Arihant NEET Biology 34 Yrs PYQs1 PDF

# 34 Years' (1988-2021) Chapterwise Topicwise NEET Solved Papers - Biology ## Class 11th ### Unit I. Diversity in Living World - What is living? - Biodiversity - Need for classification, Three domains of life, Taxonomy and Systematics, Concept of specie and taxonomic hierarchy, Taxonomical aids -...

# 34 Years' (1988-2021) Chapterwise Topicwise NEET Solved Papers - Biology ## Class 11th ### Unit I. Diversity in Living World - What is living? - Biodiversity - Need for classification, Three domains of life, Taxonomy and Systematics, Concept of specie and taxonomic hierarchy, Taxonomical aids - herbarium, botanical gardens, museums, zoological parks, keys. - Kingdom classification: salient features and classification of Monera, Protista and Fungi into major groups; Lichens; Viruses and Viroids. - Plant Kingdom: Salient features and classification of plants into major groups- Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three to five salient distinguishing features and at least two examples of each category); Angiosperms - classification up to class, characteristic features and examples of salient features of a few families - Fabaceae, Solanaceae, Liliaceae, Asteraceae, Cucurbitaceae, Poaceae, and their economic importance. - Animal Kingdom: Salient features and classification of animals – non-chordate up to phyla level and chordate up to class level (three to five salient features and at least two examples of each category). (no need to remember the classification of orders). ### Unit II. Structural Organisation in Animals and Plants - Structural Organisation in Plants: Tissues - meristematic tissues - types and their characteristics and locations; Permanent tissues - simple tissues parenchyma, collenchyma, sclerenchyma — their structure, location, and functions; Complex tissues - vascular tissues — cambium, xylem – types of xylem elements and their functions, phloem- types of phloem elements and their functions; Tissue systems; Anatomy of dicotyledonous and monocotyledonous roots, stems and leaves (across and vertical sections)— their structure, location, and functions. - Structural Organisation in Animals: Animal tissues - epithelial tissue –types and their characteristics and locations; connective tissue — types and their functions; Muscular tissue – types and their characteristics and locations; Nervous tissue – types and their functions. - Morphology of Flowering Plants: Morphology of flowering plants - root, stem, leaf, inflorescence- racemose and cymose types, flower – parts of a flower, floral diagrams; Pollination - types and agents; Fruits - types. ### Unit III. Cell The Unit of Life - Cell: Cell theory; Cell structure and function; Nucleus, nuclear membrane, nucleolus, cytoplasm, ribosomes, endoplasmic reticulum, golgi bodies, lysosomes, vacuole, mitochondria, plastids, and microbodies; Cell wall – structure and function; Cell cycle — cell division — cell cycle, mitosis, meiosis — their significance. ### Unit IV. Cell Structure and Organisation in Animals - Cell: Cell theory; Cell structure and function; Cell membrane, Cell organelles like Nucleus, nuclear membrane, nucleolus, cytoplasm, ribosomes, endoplasmic reticulum, golgi bodies, lysosomes, vacuole, mitochondria, plastids, and microbodies (elementary idea); Cell wall - structure and function; Cell cycle — cell division — cell cycle, mitosis, meiosis — their significance. ### Unit V. Plant Physiology - Transportation in Plants: Movement of water, gases and nutrients; Cell-to-cell transport-diffusion facilitated diffusion active transport; Plant water relations- Imbibition, water potential, osmosis, transpiration — opening and closing of stomata, factors affecting transpiration; Translocation of organic nutrients- translocation of sugars, amino acids, mineral salts. - Mineral Nutrition: Essential minerals, macro and micronutrients and their role; Deficiency symptoms; Mineral toxicity. - Photosynthesis: Photosynthesis as mean of autotrophic nutrition Site of photosynthesis take place pigments involved in photosynthesis photochemical and biosynthetic phases of photosynthesis cyclic and non-cyclic photophosphorylation, chemiosmostic hypothesis; Factors affecting photosynthesis. - Respiration: Exchange of gases; Cellular respiration - glycolysis, Krebs’ cycle and electron