Biology lab 111 - JUfilesjufiles.com/wp-content/uploads/2016/05/biology-lab-111.pdf · Biology lab...
Transcript of Biology lab 111 - JUfilesjufiles.com/wp-content/uploads/2016/05/biology-lab-111.pdf · Biology lab...
Biology lab 111
Experiment 3: the microscope: - The unaided eye has a resolving power of about 0.1mm - Light microscope has a resolving power of about 2 - Light microscope can improve resolution as much as 1000 times, compared to the unaided eye - Contrast means increasing differences between the lightest and the darkest parts of an image - The microscope is carried by holding the arm with one hand and supporting the base with the other
hand
Light microscope systems: 1- Mechanical 2- Illuminating 3- Imaging
Mechanical parts: 1- Tube 2- Arm 3- Nosepiece 4- Base 5- Stage 6- Focusing knob
Imaging parts: 1- 3-4 objective lenses 2- 1-2 ocular lenses
Illuminating parts: 1- Light source 2- Condenser lens 3- Iris diaphragm - Focusing knobs are coarse adjustment knob and fine adjustment knob - If air bubbles present in wet mount preparation, such bubbles appear as circles of various sizes with
dark edges - Always start your microscopic study with the 4X objective lens - Never use coarse adjustment knob when you view a specimen with the 40X objective lens
Total magnification = objective lens magnification * ocular lens magnification
- The image of the specimen in the light microscope is inverted
Types of microscopes:
1- Light microscope 2- Dissecting microscope 3- Phase contrast microscope 4- Transmission electron microscope 5- Scanning electron microscope
Dissecting microscope: - Has two oculars and two tubes
Disadvantages: 1. Limited magnification and resolution
Advantages: 1- 3D image 2- Larger working distance 3- Viewing large objects
Phase contrast microscope: - Studying alive specimen without killing them
Transmission electron microscope: - Electron beams are used as a source of illumination instead of light waves - Operated under vacuum - Has electromagnetic lenses - Magnification can reach 1,000,000 - Resolution may reach 0.2nm - Specimen has to be cut into sections as thin as 60-100nm and must be stained with heavy metals to
make them electron dense
Scanning electron microscope: - The surface of the specimen must be coated with a thin layer of gold - The energy in the electron beam makes the gold emits more electrons which are picked up by a
detector - Results in a picture of the surface of the specimen on a cathode ray tube
Experiment 4: the cell: - All cells have a plasma membrane, a region of DNA or nucleus, and a cytoplasm
Types of cells: 1- Prokaryotic 2- Eukaryotic - Prokaryotic cells are bacteria, compose the domains eubacteria and archeabacteria
Eukarya kingdoms:
1- Animals 2- Plants 3- Protists 4- Fungi - Eubacteria include bacteria and cyanobacteria
Bacteria shape: 1- Bacilli 2- Spirilli 3- Cocci
Bacteria in yoghurt: - Yoghurt contain lactobacillus
- Lactobacillus adapted to live on lactose and converts milk to yoghurt - Methelyne blue pigment used
Cyanobacteria: - Photosynthesis prokaryotes - Exist as colonies and filaments and as a single cells - A slide of anabaena which is a filamentous cyanobacteria is used to observe cyanobacteria
Eukaryotic cells kingdoms: 1- Protists 2- Animalia 3- Plantae 4- Fungi - Nucleus and mitochondria and chloroplast are membrane bound structure
Human cheek cells: - Protection function - Methylene blue is used
Human skin cells: - Methylene blue is used
Onion epidermal cells: - The onion is made up of thickened modified leaves called scales - The onion epidermal cells comes from a thin translucent tissue which lines the scales outer curve - Lugol's stain is used
Experiment 5: biological macromolecules: Classes of macromolecules:
1- Carbohydrate 2- Lipids 3- Proteins 4- Nucleic acids - The chemical properties of classes depend on functional groups - Dehydration is joining building blocks - Hydrolysis are breaking down of polymers
Carbohydrates: - Glucose is a 6 carbon aldose - Fructose is a 6 carbon fructose - Two glucose molecules form maltose - Glucose and fructose form sucrose - Glucose and galactose form lactose
