GEN BIO Q1 PDF - Cell Theory

Lesson 1: Cell Theory, Structure, and - prominent neurologist and Function embryologist - in 1852, published convincing...

Lesson 1: Cell Theory, Structure, and - prominent neurologist and Function embryologist - in 1852, published convincing evidence that cells are derived Cells from other cells as a result of - primary building blocks of life cell division - come in all shapes and sizes - smallest cell: Mycoplasma Rudolf Virchow gallicepticum (0.3 nm) - well-respected pathologist - largest cell: ostrich egg (6 in) - in 1855, published an editorial essay entitled, “Cellular Cell Theory Pathology,” which popularized the concept of cell theory using 1. All organisms are made up of cells. the Latin phrase, “omnis cellula - the cell is the structural & a cellula,” (all cells arise from functional unit of all living things cells) which is essentially the second tenet of modern cell Robert Hooke theory - first recorded cells around 1665 - was improving his microscope 3. Cells contain hereditary information design when he decided to which is passed from cell to cell observe a piece of cork and during cell division. saw box-like structures (cell - life depends on the ability of walls) cells to store, retrieve, and translate the genetic instructions Profound Postulates of Cell Theory required to make and maintain a living organism Matthias Schleiden - these instructions are stored as - German botanist genes, which contain elements - made extensive that determine the microscopic characteristics of a species as a observations of plant whole and the individuals within tissues in 1838 it Theodor Schwann 4. All cells are basically the same in - German physiologist chemical composition. - made similar - hydrogen, oxygen, nitrogen, observations in animal carbon, phosphorus, and tissues in 1839 sulfur normally make up more than 99% of the mass of living These laid the foundation for the cells and form virtually all known idea that cells are fundamental organic biomolecules components of plants and - they are utilized in the synthesis animals. of a small number of building blocks that are in turn used in 2. All cells come from pre-existing cells the construction of by division. macromolecules (nucleic acids, proteins, Robert Remark polysaccharides, and lipids)  5. All energy flow (metabolism & - processes the proteins produced by the biochemistry) of life occurs within endoplasmic reticulum and ribosomes, cells. modifying and storing them until it - nutrients and other molecules packages them into vesicles are imported into the cell to - Lysosomes meet these energy demands - sacs containing enzymes - cellular processes such as the capable of breaking down cell building and breaking down macromolecules of complex molecules occur through step-wise chemical Storage Organelles reactions Vesicles Major and Subcellular Organelles - membranous sacs that transport or store a variety of compounds Nucleus - the storehouse of genetic information in Vacuoles the form of DNA inside the cells - fluid-filled sacs for the storage of materials needed by the cell including Cell Membrane water, food molecules, inorganic ions, - a plasma membrane in plants that lies and enzymes just underneath a rigid layer (cell wall), giving protection, support, and shape to Energy-Producing Organelles the cell - in plants and algae, the cell wall Mitochondria is made up of polysaccharide - sites of cellular respiration cellulose - break down sugar to fuel the cell Cytoplasm Chloroplasts - fills the space between the nucleus and - contain chlorophyll the cell membrane - photosynthesis occurs within them, - cytosol is the fluid portion consisting allowing plant cells to form sugar from mainly of water and excluding the air, water, and light organelles in it Breakdown Organelles Manufacturing Organelles Lysosomes Endoplasmic Reticulum - contain powerful enzymes that can - an extensive membrane complex defend a cell from invading bacteria and extending throughout the cytoplasm viruses from the outer membrane of the nuclear envelope Peroxisomes - Rough Endoplasmic Reticulum - contain digestive enzymes for breaking - contains ribosomes that down toxic materials produce proteins - Smooth Endoplasmic Reticulum Structural Support, Movement, and - manufactures lipids Communication Organelles Golgi Apparatus Cytoskeleton  - made up of a small protein subunit, Cytoplasm forming long threads or fibers that can ○ jelly-like fluid within a cell that is crisscross the entire cell providing sturdy composed primarily of water, mechanical support salts, and proteins Centrosome Ribosomes - small dense region of cytoplasm that ○ organelles that make proteins serves as the main microtubule organizing center Differences Feature Eukaryotic Prokaryotic Cilia & Flagella - two locomotory projections in Nucleus - nucleus - no nucleus eukaryotes surrounded by - membraneless - cilia look like hairs while flagella look nuclear envelope nucleoid region - free floating DNA like a tail Organelles - membrane - appendages from Lesson 2: Prokaryotic and Eukaryotic bound organelles the cell surface such as (flagellum, Cells mitochondria, fimbriae, pili) rough and - bacteria may Three Basic Domains of All Living Things