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 Ribosomes CBSE Class 11: MCQs, Case Study & Assertion Reason Questions  Structure and function of ribosomes showing 70S and 80S subunits involved in protein synthesis.   - Dr.Sanjaykumar Pawar  Ribosomes  1. What are Ribosomes? Ribosomes are tiny granular (grain-like) structures present inside cells. They were first observed under an electron microscope. They were discovered by in 1953 . Under the electron microscope, they appear as dense particles. 2. Composition of Ribosomes Ribosomes are made up of: Ribosomal RNA (rRNA) Proteins Therefore, ribosomes are ribonucleoprotein particles . 3. Membrane Around Ribosomes Ribosomes are not surrounded by any membrane . Hence, they are called non-membranous cell organelles . 4. Function of Ribosomes Ribosomes are the site of protein synthesis . They help in translating genetic information into proteins. Therefore, ribosomes are known as the "Protein Factories of the Cell." Types of Ribos...

NCERT Class 11 Biology – Chapter-wise Index (Full Contents Format) CONTENTS A NOTES FOR THE TEACHERS AND STUDENTS  NCERT Class 11 Biology complete chapter-wise structure organized into units for easy revision and exam preparation. Dr.Sanjaykumar Pawar  UNIT I: DIVERSITY IN THE LIVING WORLD (Pages 1–54) Chapter 1: The Living World (Page 10) 1.1 Diversity in the Living World 1.2 Taxonomic Categories Species Genus Family Order Class Phylum / Division Kingdom 1.3 Taxonomical Aids Herbarium Botanical Gardens Museums Zoological Parks Key Summary & Exercises Chapter 2: Biological Classification (Page 23) 2.1 Kingdom Monera 2.2 Kingdom Protista 2.3 Kingdom Fungi Phycomycetes Ascomycetes Basidiomycetes Deuteromycetes 2.4 Kingdom Plantae 2.5 Kingdom Animalia 2.6 Viruses, Viroids and Lichens Summary & Exercises Chapter 3: Plant Kingdom (Page 37) 3.1 Algae Chlorophyceae Phaeophyceae Rhodophyceae 3.2 Bryophytes 3.3 Pteridophytes 3.4 Gymnosperms 3.5 An...

Why are Living Organisms Classified? Hierarchical classification of living organisms explained through a clear taxonomy tree diagram. - Dr.Sanjaykumar Pawar  Answer: Biological classification is the scientific arrangement of organisms into a hierarchical system of groups and subgroups based on their similarities, differences, and evolutionary relationships. Need for Classification 1. To Facilitate Identification Millions of organisms exist on Earth. Classification provides a systematic framework for the easy and accurate identification of known as well as newly discovered organisms. 2. To Simplify Study of Organisms It is not possible to study each organism individually. Grouping organisms with similar characteristics makes their study convenient and systematic . Knowledge of one organism helps in understanding other members of the same group. 3. To Understand Evolutionary Relationships (Phylogeny) Classification reveals the evolutionary history of organisms. ...

  Endocrine System Summary Notes (NEET Biology – Easy Line by Line Explanation)  - Dr.Sanjaykumar pawar 1. Hormones and Their Functions Hormones are special chemical messengers produced by endocrine glands. They help in: Coordination of body activities Regulation of body functions Integration between organs Hormones control: Metabolism Growth Development Reproduction Homeostasis 2. Endocrine System Organs The human endocrine system includes: Hypothalamus Pituitary gland Pineal gland Thyroid gland Adrenal gland Pancreas Parathyroid gland Thymus Gonads: Testis (male) Ovary (female) Other organs also producing hormones: Gastrointestinal tract Kidney Heart 3. Pituitary Gland (Master Gland) Divisions of Pituitary The pituitary gland has 3 parts: (i) Pars distalis (Anterior pituitary) Produces 6 trophic hormones. Trophic hormones regulate other endocrine glands. (ii) Pars intermedia Secretes only one hormone: MSH (Melanocyte Sti...

  19.2.9 Testis — Easy NEET Notes  - Dr.Sanjaykumar pawar Location of Testis Testes are present in the scrotal sac . The scrotal sac lies outside the abdomen in males. Lower temperature in the scrotum helps in sperm formation . Important Point Testis acts as: Primary sex organ → produces sperm Endocrine gland → secretes hormones Structure of Testis 1. Seminiferous Tubules Coiled tube-like structures inside testis. Main site of spermatogenesis (formation of sperms). 2. Stromal / Interstitial Tissue Tissue present between seminiferous tubules. Contains Leydig cells . Leydig Cells (Interstitial Cells) Found in intertubular spaces. Produce male sex hormones called androgens . Main androgen = Testosterone . NEET Fact LH hormone from pituitary stimulates Leydig cells to produce testosterone. Functions of Androgens (Testosterone) 1. Development of Male Reproductive Organs Androgens help in growth and maturation of: Epididymis Vas defere...

  Forebrain, Midbrain and Hindbrain – Easy NEET Notes 18.4.1 Forebrain Forebrain consists of: Cerebrum Thalamus Hypothalamus These are the major parts of the forebrain. Cerebrum Cerebrum is the largest part of the human brain . It controls: Thinking Intelligence Memory Learning Speech Voluntary actions Cerebral Hemispheres A deep groove divides the cerebrum into: Left cerebral hemisphere Right cerebral hemisphere Corpus Callosum Both hemispheres are connected by nerve fibres called: Corpus callosum It allows communication between the two hemispheres. Cerebral Cortex Outer layer of cerebrum is called the cerebral cortex . It is highly folded to increase surface area. It appears grey due to presence of neuron cell bodies. Therefore, it is called Grey Matter . Functions of Cerebral Cortex It contains: Motor areas → control voluntary movements. Sensory areas → receive sensory impulses. Association areas → involved in: Memory Inte...