Polysaccharides examples: 1- Starch 2- Glycogen 3- Cellulose 4- Chitin
Benedict's test: - To detect reducing sugars - Reducing sugars have free aldehyde or ketone groups - Benedict reagent consist of CuSO4 making it blue colored - The positive sign is orange-brownish color - This test needs boiling
Lugol's test: - To detect starch - Yellowish-brown color is a negative sign - Bluish-black color is a positive sign - Iodine only interact with coiled molecules - Doesn't need boiling
Proteins: - The building block of proteins are amino acids - Amino acid are linked together by a peptide bonds
Proteins types: 1- Structural 2- Regulatory 3- Storage 4- Contractile 5- Transport
Ninhydren test: - To detect amino acids - Ninhydren reagent reacts with free amino groups - A purple or violet color is the positive sign - Need boiling
The biuret test: - To detect peptide bonds - A violet color is the positive sign - Doesn't need boiling
Lipids: Lipid classes:
1- Neutral fats 2- Phospholipids 3- Steroids
- Cholesterol is an example of steroids
Sudan red test:
- To detect lipids
- A red color is a positive sign
- Doesn't need boiling
- The final step is mixing with vortex
Lipid solubility test:
- Lipids are soluble in nonpolar solvents such as alcohols
- To detect the solubility of lipids
- The final step is mixing
The grease spot test:
- The spread of oil on a paper sheet to give a transparent spot
Nucleic acids: Types of nucleic acids:
1- DNA 2- RNA
Types of nitrogenous bases: 1- Purines 2- Pyrimidines
Purine types: 1- Adenine 2- Thymine 3- Cytosine 4- Guanine
- Uracile is found only in RNA instead of Thymine
- Pyrimidine have only one ring while purine have two
Extraction of DNA:
- The final step is to invert the tube several times
The Dische diphenylamine test:
- To detect DNA
- A blue color is a positive sign
- Need boiling
Experiment 6: enzymes:
- Most enzymes are proteins
Enzyme categories: 1- Hydrolytic 2- Oxidizing 3- Reducing
- Enzymes are categorized depending on the type of reactions they control
- Rennin coagulate milk protein which is casein
- Catechol oxidase react with catechol to give a dark brown color
Factors affecting enzyme activity:
- Rennin alters the 3D structure of casein
- Rennin allows the digestion of milk to be more effective by slowing its passage through the digestion system
Factors affecting enzyme activity:
1- Temperature 2- Ph 3- Enzyme concentration
Temperature:
- High temperatures denaturate the active site of the enzyme
- Low temperature stops the enzyme activity
- Enzyme can survive low temperatures but not the high temperatures
PH:
- Enzyme can't work in acidic or basic solutions
Catechol oxidase test:
- To detect catechol oxidase
- By adding catechol to the reaction mixture
- Dark brown color is the positive sign
- Catechol oxidase forms benziquinone
- Catechol is poisonous
- Phenylthiourea is an inhibitor of catechol oxidase
- Phenylthiourea must be added to solution before the enzyme to inhibit its activity before completing its job
Experiment 7: physical properties of the cell:
- Brownian movement has been discovered by Robert brown
- Diffusion is the movement of molecules from higher concentrations to lower concentrations
- An example of diffusion within liquids is the addition of liquid dye to water
Observing Brownian movement:
- We use carmine dye to observe it
Effect of temperature on Brownian movement:
- Temperature and Brownian movement are proportionally related
- As the temperature increases the Brownian movement increases
Diffusion within solution:
- Starch and iodine = color change inside the bag only
- Iodine move inside the bag where the starch located
- Phenolphthalein and sodium hydroxide = color changes in and outside
Diffusion within semisolid medium:
- The less the molecular weight the bigger the diameter
Osmosis:
- Osmosis is the diffusion of water across a selectively permeable membrane
- Hypotonic means greater concentration in the cell
- Isotonic means equal concentrations
- Hypertonic means less concentration in the cell
Osmosis in plant cell:
- We use elodea or onion epidermal cells to observe the osmosis in the plant cells
Osmotic pressure:
- We will use osmometer
- Osmometer is filled with molasses or sugar solution
- The height of the solute in the tube increases as the concentration of sugar increases
Experiment 8: metabolism: Examples of photosynthetic autotrophs:
1- Green plants 2- Some monera 3- Some protists
Examples of heterotrophs: 1- Most monera 2- Some protists 3- All fungi 4- All animals
- Anabolism is synthesis reaction
- Catabolism is breaking down reaction
Respiration: Alcoholic fermentation:
- Carried out by yeast in an anaerobic process
- Oxygen-stressed muscles of animals carry out lactic acid fermentation
Measuring yeast fermentation:
- Baker's yeast, sacharomyces cerevisiae is used
- Starch is converted to glucose
- Respirometer is a set to see fermentation
Cellular respiration:
- Respiration is a catabolic reaction
Ways to measure cellular respiration: 1- Consumption of O2
2- Production of CO2
3- Release of energy during cellular respiration
Production of CO2during aerobic respiration:
- The change in the volume of gas in the respirometer will be directly related to the amount of oxygen consumed
- During respiration, oxygen will be consumed and its volume will be reduced because carbon dioxide produced is being converted to a solid
Iodoform test:
- To detect alcohol
- Secondary alcohols with an adjacent methyl group react with iodine in alkaline medium
- A yellow precipitate is a positive sign
Photosynthesis:
- Carbon dioxide from the atmosphere provides the carbon source for photosynthesis
- Water provides the hydrogen source for photosynthesis
- Chlorophyll pigment are necessary to trap the light
Demonstration of photosynthesis:
- We use elodea to demonstrate photosynthesis
- As we increase the light intensity the photosynthesis reaction increases
- If we add a source of CO2 the photosynthesis reaction increases
- The source that we use is sodium bicarbonate
Extraction and separation of photosynthetic pigments:
- The most polar pigment will be the lowest
- We use a paper chromatography
- We use a pencil and aceton
- The highest pigment is carotenes the xanthophylls pigment then chlorophyll a and the lowest is chlorophyll b pigments
Experiment 9: cell division:
- Cells have many specialized functions one of which is division
- Dividing cells undergo a repeated sequence of events called cell cycle
Cell cycle stages: 1- Interphase 2- Mitosis 3- Cytokinesis
Interphase phases: 1- Gap 1 G1
2- Synthesis S 3- Gap 2 G2
- Mitosis results in two nuclei containing identical chromosomes
- Mitosis is called equational division, because the resulting cells have equal number of chromosomes
- In interphase the cellular material is being doubled
Mitosis stages: 1- Prophase 2- Metaphase 3- Anaphase 4- Telophase
- Meiosis or reductional division, resulting in cells have half the chromosomes in the mother cell
- In prophase the chromosomes is being condensed
- In metaphase the chromosomes are aligned to the center of the cell
- In anaphase the each centromeres split
- In telophase the cytoplasm is being constricted and split into half
Mitosis in animal cells:
- A slide of white fish blastula is used in this experiment
Mitosis in plant cells:
- A slide carrying a longitudinal section of an onion root tip is used in this experiment
- Mitosis is active at apical meristem
The differences between mitosis in animal and plants: 1- Cytokinesis in plant cell takes place by formation of a cell plate, and not by construction as in
animal cells 2- Lack of centroiles, and consequently astral rays in plant cells
Meiosis in animal cells:
- Occurs in reproductive organ
- It involves prophase, metaphase, anaphase, and telophase
- It happens in two stages meiosis I and meiosis II
- Homologues are chromosome pairs found in body cells
- Diploids have all homologues in it
- Haploids have half the homologues in it
- Meiosis I involves the reduction
- Meiosis II ends up in daughter
- Nematode worm called ascaris is used in this experiment
- Oogenesis is egg formation in ascaris
- Meiosis II doesn't consist of prophase
Experiment 10: Genetics:
- Genes are units of DNA which is located in chromosomes
- Alleles are genes that occupy identical positions on the homologues