transport system - with special reference to oxidative phosphorylation; Respiratory quotient. - Plant Growth and Development: Growth regulators — auxins, gibberellins, cytokinins, ethylene, abscisic acid, their physiological effects in regulating plant growth and development; Seed germination; Photoperiodism; Vernalisation. ### Unit VI. Human Physiology - Digestion and absorption: Alimentary canal and digestive glands, Role of digestive enzymes and gastrointestinal hormones; Peristalsis, digestion of carbohydrates protein and fats in different parts of gut, absorption of digested product; Calorific value of different foods; Nutritional and digestive disorders — PEM, indigestion, constipation, vomiting, jaundice, diarrhea. - Breathing and Respiration: Respiratory organs in humans - respiratory system; Mechanism of breathing and its regulation in humans — inspiration and expiration; Exchange of gases, transport of gases (CO2 andO2 ) in blood; Respiratory volumes; Disorders related to respiration — asthma, emphysema, occupational respiratory disorders. - Body Fluids and Circulation: Composition of blood, blood groups coagulation of blood; Composition of lymph and its function, Human circulatory system — structure of human heart, heart beat, cardiac cycle, ECG, double circulation; Regulation of cardiac activity, disorders of circularotry system — hypertension, coronary artery disease angina pectoris heart failure, heart attack and heart block. - Excretory products and their elimination: Modes of excretion — ammonotelism, ureotelism, uricotelism; Human excretory system — structure and function of kidney — nephron — its structure and function; Urine formation — ultrafiltration, reabsorption and secretion; Role of ADH and Renin in regulating kidney function; Disorders of excretory system — uraemia, renal failure, renal calculi, nephritis; Dialysis and artificial kidney. - Neural Control and Coordination: Nervous tissue — structure of neuron, nerve impulse — its generation and conduction, synapse; Central Nervous System — brain and spinal cord structure and function; Peripheral Nervous System — different types of nerves and their functions; Reflex arc— types of reflexes — conditioned reflex; Sensory reception; Sensory organs; Sense organs in humans — eye— structure and function of eye, accommodation, and regulation of pupil, defect of eye; Ear— structure and function of ear, mechanism of hearing; Skin— structure and function; Nose; Tongue; Disorders of nervous system — Alzheimer’s disease, Parkinson’s disease, multiple sclerosis. - Chemical Coordination and Integration: Endocrine glands and hormones; Human endocrine system— hypothal- amus, pituitary, pineal, thyroid, parathyroid, adrenal, pancreas, gonads and their secretions; Mechanism of hormone action — hormonal interactions, effects of hormones on target organs; Some important human endocrine disorders — diabetes, thyroid disorders, cushing’s disease, addison’s disease, dwarfism, acromegaly, gigantism, hyperthyroidism, hypothyroidism, goitre. - Reproduction in Organisms: Reproduction, a characteristic feature of all living organisms; Modes of reproduction — sexual and asexual; Sexual reproduction- Flowering plants - flower structure, pollination, fertilisation; Human Reproduction- male and female reproductive systems, menstrual cycle, gametogenesis (spermatogenesis and oogenesis), fertilisation, implantation, pregnancy and parturition; Reproductive health - birth control, contraception and sexually transmitted diseases. ## Class 12th ### Unit I. Genetics and Evolution - Heridity and variation. - Mendelian Inheritance: Deviations from Mendelism - Incomplete dominance, Co-dominance, Multiple alleles and Pleiotropy; Elementary idea of polygenic inheritance; Sex determination - in humans, birds, honeybee; Linkage and crossing over; Sex linked inheritance - Haemophilia, Colour blindness; Mendelian disorders in humans - thalassemia; Chromosomal disorders in humans, down syndrome, turner’s syndrome, Klinefelter syndrome. - Molecular basis of inheritance: Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA packaging; DNA replication (elementary idea); Transcription, genetic code, translation; Gene expression and regulation - Lac operon; Human Genome Project; DNA fingerprinting. - Evolution: Origin of life; Theories and evidence