NARAYANKAR NOTES

  Each kidney is covered by three layers . The outermost layer is renal fascia , made of thin fibrous tissue, and it fixes the kidney to the abdominal wall. The middle layer is the adipose capsule , which is fat tissue that protects the kidney from shock. The innermost layer is the renal capsule , a smooth membrane that protects the kidney from infections and continues with the ureter . Inside the kidney, there are two main regions . The outer region is the renal cortex , which is red and granular. It contains Malpighian bodies (filtering units), convoluted tubules (twisted tubes), and blood vessels . The inner region is the renal medulla , which is pale red and looks striped. It contains Loops of Henle and collecting ducts . These structures form cone-shaped parts called renal pyramids . The cortex extends between pyramids as renal columns ( Columns of Bertini ) . The narrow tip of each pyramid is called the renal papilla . There are many renal pyramids in the kidney. The tip o...

  Respiration and Energy Transfer Biology Respiration and Energy Production – Grade 7 13.1 Formation of ATP ATP (Adenosine Triphosphate) is the energy currency of the cell. The formation of ATP is called phosphorylation . In nature, phosphorylation occurs in three different ways: Photophosphorylation – occurs during photosynthesis. Substrate-level phosphorylation Oxidative phosphorylation Substrate-level phosphorylation is the direct transfer of a phosphate group from a substrate to ADP to form ATP. It occurs in the cytoplasm and in the mitochondrial matrix. Oxidative phosphorylation occurs on the inner mitochondrial membrane. Here, ATP is formed using the energy released during oxidation of NADH+H + and FADH 2 . When energy is required, ATP is broken down (hydrolysed) into ADP and inorganic phosphate, releasing energy for metabolic activities. Respiration is a catabolic process in which complex organic compounds are broken down to release en...

  Plant Tissues and Anatomy Anatomy is the study of the internal structure of an organism. Plants are made of organs like root, stem, and leaf. Each organ is made of groups of cells. A group of similar or different cells having a common function and origin is called a tissue . Plant tissues are divided into two main types: Meristematic tissue Permanent tissue 8.2 Meristematic Tissue Meristematic tissue is a group of young, living cells that have the ability to divide. These tissues are found in growing regions of the plant. Cells are small and actively dividing Cells are polygonal or round in shape No intercellular spaces are present Cell wall is thin and made of cellulose Nucleus is large and prominent Vacuoles are very small or absent Cells have high metabolic activity Cells are immature Classification of Meristem: 1. Based on Origin Promeristem (Primordial meristem) – found at root and shoot tips in embr...

  Cell Cycle and Cell Division – Grade 7 Biology Cell Cycle and Cell Division – Grade 7 Life of all multicellular organisms starts from a single cell called a zygote . A zygote is formed after fertilization when male and female gametes fuse. From this single cell, the whole body of an organism develops. Growth of every living organism depends on cell division . New cells are formed when old cells divide. According to cell theory, every new cell arises from a pre-existing cell. 7.1 Cell Cycle The sequence of events that occurs in the life of a cell from one division to the next is called the cell cycle . The cell cycle has two main phases: Interphase – preparation phase M-phase – division phase Interphase Interphase is the stage between two successive cell divisions. It is the longest phase of the cell cycle. During this phase, the cell is very active and prepares itself for division. Interphase is divided into three sub-phases: ...

  Human Nutrition & Digestion What is Nutrition? Nutrition is the sum of all processes by which an organism (like a human) consumes and uses food. According to the World Health Organization (WHO) , it is the intake of food in relation to what your body needs. To be healthy, our body needs specific items in the right amounts: Carbohydrates, Proteins, Fats, Vitamins, Minerals, Water, and Fibers. The 5 Steps of the Digestive Process  Nutrition isn't just eating; it involves these five technical stages: Ingestion: Putting food into the mouth. Digestion: Breaking complex, large food into small, simple pieces. Absorption: The blood picking up the nutrients. Assimilation: The body cells using those nutrients for energy and growth. Egestion: Removing the undigested waste from the body . ...

Assertive (or declarative) sentences state facts, Interrogative sentences ask questions, Imperative sentences give commands or requests, and Exclamatory sentences express strong emotion or surprise.  Here are one-word definitions for each type: Assertive: Statement Interrogative: Question Imperative: Command Exclamatory: Exclamation   

  Physics MCQs 📘 CHAPTER 1: SOUND MCQs 1. Sound waves in air are A. Transverse waves B. Longitudinal waves C. Electromagnetic waves D. Standing waves ✔ Answer: B 2. The speed of sound depends mainly on A. Amplitude B. Frequency C. Density and elasticity of medium D. Loudness ✔ Answer: C 3. Unit of frequency is A. m/s B. rad/s C. Hertz D. Decibel ✔ Answer: C 4. Which property remains unchanged when sound passes from one medium to another? A. Velocity B. Wavelength C. Frequency D. Amplitude ✔ Answer: C 5. Laplace’s correction is applied because sound propagation is A. Isothermal B. Adiabatic C. Isochoric D. Isobaric ✔ Answer: B 6. Speed of sound is maximum in ...