- Meiosis produce gametes with 23 chromosomes
- The process that happens during meiosis is called segregation
- Homozygous have two similar alleles
- Heterozygous have two different alleles
- The dominant allele hides the recessive allele
- Codominant are two dominant allele
- Incomplete dominance is intermediate between two homozygotes
- Autosomes are 22 pair of chromosomes
- Sex chromosomes are the last pair of chromosomes
- The genes located on the X chromosome are called sex linked genes
Dominant and recessive traits in humans:
- You only need one copy of a dominant gene in order to see a dominant phenotypic trait
- You need two copies of a recessive gene in order to see a recessive phenotypic trait
Working with human phenotypes: Examples of human phenotypes:
1- PTC tasting 2- Tongue rolling 3- Thumb binding 4- Hair texture 5- Ear lobes 6- A-B-O Blood types
PTC tasting:
- Tasting PTC is determined genetically, its harmless and produces a very bitter taste
- Its dominance
Tongue rolling:
- Tongue rolling is dominant
Thumb binding:
- The hitchhikers thumb is recessive
- Thumb tip bends backward more than 60o
Hair texture:
- Curly hair is incompletely dominant to straight hair
- Wavy hair is intermediate
Ear lobes:
- The detached lobes are dominant
A-B-O blood types:
- Type A contains B antigens
- Type B contains A antigens
- Type O contains Both
- Type AB contains neither A nor B
- The allele of A and B are codominant
- The blood types are detected by mixing drops of the blood with sera containing the A antibody and the B antibody
- Clumping A antibody indicates A type
- Clumping B antibody indicates B type
- No clumping indicates O type
Drosophila melanogaster genetics:
- Drosophila melanogaster is the fruit fly
- Complete its life cycle in 10 to 12 days
- It contains 4 pairs of chromosomes
Differences between male and female fruit flies: 1- Only males have a sex comb 2- The tip of the abdomen is more rounded in males 3- Posterior part of the abdomen is more darker in males and lighter in females 4- Females are larger than males
Examining mutant flies:
- The normal fly is called a wild type
- A mutant fly is any fly exhibiting a phenotypic mutation
- The mutant ebony has a much darker body
- Flies with vestigial wings can't fly they have a defect in the vestigial wings and is called melanogaster mutant
- Yellow flies have a complete yellow body
- White eyed flies have white eyes and are called white eyed mutants
Chi square goodness of fit test:
- Used to compare the observed result with the theoretically expected distribution
Experiment 11: plant tissue: Plant tissue groups:
1- Meristematic 2- Permanent
- Meristematic tissue go through division
- Permanent tissue doesn’t go through division
Types of permanent tissue: 1- Simple 2- Complex
Types of simple permanent tissue: 1- Parenchyma 2- Collenchymas 3- Schlerenchyma 4- Epidermis
Types of complex permanent tissue: 1- Xylem 2- Phloem
Meristematic tissue:
- Composed of embryonic undifferentiated cells
- Apical meristem found at the growing tips
- Apical meristem is responsible for the sustained increase in length of the plant body
- Primary tissue are produced by the apical meristem
- Lateral meristem such as vascular cambium and cork cambium are responsible for the sustained increase in diameter
- After each cell division one of the two daughter cell stays meristematic and the other becomes a part of the plant body
- Tissues produced by the lateral meristem are secondary tissue
Shoot and root apical meristem:
- We use a slide of longitudinal section of coleus shoot tip and a slide of longitudinal section of an onion root tip
Permanent plant tissue Simple permanent tissue: Parenchyma tissue:
- Thin walled (primary and secondary cell walls) and have inter cellular spaces
- Parenchyma are alive at maturity
- Parenchyma is the most common ground tissue
Parenchyma functions: 1- Photosynthesis 2- Respiration 3- Storage 4- Secretion
- We use a cross section of helanthus stem to see parenchyma tissue
Areas of parenchyma: 1- Cortex 2- Pith
- The cortex is the area between the epidermis and the vascular bundles