of evolution; Darwin’s contribution; Modern synthetic theory of Evolution; Mechanism of evolution - variation (mutation and recombination) and natural selection with examples, Types of natural selection; Gene flow and genetic drift; Hardy-Weinberg principle; Adaptive radiation; Human evolution. ### Unit II. Biology and Human Welfare - Health and Disease: Pathogens; parasites causing human diseases (malaria, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ringworm); Basic concepts of immunology - vaccines; cancer; HIV and AIDS; Adolescence, drug and alcohol abuse. - Improvement in Food Production: Plant breeding, tissue culture, single cell protein, biofortifications; Apiculture and animal husbandry, Microbes in Human Welfare: In household food processing, industrial production, sewage treatment, energy and alcohol production and as biocontrol agents and biofertilisers. - Biotechnology: Principles and process of biotechnology; Applications of Biotechnology in health and agriculture — genetically modified organisms — Bt crops, transgenic animals, biopesticides, biofertilizers, bioremediation. ### Unit III. Biotechnology and its Applications - Principles and Processes of Biotechnology: Genetically modified organisms — Bt crops, transgenic animals; Biopesticides, biofertilizers, bioremediation. - Applications of Biotechnology in Health and Agriculture: Genetically modified organisms; Bt crops, transgenic animals; Biopesticides, biofertilisers, bioremediation. ### Unit IV. Ecology and Environment - Organisms and Environment: Habitat and niche, Population and ecological adaptations; Population interactions (mutualism, commensalism, parasitism, competition, predation); Population attributes- growth, birth rate and death rate, age distribution. - Ecosystem: Ecosystems- structure and function; Productivity; Decomposition; Energy flow; Pyramids of number, biomass, energy; Nutrient cycling (carbon, phosphorus, nitrogen); Ecological succession; Environmental issues — air pollution and its control; Water pollution and its control; Agrochemicals and their effects; Solid waste management; Radioactive waste management; Biodiversity conservation. ### Unit V. Biodiversity and its Conservation - Biodiversity and its Conservation: Biodiversity- Concept, patterns, importance and loss; Biodiversity conservation; Hotspots, Endangered organisms, extinction; Red Data Book, Biosphere reserves, National parks, Sanctuaries. - Environmental issues: Air Pollution and its control; Water pollution and its control; Agrochemicals and their effects; Solid waste management. ### Unit VI. Biotechnology and its Applications - Principles and Processes of Biotechnology: Genetically modified organisms — Bt crops, transgenic animals; Biopesticides, biofertilisers, bioremediation. - Applications of Biotechnology in Health and Agriculture: Genetically modified organisms; Bt crops, transgenic animals; Biopesticides, biofertilisers, bioremediation ### Unit VII. Ecology and Environment - Organisms and Environment: Habitat and niche, Population and ecological adaptations; Population Interactions (mutualism, commensalism, parasitism, competition, predation) Population Attributes — growth, birth rate and death rate, age distribution. - Ecosystem: Ecosystems — structure and function; Productivity; Decomposition; Energy flow; Pyramids of number, biomass, energy; Nutrient cycling (carbon, phosphorus, nitrogen); Ecological succession; Environmental issues — air pollution and its control; Water pollution and its control; Agrochemicals and their effects; Solid waste management; Radioactive waste management; Biodiversity conservation. ## Class 11th ### Topic 1. The Living World **Diversity and Taxonomy** - Contrasting characteristics generally in a pair used for identification of animals in a taxonomic key are referred to as **couplet**. - Herbariums are a place where dried and pressed plant specimens mounted on sheets are kept. - Catalogues are a booklet containing a list of characters and their alternates useful in identification of various taxa. - Museums are institutes where artistic and educational materials are exhibited to the public. - The label of a herbarium sheet does not contain information about the **height of the plant**. - The definition of biological species was given by **Ernst Mayr**. - In unicellular