Students can go through AP Inter 1st Year Botany Notes 9th Lesson Cell: The Unit of Life will help students in revising the entire concepts quickly.
AP Inter 1st Year Botany Notes 9th Lesson Cell: The Unit of Life
→ Unicellular Organisms are capable of independent Existence and performing the essential functions of life.
→ Anton von Leeuwenhoek first saw and described a live cell. .
→ Schleiden and Schwann together formulated cell theory.
→ R.Virchow, defined cell theory as, All living organisms are composed of cells and products of cells. All cells arise from pre-existing cells.
→ Mycoplasmas, the smallest cells are only 0.3 /μm in length.
→ The largest Isolated single cell is the egg of an ostrich.
→ The Prokaryotic cells are represented by bacteria, blue-green algae, mycoplasma and PPLO.
→ The four basic shapes of Bacteria are coccus (spherical) Bacillus (rod shaped) Vibrio (comma) and spirillum (spiral).
→ There is no well defined nucleus in Prokaryotic cell.
→ The genetic material is maked, not enveloped by nuclear membrane and is called nucleoid.
→ In Prokaryotic cells, In addition to genomic DNA, a small circular DNA is present called plasmids. ‘
→ Bacterial flagellum is composed of three parts namely filament, hook and basal body.
→ Pili and Fimbriae are surface structures of the Bacteria but do not play a role in motility.
→ 70s type of Ribosomes are present in. Prokaryotic cell.
→ Reserve food materials are in the form of phosphate granules, Cyanophycean granules and Glycogen granules.
→ Eukaryotic cells have a well defined nucleus.
→ Cell wall i a non-living rigid structure and forms an outer covering for the plasma membrane of fungi and plants.
→ Cell wall is made up of cellulose, hemicellulose, pectins and proteins.
→ Endoplasmic Reticulum, golgi complex, lysosomes and vacuoles together called endomembrane system.
→ The Endoplasmic reticulum with ribosomes is called Rough ER and without ribosomes is called smooth ER.
→ Cell organelle which involves in the synthesis of cell wall materials is golgi complex.
→ Cell organelles Causes autolysis of cells are lysosomes.
→ Vacuoles play an Important role in osmoregulation.
→ Mitochondria are the sites of aerobic respiration.
→ Leucoplasts which store Carbohydrates are called Amyloplasts which store proteins are called aleuroplasts and which store fats are called Elaioplasts.
→ Chloroplasts are the organelles involved in photosynthesis.
→ 80 s type of ribosomes are present in Eukaryotic cells.
→ The centrioles forms spindle fibres during cell division.
→ Nucleus, dynamic centre of the cell or Master Cell organelle controls all metabolic activities of the cell.
→ Chromatic contains DNA and some basic proteins called Histones.
→ Peroxysomes and Glyoxisomes are called Microbodies.
→ Active transport : Transmembrane transport requiring energy mostly as ATP.
→ Antibiotics : Antimicrobial substances produced by some microbes.
→ Axoneme : The core part of a cilium or flagellum that consists of microtubules in a typical 9 + 2 array.
→ Carotenoids : Terpenoid pigments abundant in chromoplasts that impart yellow, orange or red colour.
→ Chromatin : Thread like coloured material of the eukaryotic nucleus.
→ Cytoskeleton : Elaborate network of filamentous proteinaceous structures found in the cytoplasm of eukaryotic cells.
→ Glycocalyx : A layer outside bacterial cell wall usually made of polysaccharides.
→ Histones : Basic proteins associated with DNA.
→ Kinetochore : Disc shaped structures located in the centromeric part of the chromosome.
→ Mesosome : Membrane infolding in some bacteria that helps in cell wall formation and DNA- replication.
→ Passive transport : Transmembrane transport not requiring energy i.e., Movement down the concentration gradient.
→ Plasmids: Small circular DNA found outside genomic DNA in many bacteria.
→ Satellite : A round terminal part of the chromosome present beyond the secondary constriction in some chromosomes.
→ Endomembrane System : A group of cell organelles with coordinated functions (ER, Golgi, lysosomes and vacuoles).
→ Thylakoids : Flattened membranous sacs present inside chloroplasts.
→ Cell is the basic unit of life and structural, functional unit of an organism.
→ All living organisms are made of cells or aggregates of cells.
→ Cells vary in shape, size and functions.
→ Cell theory was proposed by Schleiden and Schwann and later by Rudolf Virchow.
→ Cell theory; (i) All living organisms are composed of cells and their products.
(ii) New cells arise from pre-existing cells.
→ Types of cells: (i) Prokaryotic cells (ii) Eukaryote cells
→ Vacuoles play an important role in osmo regulation 0f plant cells. [IPE]
→ Meta centric chromosome has middle centromere forming two equal arms of the chromosome.
→ The satellite chromosome contains a small segment called satellite which is separated from the main body of the chromosome by a secondary constriction.
→ Middle lamella js a layer made up of calcium pectate. It holds the neighbouring cells together.
→ The cell organelles which contain chlorophyll pigment are called chloroplasts. [IPE]
→ Mitochondria are the power houses of cell. [IPE]
→ Structure of Nucleus consists of four main parts:
- Nuclear envelope
- Nuclear matrix
- Chromatin material
- Nucleolus
→ Types of chromosomes (based on the position of centromere):
- Metacentric
- Sub metacentric
- Acrocentric
- Telocentric
→ Nucleosome is a structural unit of eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones. [IPE]
→ A cell organelle containing hydrolytic enzymes is lysosome. [NEET-2017]
→ Lysosomes cell organelles is enclosed by a single membrane. [NEET-20I6]
→ Microtubules are the constituents of spindle fibres, centrioles and cilia. [NEET-2016]
→ Cellular organelles with membranes are lysosomes, Golgi apparatus, mitochondria. [2015]
→ The chromosomes in which centromere is situated close to one end are acrocentric. [NEET-2015]
→ The structures that are formed by stacking of organised flattened membranous sacs in the chloroplasts are grana. [NEET-2015]
→ Nuclear envelope is a derivative of rough endoplasmic reticulum. [NEET-2015]
→ DNA is not present in ribosomes. [NEET-2015]
→ The motile bacteria are able to move by flagella. [NEET-2015]
→ ”The concept of “Omnis Cellula -e-Cellula” regarding cell division was proposed by Rudolf Virchow. [NEET-2019]
→ The shorter and longer arms of a submetacentric chromosome are referredto as p-arm and q-arm respectively. [NEET-2019]
→ Pair of organelles which do not contain DNA are Lysosomes and Vacuoles. [NEET-2019]
→ In metacentric chromosome, the centromere is situated in the middle of two equal arms of chromosomes. [NEET-2021]