- The pith is the area in the center of the stem
- Chlorenchyma is a parenchyma cell that contain chloroplast
Collenchyma tissue:
- Consist of living elongated cells
- Irregularly thickened primary walls
- Structural support function
- They are flexible
- Cell walls are thinner than sclerenchyma cell walls
Sclerenchyma tissue:
- Composed of rigid cells that have lignified secondary walls
- Dead at maturity
Sclerenchyma types: 1- Sclereids 2- Fiber
- Sclereids are small irregularly shaped
- Fibers are long and thin and occur in strands
Sclerenchyma functions:
1- Protection 2- Mechanical support
- Internal spaces are nearly obliterated
Epidermal tissue:
- Forms a protective outer covering of the plant body
- 1 cell thick but may be thicker in species that live in very dark habitats and where protection against water loss is critical
- Epidermal cells on the shoot are covered with cuticle
- Cuticle is waxy water resistant material
Complex permanent tissue:
- Composed of more than one type of cells
- Including vascular tissue and periderm
Vascular tissue:
- Vascular tissues are xylem and phloem
- Xylem conduct water and minerals
- Phloem conduct photosynthesis products
- Xylem is composed of parenchyma, fibers, vessels, and trachieds
- Phloem is composed of parenchyma, fibers, sieve tubes, and companion cells
The periderm:
- Located at the outer most layers of woody stems and roots
- Forms the bark
- Composed of cork cells, cork cambium, and phelloderm
- Cork cells is toward outer side, and phelloderm is toward inner side
- We use a slide of tilia
Experiment 12: animal tissues:
- Cells makes tissue, and tissue make organs, and organs make system, and systems makes organism
Example of organs:
1- Stomach 2- Nose 3- Limbs 4- Heart
Example of systems:
1- Reproductive 2- Digestive 3- Nervous 4- Circulatory
- Histology is the science which deals with the study of tissue
Types of tissues: 1- Epithelial 2- Connective 3- Muscular 4- Nervous
- Tissue sections are stained with hematoxylin which gives nuclei dark blue color and eosin which stains cytoplasm in light red color
Epithelial tissue:
- Covers body surfaces as in epidermis or line tubular organs as in the small intense
Function of epithelial tissues: 1- Protection 2- Secretion 3- Absorption 4- Sensation 5- Reproduction
Epithelial tissue features: 1- One free surface 2- Lack blood vessels 3- Very little intercellular spaces 4- Attach to a basement membrane
Simple squamous epithelium:
- Comprised of flat cells with a wide central part which contains a nucleus
- Involved in exchange of materials
- Location in alveoli of lungs and capillaries
Simple cuboidal epithelium:
- Consist of cells with almost equal sides
- Found in kidney tubules and thyroid follicles
- Involved in secretion or absorption
Connective tissues: Connective tissue functions:
1- Connection 2- Defense 3- Cushioning 4- Support 5- Protection 6- Storage of energy
- Comprised of cells, fibers, and ground substance
Types of fibers: 1- Collagen fibers 2- Elastic fibers
- Collagen fibers are tough and flexible
- Elastic fibers can stretch when pulled
- Ground substance may be hard as in bone, semihard as in cartilage, or liquid as in blood
- Connective tissue are highly vascular and lots of intercellular spaces
Types of connective tissue: 1- Proper 2- Special
Types of proper: 1- Loose 2- Dense
Types of special: 1- Blood 2- Adipose 3- Cartilage 4- Bone
Connective tissue proper: Loose connective tissue:
- Also called areolar connective tissue
- Consist of cells scattered in a matrix contains collagen and elastic fibers
- Have an important role in defense
- Found in mesentry
Dense connective tissue:
- Consist of tightly packed collagen fibers
- In regular shape the fibers are arranged parallel to each other
- A slide of longitudinal section of tendon
Special connective tissue: Blood:
- Platelets are the major component of blood
- Platelets are plasma and cellular materials
Types: 1- Leukocytes 2- Erythrocytes 3- Platelets
Leukocytes:
- White blood cells
- Have a defensive function
Types of leukocytes: 1- Neutrophile 2- Lymphocytes
Neutrophile:
- Granular cell with 3-5 lobed nucleus