organisms, reproduction is synonymous with **growth**. **Binomial Nomenclature** - The correctly written scientific name of mango as described by Carolus Linnaeus is **Mangifera indica Linn**. - The rule of ICBN which is **against the rules** is: "Generic and specific name should be written starting with small letters". The first word denoting the genus starts with a capital letter while the specific epithet begins with a small letter. - Nomenclature is governed by certain universal rules. The rule that is contrary to the rules of nomenclature is: "Biological names can be written in any language." ### Topic 2. Biological Classification **Kingdom-Monera** - The **correct** statement about biological organisation is: "Fusion of protoplasm between two motile or non-motile gametes is called plasmogamy". - The size of Pleuropneumonia Like Organism (PPLO) is **0.1μm**. - Oxygen is not produced during photosynthesis by **green sulphur bacteria**. - **Diatoms** are known as chief producers in the oceans and they contribute 40% of marine primary productivity. - Organisms that live in extreme saline conditions are **Archaebacteria**. - Archaebacteria differ from eubacteria in **cell membrane structure**. - The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, are **methanogens**. - **Chromatophores** are pigment-containing membranous extensions in some cyanobacteria. **Kingdom-Protista** - Ciliates differ from all other protozoans in **having two types of nuclei**. - Chrysophytes, euglenoids, dinoflagellates and slime moulds belong to the **Protista** kingdom. - The walls of diatoms are **not easily destructible**. - Diatoms are microscopic and float passively in **water**. - **Protista** have photosynthetic and heterotrophic modes of nutrition. - In Chrysophytes, the cell walls form two thin overlapping shells which fit together. - The common features between Trypanosoma, Noctiluca, Monocystis and Giardia are that they are all **unicellular protists**. ## Class 12th ### Topic 1. Algae - Mannitol as reserve food material is found in **Ectocarpus**. - **Red algae** produce carrageen. - **Red algae** are the major pigment in **red algae**. - **Chlorella and Spirulina** are unicellular algae. - The wrongly matched pair is **Uniflagellate gametes - Polysiphonia**. - **Chlamydomonas** exhibits zygotic meiosis - **Volvox** is an example of colonial algae. ### Topic 2. Bryophytes - Gemmae are present in **liverworts**. - **Sphagnum** is responsible for peat formation. - The feature that is common to multicellular fungi, filamentous algae and protonema of mosses is **multiplication by fragmentation**. - **Marchantia** has archegoniophores. - The male and female gametophytes of **Sphagnum** are independent and free-living. - In the prothallus of a vascular cryptogam, the antherozoids and eggs mature at different times, as a result **self fertilisation is prevented**. - **Elaters** help in spore dispersal in liverworts. - **Peat moss** is used as a packing material because it is **hygroscopic**. - The antherozoids of Funaria are **biflagellated**. ### Topic 3. Pteridophytes - **Funaria** has a completely sporophyte. - **Chara** has upper oogonium and lower round antheridium. - **Chlorella** is an algae that can be employed as food for human beings. - The wrongly matched pair is **oomycetes—female gamete is smaller and motile while male gamete is larger and non-motile**. - Algae have cell walls made up of **cellulose, galactans and mannans**. - **Fucus** stores mannitol. - **Spirogyra** shows advanced feature in sexual reproduction because it shows **physiologically differentiated sex organs**. - **Ulothrix** has chlorophyll-a and c, and fucoxanthin. - **Spirogyra** shows isogamy with non-flagellated gametes. - The plant body of moss is **predominantly gametophyte with sporophyte**. - The unique feature of bryophytes is that they **have sporophyte attached to gametophyte**. - **Bryophytes** lack vascular tissues. - The plant group that produces spores and embryo but lacks vascular tissues and seeds is **Bryophyta**. ### Topic 4. Gymnosperms - **Golden algae** are also called **desmids**. - **Cyanobacteria** are also called **blue-green algae**. - **Phycomycetes** are also called **algal fungi**. - The highest number of species in the world is represented by **fungi**. - **Ustilago** exhibits a