smooth ER, and have golgi complex carboxysomes - Bacteria (P) - Archea (P) Ribosomes - bigger, more - smaller and free - Eukarya (E) complex, and floating membrane - 50-s & 30-s bounded subunits Prokaryotes - 60-s & 40-s - primarily single-celled organisms - smallest, simplest, and most ancient Reproduction - sexually or - binary fission or cells through mitosis genetic variations ( transformation, Eukaryotes transduction, - made up of more complex cells conjugation) - can be unicellular or multicellular Cell Walls - fungal cell walls - rigid wall made - include animals, plants, fungi, and are made up of up of protists chitin peptidoglycans - vertebrates do not have cell Common Features walls DNA ○ genetic coding that determines Plant Tissues and Cells all the characteristics of living things Plant Cells - formed at meristems and develop into Cell (or Plasma) Membrane cell types, which are grouped into ○ outer layer that separates the tissues cell from the surrounding - Dermal environment and acts as a - Ground selective barrier for incoming - Vascular and outgoing materials Dermal Tissue (EG) Muscle Tissue (SSC) - covers the outer surface of herbaceous - facilitates movement of the animal by plants contraction of individual muscle cells - Epidermal - Skeletal Muscle Fiber - Guard - Smooth Muscle Fiber - Cardiac Ground Tissue (PCS) - comprises the bulk of the primary plant Nervous Tissue (NG) body - integration of stimulus and control of - Parenchyma response to stimulus - Collenchyma - Nerve - Sclerenchyma - Glial Vascular Tissue (PCX) Plants Animals - transports food, water, hormones, and minerals within the plant DGV ECMN - Xylem - Phloem D - EG E - SCC - Cambium G - PCS C - BBL V- PCX M - SSC 3N - NG Animal Tissues and Cells Animal Cells Lesson 3: Microscopy - Epithelial - Connective Microscope - Muscle - used to view objects too small to be - Nervous seen with the unaided eye Epithelial Tissue (SCC) Antonie van Leeuwenhoek - covers body surfaces and lines body - observed first living cells using his own cavities single lens microscope in 1676 - protects and forms glands - Squamous Epithelium Types of Microscopes - Cuboidal Epithelium Simple Microscope - Columnar Epithelium Compound Microscope Electron Microscope Connective Tissue (BBL) ○ SEM (Scanning Electron) - binding, supporting, protecting, forming ○ TEM (Transmission Electron) blood, storing fats, and filling space - Bone Simple Microscope - Loose Connective Tissue - the first microscope - Adipose - can magnify between 200 and - Areolar 300 times; essentially a - Reticular magnifying glass - Blood - combined convex lens - RBC - not used often due to the - WBC introduction of a second lens - Platelets Compound Microscope Mechanical Parts - most common microscope found in labs - give support and strength - uses two lenses Magnifying Parts - involved with magnifying power Monocular Microscope Illuminating Parts - one ocular lens - used to collect light for better resolution Binocular Microscope - two ocular lenses Calculating Magnifying Power - can be determined by multiplying the Electron Microscope magnification power of the ocular lens to - uses electron beams to magnify an the magnification power of the objective object lenses Scanning Electron Microscope - uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens - magnification ranging from 20X to approximately 30,000X, spatial resolution of 50 to 100 nm - used to generate high-resolution images of shapes of objects and to show spatial variations in chemical compositions Storing the Microscope Transmission Electron Microscope 1. Turn the nosepiece to put the LPO or - uses electrons in creating a magnified the scanner back into position. image, and samples are scanned in a 2. Raise the body tube or lower the stage vacuum with the coarse adjustment knob to - magnification up to 250,000x prevent the lens from striking the stage - can reveal the finest details of internal accidentally. structure 3. Turn off the light if your microscope light source is an electric light bulb. Parts and Functions of a Compound 4. Use a clean piece of lens paper, wipe Microscope the ocular and the objective lenses gently. Lesson 4: Cell Reproduction Cell Division - all cells are derived from pre-existing cells - new cells are produced for growth and to replace damaged or old cells - differs in prokaryotes (bacteria) and eukaryotes (protists, fungi, plants, and animals) DNA - examples are mitosis and binary fission - where the instructions for making cell parts are encoded Sexual Reproduction - each new cell must get a complete set - involves two cells (egg and sperm) of DNA molecules joining to make a new cell (zygote) that - must be replicated before cell division; is not identical to the original cells each new cell will then have an identical - an example is meiosis copy of the DNA (one parent cell creates two identical daughter cells) Cell Division in Prokaryotes - they divide into 2 identical cells by the Prokaryotic Chromosomes process of binary fission - the DNA of prokaryotes is one, circular - a single chromosome makes a copy of chromosome attached to the inside of itself the cell membrane - cell wall forms between the chromosomes, dividing the cell Eukaryotic