Lymphocytes:
- Agranular cell with large round nucleus
Erythrocytes:
- Red blood cells
- Have a function in transport of O2 and CO2
- Hemoglobin is an example
- Its nonnucleated small red color cell
Platelets:
- Involved in blood clothing
Adipose: Adipose functions:
1- Storage of fat for energy 2- Thermal isolation 3- Protection
- Found under the skin and around internal organs
- Have no fibers
- An example of its cells is the adipocyte which is large cell with peripheral nuclei
- Have no intercellular spaces
Cartilage:
- Found in the end of long bone and respiratory tubes (trachea)
- Have a function of support
- It connects bone to bone
- Lack blood vessels
- Consist of semisolid gelatinous matrix called chondrin
- The cells of it is chondrocytes
- Chondrocytes cavities are lacunae
- One type of cartilage is hyaline which can be found in trachea and have no fibers
Bones:
- Has a function in support
- It’s a solid matrix from calcium phosphate salts called hydroxyapitite
- The matrix are called lamellae
- Compact bone found in long bone
- Compact bone are made by haversian systems
- Haversian systems cells are osteocytes
Haverisan systems consist of: 1- Osteocytes 2- Haversian canal 3- Lamellae
- Haversian canal consist of blood vessels and nerves
- Volkman's canal are made up by interconnected heversian canals
Muscular tissue:
- Contractile proteins are actin and myosin
- The cells of muscle tissue are either muscle cell or muscle fiber
Skeletal muscle:
- Have a function of movement
- Found in voluntary control organs
- They are striated and have multi peripheral nuclei
Nervous tissue:
- Found in brain, spinal cord, nerves and reach all organs
- The cells of it are nerve cell or neurons
- Neurons are specialized for transmitting impulse
Neuron types: 1- Axon 2- Dendrites
- Axon is long and carries impulses away from the cell body
- Dendrites are short and carries impulses toward the cell body
Experiment 13: vertebrate anatomy: Features that rats share with other mammals:
1- The prescence of hair on most parts of the body 2- The prescence of milk producing glands 3- Endothermy 4- Prescence of placenta and diaphragm
- Only study pictures
Experiment 16: plant anatomy: Groups of flowering plants:
1- Dicot 2- Monocot
Differences between dicots and monocots: 1- Leaf venation is usually parallel in monocots and net like in dicots 2- Flower parts are multiple of 3 in monocots and multiple 4 or 5 in dicots 3- The primary vascular bundles are scattered in stems of monocots and organized in dicots in a circle
The roots: Root functions:
1- Anchor 2- Absorption 3- Storage
- Absorption of water is done by lateral roots and root hairs
- Adventitious roots develop from the base of the stem
- The surface of young roots is formed of epidermis
- Under the epidermis is cortex
- Roots lack cuticle
- Endodermis is the intermost layer of the cortex
- Endodermis has secondary cell walls with lignin and suberin
- Lateral roots comes from the pericycle
- Vascular cylinder is in the middle of the root and consist of xylem and phloem
Internal anatomy of roots: Herbaceous dicots:
- We use a slide of cross section of ranunculus
Herbaceous monocots:
- We use a slide of cross section zea maize
Lateral roots:
- We use a slide of cross section zea maize
The stems:
- The main function is support
Leaf phyllotaxy types: 1- Alternate 2- Opposite 3- Whorled
- Alternate is one leaf at each node
- Opposite is two leaves at each node opposite to each other
- Whorled is three or more leaves at each node
- The internode space is the distance between two successive nodes
Modification of the stem: Modified stem types:
1- Stolons 2- Tubers 3- Rhizomes 4- Bulbs
- Stolons are the running stem horizontally above the ground
- An example of stolons is strawberry or spider plant
- Rhizomes are the horizontally running stem below the ground
- Bulbs are underground structure of shortened stem with modified fleshy leaves
- An example of bulbs is onion
The leaf:
- Consist of a petiole and a lamina
- Leaf venation is the vascular veins within the lamina
Leaf blades types: 1- Simple 2- Compound
Leaf venation types: 1- Parallel 2- Reticulate