haplontic life cycle. - The wrongly matched pair is **Late blight of potato—Alternaria solani**. - **Trichoderma harzianum** is a useful microorganism for **biological control of soil-borne pathogens**. - **Columella** is a specialised structure found in the sporangium of **Rhizopus**. - **Puccinia** forms **uredia and telia** on wheat leaves. - The fungal partner of lichen **provides protection, anchorage and absorption for the alga**. ### Topic 5. Angiosperms - **Cycas and Adiantum** resemble each other in having **motile sperms**. - **Gymnosperms** are called soft wood spermatophytes because they lack **xylem fibres**. - The gametophyte is not an independent, free-living generation in **Pinus**. - Important features distinguishing Gnetum from Cycas and Pinus are **presence of vessel elements and absence of archegonia**. - **Chromatophores** take part in **photosynthesis**. - The ‘walking fern’ is so named because **it propagates vegetatively by its leaf tips**. - **Fern and Funaria** are not seed producers. - In ferns, meiosis occurs when **spores are formed**. - **Ulothrix** filaments produce **isogametes**. - **Brown algae** is characterised by the presence of **fucoxanthin**. - **Chlorella** is an algae very rich in protein. - **Cycas** belongs to **prokaryotes**. - **Spirogyra** is an alga which can fix nitrogen. - The product of conjugation in Spirogyra or fertilisation of Chlamydomonas is a **zygospore**. - The sporophytic generation in **Chlamydomonas** is represented by **zygote**. - In **Chlorophyceae**, sexual reproduction occurs by **isogamy, anisogamy, and oogamy**. - The absence of chlorophyll in the lowermost cell of Ulothrix shows **the beginning of division of labour**. - The chloroplast of Chlamydomonas is **cup-shaped**. - The **globule** is the male reproductive structure of **Chara**. - **Methanogens** are most abundant in a **cattle yard**. - **Archaebacteria** are the oldest living beings. - **Thermococcus, Methanococcus, and Methanobacterium** exemplify **archaebacteria that contain protein homologous to eukaryotic core histones**. - **Xanthomonas** is a species of bacteria that causes bacterial leaf blight of rice. - **Chromosomes** in a bacterial cell can be **1–3 in number** and are **always circular**. - In a bacterial chromosome, the nucleic acid polymers are **circular DNA molecules**. - The **sex factor** in bacteria is **F-replicon**. ### Topic 6. Plant Life Cycle and Alternation of Genertions - Peritrichous flagellation refers to flagella being present **all over the body**. - **Ginkgo biloba** is a living fossil. - **Selaginella** has rhizophores. - **Wolffia** is the smallest flowering plant. - **Macrocystis** is the largest perennial alga. - The life cycle of Ectocarpus and Fucus are **haplodiplontic** and **diplontic**, respectively. - **Metagenesis** refers to **alternation of generations between asexual and sexual phases of an organism**. - **Heterospory** is considered important in the development of seed habit. - In **Paramecium**, the macronucleus controls trophic function, and the micronucleus for reproduction. ### Topic 7. Structural Organisation in Animals - The spongocoel in Poriferans is lined with flagellated cells called **choanocytes**. - The body of a sponge consists of a **meshwork of cells** with **internal cavities lined with food filtering flagellated cells**. - The canal system is a characteristic feature of **sponges**. - The simplest canal system in Porifera is the **ascon** type. - The classification of Porifera is based on **spicules**. - **Sea fan (Gorgonia)** is a living organism that completely lacks a cell wall. - **Cnidaria** includes both marine and freshwater species. - The neurons of **Hydra** are present but the brain is absent. - In **Hydra**, the waste material of food digestion and nitrogenous waste materials are removed from the **mouth and body wall**. - The life cycle of Obelia is best described as **metagenesis**. - The excretory structures of flatworms are **flame cells**. - **Bladderworm/Cysticercus** is the larval stage of **tapeworm**. - The transfer of Taenia to the secondary host occurs as **oncospheres**. ### Topic 8. Phylum-Platyhelminthes - **Round worms (Aschelminthes)** are **pseudocoelomates**. - **Platyhelminthes** are bilaterally symmetrical and acoelomate. - **Planaria** possess a