Chromosomes - all eukaryotic cells store genetic Cell Cycle information in chromosomes - most eukaryotes have between 10 to 50 chromosomes in their body cells Interphase - humans have 46 chromosomes or 23 G1 - primary growth phase identical pairs S - synthesis; DNA replication - each chromosome is composed of a G2 - secondary growth phase single, tightly coiled DNA molecule Mitosis (M) - can’t be seen when cells aren’t Prophase dividing (called chromatin) Metaphase Anaphase Compacting DNA into Chromosomes Telophase - DNA is tightly coiled around proteins Cytokinesis (C) called histones Interphase Chromatids - duplicated chromosomes called sister G1 Stage chromatids - first growth stage after cell division - held together by the centromere - cells mature by making more cytoplasm and organelles Karyotype - cell carries on its normal metabolic - a picture of a human cell’s activities chromosomes arranged in pairs by size - the first 22 are called autosomes S Stage - last pair are the sex chromosomes (XX - synthesis stage for females and XY for males) - DNA is copied or replicated Types of Cell Reproduction G2 Stage - second growth stage; after DNA has Asexual Reproduction been copied - involves a single cell dividing to make 2 - all cell structures needed for division new, identical daughter cells (e.g. centrioles) are made  - both organelles and proteins are synthesized Anaphase - occurs rapidly Mitosis - sister chromatids are pulled apart to - division of the nucleus; also called opposite poles of the cell by kinetochore karyokinesis fibers - only occurs in eukaryotes - doesn’t occur in some cells such as Telophase brain cells - sister chromatids at opposite poles - spindle disassembles Early Prophase - nuclear envelope forms around each - chromatin in nucleus condense to form set of sister chromatids visible chromosomes - nucleolus reappears - mitotic spindle forms from fibers in - cytokinesis occurs cytoskeleton or centrioles (animals) / - chromosomes reappear as chromatin microtubules (plants) Cytokinesis Late Prophase - division of cytoplasm - nuclear membrane and nucleolus are - division of cell into two, identical halves broken down or have disintegrated called daughter cells - chromosomes continue condensing and - in plants, cell plate forms at the equator are clearly visible to divide the cell; in animals, cleavage - spindle fibers called kinetochores furrow forms attach to the centromere of each chromosome Daughter Cells of Mitosis - spindle finishes forming between the - have the same number of chromosomes poles of the cell as each other and as their parent cell - identical to each other but smaller than Spindle Fibers parent cell - must grow in size to become mature Polar Fibers cells (G1 of Interphase) - extend from one pole of the cell to the opposite Cell Division in Eukaryotes - used for growth and repair Kinetochore Fibers - produces two new cells identical to the - extend from the pole to the original cell centromere - cells are diploid (2n) Asters Uncontrolled Mitosis - short fibers radiating from - unlimited cell division occurs, causing centrioles cancerous tumors - oncogenes are special proteins that Metaphase increase the chance of a normal cell - chromosomes, attached to developing into a tumor cell kinetochores, move to the center of the cell Meiosis - chromosomes are now lined up at the - the fundamental basis of sexual equator reproduction  - preceded by interphase which includes - homologous pair chromosome replication - crossing-over (pieces of chromosomes - two meiotic divisions (Meiosis I and or genes are exchanged; produces Meiosis II) genetic recombination in the offspring) - called reduction-division - original cell is diploid (2n) but four Late Prophase I produced daughter cells are haploid - chromosomes condense (1n); they contain half the number of - spindle forms chromosomes as the original cell - nuclear envelope fragments - produces gametes (eggs and sperm) - occurs in the testes for males Five Substages of Prophase I (spermatogenesis) or the ovaries for females (oogenesis) Leptonema - occurs in germ cells that produce - replicated chromosomes have coiled gametes and are already visible - reduces the chromosome number by - number of chromosomes is the same as half so fertilization can then restore the the number in the diploid cell 2n number (two haploid gametes form a diploid zygote) Zygonema - homologue chromosomes begin to pair and twist around each other in a highly specific manner called synapsis - because the pair consists of four chromatids it is referred to as bivalent tetrad Pachynema - chromosomes become much shorter and thicker - a physical exchange between homologs called crossing-over takes place at specific regions Diplonema - two pairs of sister chromatids begin to separate from each other - after crossing over, the area of contact between two non-sister chromatids called chiasma becomes evident Diakinesis - four chromatids of each tetrad are even more condensed and the chiasma often Prophase I terminalize or move down the - chromosome number is doubled chromatids to the ends; this delays the - homologous chromosomes join to form separation of homologous tetrads (called synapsis) chromosomes Early Prophase I  - nucleoli disappear and the nuclear - men produce about 250,000,000 per membrane begins to break down day Metaphase I Oogenesis - homologous pairs align along the - occurs in the ovaries equator of the cell - two divisions produce 3 polar bodies that die and 1 egg Anaphase I - polar bodies die because of unequal - homologs separate and move to division of cytoplasm opposite poles - immature egg is called an oocyte - sister chromatids remain attached at - starting at puberty, one oocyte matures their centromeres into an ovum every 28 days (menstrual cycle) Telophase I - nuclear envelopes reassemble and spindle disappears Mitosis Meiosis - cytokinesis divides cell into two Divisions 1 2 Meiosis II Daughter Cells 2 4 Genetically Yes No Identical? Number of Same as Half of Chromosomes parent parent Where Somatic Germ Cells Cells When throughout at sexual life maturity (essentially the same as mitosis but doubled) Role Growth and Sexual Repair Reproduction Results of Meiosis - gametes form Lesson 5: Chromosomal Aberrations - four haploid cells with one copy of each chromosome - disruptions in the normal chromosomal - one allele of each gene content of a cell - different combinations of alleles for - morphological or numerical alteration of different genes along the chromosome chromosomes - affects autosomes, sex chromosomes, Gametogenesis or both - Deletion, Duplication, Inversion, Spermatogenesis Translocation - occurs in the testes - originates as a result of an error during - two divisions produce 4 spermatids that meiosis (nondisjunction), specifically in mature into sperm ANAPHASE stage Klinefelter Syndrome - people born with an extra X, causing Physical Characteristics their cells to have XXY chromosomes - excessive drooling - happens randomly during conception - behavioral problems - often intellectually disabled Physical Characteristics - gastrointestinal and cardiac - weaker bones; osteoporosis complications - heart and blood vessel disease - abnormal development of larynx and - diabetes glottis - underactive thyroid gland (hypothyroidism) - autoimmune diseases like rheumatoid Jacobsen’s Syndrome - arthritis, lupus - deletion of a terminal region of - a rare tumor called an extragonadal chromosome 11 that includes band 11 germ cell tumor q 24.1 - male breast cancer (although this is - rare congenital disorder also known as quite rare) 11 q deletion disorder - can cause intellectual disabilities, a distinctive facial appearance, and a Wolf-Hirschhorn Syndrome variety of physical problems including - deletion of short arm of chromosome 4 heart defects and a bleeding disorder - also known as Pitt-Rogers-Danks - first identified by Danish physician Petra Syndrome or Pitt Syndrome Jacobsen and is believed to occur in 1 - first described in 1961 by Herbert L. out of every 100,000 births Cooper and Kurt Hirschhorn Physical Characteristics Physical Characteristics - bleeding disorder - short philtrum - heart defects - immunodeficient - wide set eyes - microcephaly (small head) - low set misshapen ears - seizures - large toes - muscle hypotonia - renal anomalies - deafness Pallister-Killian Syndrome - presence of the anomalous extra isochromosome 12p, the short arm of Cri Du Chat Syndrome the twelfth chromosome (Tetrasomy - - deletion of short arm of chromosome 5 2n+2 or 48 chromosomes) - also known as chromosome 5p - mosaic condition and extremely rare deletion syndrome, 5p minus genetic disorder also known as syndrome, or Leejeune’s syndrome Tetrasomy 12p Mosaicism or Pallister - a French term meaning, “cat-cry” or “call Mosaic Aneuploidy Syndrome of the cat” referring to the characteristic catlike cry of affected children Physical Characteristics - first described in 1963 by Jerome - hypo/hyper pigmentation Leejeune - epilepsy - affects 1 in 50,000 live births, strikes all - high foreheads ethnicities, and is more common in - flat nose females by a 4:3 ratio - supernumerary nipples  - psychomotor retardation - identified as a chromosome 21 Trisomy by Dr. Jerome Lejeune in 1959 Patau Syndrome Physical Characteristics - additional chromosome 13 (Trisomic - - epicanthal folds in the eye 47 chromosomes) due to - short stature and short neck non-disjunction during meiosis, causing - delayed language development heart and kidney defects - tongue tends to stick out of the mouth - some are caused by Robertsonian - some are mentally retarded Translocations - flattened face, especially nose bridge - also known as Trisomy 13 and Trisomy D - affects between 1 in 10,000 and 1 in 21,700 live births Physical Characteristics - polydactyl - cleft palate - cutis aplasia - kidney failures Isodicentric 15 - 47 chromosomes instead of 46 - extra genetic material in chromosome 15 Physical Characteristics - poor muscle tone in newborn - developmental delay - flattened nasal bridge - button nose - high arched palate - some features of autism Trisomy 21 - extra genetic material in chromosome 21 (47 chromosomes) - average IQ of affected children is 50 (normal is 100) - Down Syndrome - named after John Langdon Down, the British physician who described the syndrome in 1866 - clinically described earlier in the 19th century by Jean Etienne Dominique Esquirol in 1838 and Edouard Seguin in 1844