial and connective tissues) represents the largest organ. Connective tissue's abundance reflects its diversity and ubiquity. It includes bone (providing skeletal framework), cartilage (cushioning joints), adipose tissue (storing energy)
- GeneralClass 12All
What is the origin of tissue?
The origin of tissue traces to evolutionary developments enabling multicellular organization and to developmental processes forming tissues within individual organisms. Both evolutionary and developmental origins involve cells specializing and organizing for improved efficiency. Evolutionarily, tissues originated over 600 million years ago when single-celled organisms developed multicellular cooperation. Early multicellular organisms initially consisted of similar cells, but evolution
- GeneralClass 12All
Who named the tissue?
Marie François Xavier Bichat, a French anatomist and pathologist, coined the term "tissue" (from the French "tissu," meaning "woven") in the late 1700s. His choice reflected the woven, fabric-like appearance of body structures he observed during anatomical dissections. Bichat's linguistic choice proved remarkably apt—like fabric woven from threads, tissues are composed of individual cells organized into functional structures. Working before microscopy revealed cellular de
- GeneralClass 12All
Are there 78 or 79 organs?
The question of whether there are 78 or 79 organs stems from recent debate over whether the mesentery (tissue connecting the intestine to the abdominal wall) qualifies as a distinct organ. However, organ counts vary depending on classification criteria, and there's no universally agreed number. The mesentery controversy arose when researchers proposed in 2017 that this connective tissue structure should be classified as an organ due to its continuous structure and distinct functions b
- GeneralClass 12All
What is a cell type?
A cell type refers to a distinct category of cells with specific structures, functions, and characteristics. The human body contains over 200 different cell types, each specialized for particular roles that contribute to overall organism function. Cell types are classified based on multiple criteria including structure, function, location, and developmental origin. Major categories include epithelial cells (forming protective barriers and linings), connective tissue cells (providing s
- GeneralClass 12All
What is a living cell?
A living cell is the smallest unit of life capable of performing all processes necessary for survival, including metabolism, growth, reproduction, response to stimuli, and maintaining internal equilibrium (homeostasis). Cells represent life's fundamental organizational unit. Living cells possess several defining characteristics distinguishing them from non-living matter. They maintain organized internal structures enclosed by membranes that regulate what enters and exits. They extract
- GeneralClass 12All
What tissues can be attacked by your immune system?
Your immune system can potentially attack virtually any tissue in the body during autoimmune conditions, though certain tissues are more commonly targeted. Autoimmune diseases demonstrate the immune system's capacity to mistakenly identify self-tissues as threats. Commonly attacked tissues include joints (rheumatoid arthritis), pancreatic insulin-producing cells (type 1 diabetes), thyroid tissue (Graves' disease, Hashimoto's thyroiditis), nervous tissue myelin coating (multiple sclero
- GeneralClass 12All
What is the blood test for connective tissue disease?
The blood test for connective tissue disease typically involves an Antinuclear Antibody (ANA) test, which screens for autoantibodies commonly present in various connective tissue disorders. However, comprehensive evaluation usually requires multiple specialized tests. The ANA test detects antibodies that target components within cell nuclei—a positive result suggests possible autoimmune activity but requires further testing for specific diagnosis. Follow-up tests identify partic
- GeneralClass 12All
What is a tissue disorder?
A tissue disorder is any condition affecting tissue structure or function, leading to impaired health. These disorders range from localized injuries to systemic diseases affecting multiple tissue types throughout the body. Tissue disorders are classified in various ways. Inflammatory tissue disorders involve excessive or inappropriate immune responses causing tissue swelling, pain, and damage examples include arthritis (joint tissue inflammation), tendinitis (tendon inflammation), and
- GeneralClass 12All
What is the strongest tissue in the body?
The strongest tissue in the body is tooth enamel, the hard outer covering of teeth, which is even harder than bone. However, if considering tensile strength rather than hardness, tendon (a type of connective tissue) demonstrates exceptional resistance to stretching forces. Tooth enamel consists of approximately 96% hydroxyapatite (a crystalline calcium phosphate), making it the hardest substance in the human body. This extraordinary hardness protects teeth during chewing forces that c
- GeneralClass 12All
Where is tissue made?
Tissue is made through cellular division and differentiation processes that occur throughout the body in specific locations depending on the tissue type. New tissue formation happens during embryonic development, childhood growth, and ongoing adult tissue renewal and repair. During embryonic development, all tissues originate from three primary germ layers: ectoderm (forming nervous tissue and skin epithelium), mesoderm (producing muscle, connective tissues, and some epithelial lining
- GeneralClass 12All
Why are tissues important?
Tissues are important because they enable complex multicellular organisms to function efficiently through cellular specialization and division of labor. This organizational level makes possible the sophisticated capabilities distinguishing complex life forms from simple organisms. Tissues provide several critical advantages. Specialization allows specific cell groups to become highly efficient at particular tasks rather than every cell performing all functions poorly. Muscle tissue ex
- GeneralClass 12All
What is plant tissue?
Plant tissue is organized groups of plant cells working together to perform specific functions necessary for plant growth, development, and survival. Plant tissues are classified as either meristematic (capable of continuous cell division) or permanent (differentiated cells with specialized functions). Meristematic tissues contain undifferentiated cells that actively divide to produce new cells, enabling plant growth. Apical meristems at root and shoot tips facilitate lengthwise growt
- GeneralClass 12All
What diseases affect tissues?
Numerous diseases affect tissues, ranging from inflammatory conditions and degenerative disorders to cancers and infections. Virtually every medical condition involves tissue-level changes, though some specifically target particular tissue types. Epithelial tissue diseases include cancers (lung, skin, breast, colorectal carcinomas), inflammatory conditions (dermatitis, gastritis), and functional disorders (irritable bowel syndrome affecting intestinal epithelium). Connective tissue di