high capacity of **regeneration**. - **Fasciola hepatica** (sheep liver fluke) has a single opening to the outside that serves both as mouth as well as anus. - **Flatworms** are triploblastic. ### Topic 9. Phylum-Annelida - **Metamerism** is common between Ascaris lumbricoides and Anopheles stephensi. - **Rhabditiform** is the larva of Ascaris. - **Ascaris lumbricoides** infection occurs through **contaminated cooked measly pork**. - **Annelids** are bilaterally symmetrical, tripoblastic and metamerically segmented. - The excretory fluids in Annelids regulate the chemical composition of body fluids by removing metabolic waste substances. - In earthworms, **coelomic fluid** acts as a hydraulic skeleton during burrowing. - **Leech** has a ventral central nervous system. - The **chlorocruorin** pigment occurs in **Annelida**. - **Flame cells** in liver fluke are analogous to **nephridia** in an earthworm. ### Topic 10. Phylum-Chordata - In **Archaebacteria**, the cell membrane structure is different from that of Eubacteria. - In bacteria, **plasmids** are **extra-chromosomal material capable of independent replication**. - **Archaebacteria** are the **oldest living beings**. - **Chromatophores** are pigment-containing membranous extensions in some **cyanobacteria**. - **Chromosomes** in a bacterial cell are **circular DNA molecules**. - **Chromatophores** are found in **photosynthetic bacteria** and contain **bacteriochlorophyll**. - The label of a herbarium sheet does not carry information about the **height of the plant**. - The definition of biological species was given by **Ernst Mayr**. - In unicellular organisms, reproduction is synonymous with **growth**. - **Archaebacteria** differ from eubacteria in **cell membrane structure**. - **Methanogens** are the primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, and are **strict anaerobes**. - **Chromatophores** are pigment-containing membranous extensions in some **cyanobacteria**. ### Topic 11. Phylum-Chordata - All chordates possess **an axial skeletal rod of notochord**. - All vertebrates possess a **dorsal hollow central nervous system**. - **Necturus** is a **mud puppy**. - **Typhlos** is a **blind snake**. - In a bacterial chromosome, the nucleic acid polymers are **circular DNA molecules**. - The **sex factor** in bacteria is **F-replicon**. - **Cauliflower mosaic virus** contains **dsDNA**. ### Topic 12. Phylum-Echinodermata - **Metagenesis** is not observed in **helminths**. - **Euryarchaeota** includes **Methanobacterium, Methanococcus, and Thermococcus**. - **Diatomaceous Earth** is formed by the cell walls of **diatoms**. - **Diatoms** are chief producers in the **oceans**. - **Chlorella** is a **unicellular** algae. - In **Protista**, the cell wall is **absent**. - **Nuclear membrane** is **not present** in **Monera**. - **Diatoms** have cell walls that form two thin overlapping shells which fit together like a soap box. ### Topic 13. Phylum-Chordata - In **Chlamydomonas**, the macro-nucleus controls trophic function, and the micro-nuclei for reproduction. - The presence of **gills** in the tadpole of frog indicates that the frog evolved from **gilled ancestors**. - **Nostoc** lacks a nuclear membrane. - **Nuclear membrane** is **absent** in **prokaryotes**. - **Chromosomes** in a bacterial cell are **circular DNA molecules**. - **Chromatophores** are found in **photosynthetic bacteria**. ### Topic 14. Phylum-Arthropoda - The family **Muscidae** includes the **housefly**. - In **bacteria**, **plasmids** are **extra-chromosomal material capable of independent replication**. - **Archaebacteria** are the **oldest living beings**. - **Chromatophores** are pigment-containing membranous extensions in some **cyanobacteria**. - **Chromatophores** are found in **photosynthetic bacteria**, and contain **bacteriochlorophyll**. - The label of a herbarium sheet does not carry information about the **height of the plant**. - The definition of biological species was given by **Ernst Mayr**. - In unicellular organisms, reproduction is synonymous with **growth**. - **Archaebacteria** differ from eubacteria in **cell membrane structure**. - The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, are **strict anaerobes**. - **Chromatophores** are pigment-containing membranous extensions in some **cyanobacteria**. - **Chromosomes** in a bacterial cell are **circular DNA molecules**. - In **bacteria, plasmids** are **extra-chromosomal material capable of independent replication**. - **Archaebacteria** are the **oldest living beings**. - **Chromatophores** are pigment-containing membranous extensions in some **cyanobacteria**. ### Topic 15. Plant Growth and Development - **2, 4-D** is a plant hormone used to destroy weeds in a field. - **Auxin** is a plant hormone that stimulates nodule formation and is used to increase dwarf shoots. - **IAA and IBA** are used to induce parthenocarphy. - **Plant plasticity** refers to the ability to modify itself by forming different kinds of structures to adapt and cope with changes in its environment. - **Effect of auxins** is removed and growth of lateral buds is enhanced when the **shoot tip is removed**. - **Gibberellins** are used to increase the yield of **sugarcane**. - **Auxin and ethylene** can be applied to artificially induce flowering in pineapple plants throughout the year. - **Auxin** can prevent fruit and leaf drop at early stages. - **Avena curvature** is a bioassay of **auxin**. - **Auxin and cytokinin** can be added to a medium to secure shoots as well as roots. - **Auxin** can be bioassayed by **Avena coleoptile curvature**. ### Topic 16. Digestion and Absorption - The sphincter of Oddi is present at the **junction of hepato-pancreatic duct and duodenum**. - **Ileum** is a highly coiled part of the alimentary canal. - **Vermiform appendix** arises from the **caecum**. - The **ileum** opens into the **large intestine**. - The **Crypts of Lieberkuhn** are simple tubular intestinal glands which occur throughout the small intestine between the villi. - **Glisson’s capsule** is a thin layer of connective tissue in the **liver**. - **Islets of Langerhans** constitute the endocrine part of **pancreas**. - **Brunner’s glands** are located in the submucosa of the **duodenum**. - **Thecodont, Diphyodont, Heterodont** describe human dentition. - The **conversion of milk to curd** improves its nutritional value because it increases the amount of **vitamin-B12**. - **Premolars** are absent in a child with twenty teeth. - The cells of the **crypts of Lieberkuhn** that secrete antibacterial lysozyme are **Paneth cells**. - The **hepatic portal vein** drains blood to the liver from the **intestine**. - **Sphincter of Oddi** guards the opening of the **hepatopancreatic duct** into the duodenum.. - **Succus antericus** refers to **intestinal juice**. - **Oxyntic cells** secrete intrinsic factor that helps in the absorption of **vitamin-B12**. - The proteolytic enzyme **rennin** is found in **gastric juice**. - The enzyme **enterokinase** helps in the conversion of **trypsinogen into trypsin**. - **Rennin** acts on **milk proteins**. - **Mature proglottids** contain both male and female organs. - **The excretory structures** of flatworms/Taenia are **flame cells**. - **Bladderworm/cysticercus** is the larval stage of **tapeworm**. ### Topic 17. Breathing and Exchange of Gases - **Alveoli** are thin walled vascular bag-like structures for exchange of gases - **The brain** in human body is most affected due to shortage of oxygen. - **Alveolar epithelium and capillary endothelium** separate the air at the site of gas exchange from the blood in the alveoli of the lungs. - Respiration in humans occurs by **breathing**. - The simplest type of canal system in Porifera is the **ascon** type. - The classification of Porifera is based on **spicules**. - The classification of sponges is primarily based on **spicules**. ### Topic 18. Body Fluids and Circulation - Blood group AB is called as "universal recipient" because they have **no antibodies in the plasma**. - Blood group 'O' is considered the universal donor because **they have no antigens on RBCs**. - **Thrombin** converts inactive fibrinogens to fibrins. - **Choanocytes** are not found in **leech, dolphin, and pengiun**. - **All of the above** are correct. - The canal system is a characteristic feature of **sponges**. - **All of the following** are correct. - **Choanocytes** are not found in **leech, dolphin, and pengiun**. - **All of the following** are correct. ### Topic 19. Excretory Products and Their Elimination - **Podocytes** form filtration slits in the Bowman’s capsule of the nephrons. - Uricotelic mode of passing out nitrogenous wastes is found in **reptiles and birds**. - In **earthworms**, the enteronephric nephridia are mainly concerned with **excretion of nitrogenous wastes**. - The chief nitrogenous component excreted in **cockroach** is **uric acid**. - **Turtles** and **alligators** are ureotelic animals. - **Ornithine cycle** is involved for the conversion of ammonia into urea. - **Uricotelism** is found in **birds, reptiles and insects**. - In mammals, **urea** is the principal nitrogenous excretory compound. - **The loop of Henle** is involved in the reabsorption of water. - The kidney of an adult frog is a **mesonephros**. - **Birds and lizards** excrete uric acid as the chief nitrogenous waste. - The **proximal convoluted tubule** is the main site of reabsorption of useful substances. - The **brush border** is characteristic of the **proximal convoluted tubule**. - The **afferent arteriole** carries blood away from the glomerulus towards the renal vein. - **Podocytes** create filtration slits (slit pores) for the filtration of blood into the Bowman’s capsule. ### Topic 20. Locomotion and Movement - **H-zone** in skeletal muscle fibre disappears during muscle contraction. - **Calcium ions** are responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction. - **Sustained muscle contraction** due to repeated stimuli is known as **tetanus**. - The contractile protein of skeletal muscle involving ATPase activity is **myosin**. - The functional unit of the contractile system in striated muscle is **sarcomere**. - **Hyaline cartilage** is present at the ends of long bones. - **Intercostal muscles** are located in the **ribs**. ### Topic 21. Neural Control and Coordination - Receptor sites for neurotransmitters are present on the **post-synaptic membrane**. - **Schwann cells and oligodendrocytes** produce the myelin sheath. - Destruction of the anterior horn cells of the spinal cord would result in loss of **voluntary motor impulses**. - **Parasymathetic neural signals** affect the working of the heart by **reducing both heart rate and cardiac output**. - The axonal membrane is **more permeable to K+ ions and nearly impermeable to Na+ ions** when a neuron is in the resting state. - The movement of **K+ ions from intracellular fluid to extracellular fluid** results in the action potential during nerve impulse transmission. - **Nodes of Ranvier** are gaps in the **myelin sheath**. - **Neuron** is regarded as the unit of nervous tissue. - **The synapse** is the junction between the axon of one neuron and the dendrite of the next. - **Sympathetic nervous system** induces **heartbeat**. - **Visceral organs** are innervated by **both sympathetic and parasympathetic nerves** but are **not under conscious control**. - **Afferent nerve fibers** carry impulses **from receptors to CNS**. - The function of the parasympathetic nervous system is **constriction of pupil**. - **Hypothalamus** is the thermoregulatory centre in the brain and maintains the body temperature. - **Neuromuscular junction** is the site of stimulation of a muscle fibre by a motor neuron. - Injury localised to the hypothalamus would most likely disrupt **regulation of body temperature**. - **Third ventricle of brain** is also known as **diacoel**. - **Vagus nerve** is the **Xth cranial nerve**. - **The respiratory centre** is situated in the **medulla oblongata**. - **The Nissl’s granules** of a nerve cell are made up of **ribosomes**. - The roof of the cranium of a frog is formed by **the frontoparietal**. - In mammals, **the sympathetic nerves** arise from the **thoraco-lumbar spinal segments**. ### Topic 22. Chemical Coordination - **Oxytocin and vasopressin** are hormones stored and released from the **neurohypophysis**. - **GnRH** acts on the **anterior pituitary gland**. - **Hypersecretion of growth hormone** in adults does not cause further increase in height because **epiphyseal plates close after adolescence**. - The amino acid, **tryptophan**, is the precursor for synthesis of **melatonin and serotonin**. - **Insulin and glucagon** are not antagonistic, but are **antagonistic** to each other. - **Parathormone** leads to **increased calcium levels** in the blood. - **Insulin** is a hormone secreted by the **beta cells of islets of Langerhans**. - **Iodine-131** is used in the detection of **thyroid