SNC2D6 Science Exam Notes PDF

Science Exam Notes Unit 1 – Biology ​ Cell Theory -​ All living things are made up of one or more cells -​ The cell is the simplest unit that can carry out all life processes -​ All cells come from other cells; they do not come from non-living matter...

Science Exam Notes Unit 1 – Biology ​ Cell Theory -​ All living things are made up of one or more cells -​ The cell is the simplest unit that can carry out all life processes -​ All cells come from other cells; they do not come from non-living matter -​ History -​ ​ Cell Organelles ○​ Identify parts and their functions -​ Animal cell parts Cell Part Description of Function in the Structure cell Plasma Cell Selectively -​ Forms a Membrane permeable border protective of the cell. barrier Composed of a around the double layer of cell phospholipids -​ Allows different substances to move through it Cytoplasm Gel-like material -​ Helps to  made up of water move and dissolved materials minerals where (eg. cell organelles are nutrients suspended. and organelles) -​ Contains necessary nutrients -​ Gives the cell structure and protects organelles Nucleus Contains genetic -​ Controls all information. the Surrounded by activities in nuclear envelope. a cell -​ DNA replication, transcription , RNA processing Nucleolus Darker structure -​ Produce and within the nucleus assemble the cell’s ribosomes Nuclear Envelope Double membrane -​ Protect and (membrane) with nuclear pores separate the which surrounds contents of  the nucleus the nucleus from the cytoplasm Ribosome Produced in the -​ Protein nucleolus. Can be synthesis bound to the ER or freely floating in the cytoplasm. Centrioles A cylindrical -​ Helps with structure of 9 cell division triplets of tubes. -​ Organise Centrioles always microtubules exist as a pair. Rough Folded -​ Folds and Endoplasmic interconnected packages Reticulum membrane proteins covered in -​ Transportati ribosomes (rough) on of the that extends from proteins the nuclear envelope. Smooth Folded -​ Production Endoplasmic interconnected of fats and Reticulum membrane with oils NO ribosomes -​ Detoxificati (smooth) that on of drugs extends from the and toxins nuclear envelope. Golgi Apparatus Folded -​ Transport,  interconnected sort and membranes and modify vesicles near ER. proteins and lipids for use in other places inside and outside the cell Mitochondria A -​ Converts double-membrane chemical structure. The energy in inner membrane sugar into has many folds to energy the increase surface cell can use area. The innermost cavity is the matrix. Vacuole Fluid-filled sacs. -​ Stores food, waste, and water Vesicle Small celular -​ Transport containers materials Lysosome Contains digestive -​ Breaking enzymes. down nutrients -​ Breaking down excess/worn -out cell parts  -​ Destroy invading viruses and bacteria -​ Plant cell parts Cell Part Description of Function in the Structure cell Plasma Cell Selectively Membrane permeable border of the cell. Composed of phospholipids. Cytoplasm Gel-like material made of water and dissolved minerals where cell organelles are suspended. Cell wall A rigid wall that is -​ Provides  composed mostly strength, of cellulose. protection, and support -​ Selecctive barrier Nucleus Contains genetic information. Surrounded by nuclear envelope. Nucleolus Darker structure within the nucleus Nuclear Envelope Double membrane (membrane) with nuclear pores which surrounds the nucleus. Ribosome Produced in the nucleolus. Can be bound to the ER or freely floating in the cytoplasm. Rough Folded Endoplasmic interconnected Reticulum membrane covered in ribosomes (rough) that extends from the nuclear envelope. Smooth Folded Endoplasmic interconnected Reticulum membrane with NO ribosomes (smooth) that extends from the nuclear envelope. Golgi Apparatus Folded interconnected membranes and vesicles near ER. Mitochondria A double-membrane structure. The inner membrane has many folds to increase surface area. The innermost cavity is called the matrix. Chloroplast A -​ Site of double-membrane photosynthe structure. The sis inner membrane has many folds to increase surface area. The innermost cavity is called the stroma. It is  green in colour due to chlorophyll. Vacuole Fluid filled sacs. A very large one is located in plant cells and is identified as the central vacuole. ○​ Plant vs animal cells - what parts are only found in each? ​ Cell Cycle -​ The cell’s DNA instructs it on when to divide and when to die -​ Cells divide due to: -​ Growth -​ A cell’s nucleus grows much slower than the rest of the cell -​ A cell reaches a maximum size due to limitations in communication when the cell is too big -​ Reproduction -​ Binary Fission  -​ Budding -​ Asexual Reproduction -​ Sexual Reproduction -​ Repair -​ Normal replacement: due to cell lifespan -​ Maintenance: healing due to injury -​ Apoptosis = the regulated/controlled death of a cell -​ Interphase -​ 90% of cell cycle -​ Cell is doing its regular job -​ Prepares for duplication if triggered -​ 3 phases: -​ G1, S, G2 -​ Gap 1 (G1) - First Growth Phase -​ Period of rapid growth -​ New proteins and organelles are produced -​ Chromosomes are unwound into chromatin  -​ Prepares for DNA synthesis (S phase) -​ G naught (G0) - Resting Phase -​ Cell leaves cell cycle (inactive) -​ Can be temporary or permanent -​ Example: Neurons -​ DNA Synthesis Phase (S) -​ DNA is duplicated to ensure each cell will receive an identical set of DNA -​ Gap 2 (G2) - Second Growth Phase -​ Cell grows in size -​ Synthesizes more organelles and structures needed to split between the new cells -​ Eg. nucleolus are duplicated -​ Mitosis -​ Prophase -​ Chromatin condenses into visible chromosomes -​ Centrioles move to opposite poles of cell -​ Spindle fibres develop -​ Nuclear membrane breaks down -​ Metaphase -​ Spindle fibres align chromosomes along middle of cell ​ -​ Helps to ensure chromosomes separate properly -​ Anaphase -​ Sister chromatids are pulled apart by spindle fibres and move to opposite poles -​ Poles move apart by other spindle fibres involved in pushing  -​ Telophase -​ Chromosomes arrive at opposite poles -​ Chromosomes uncoil -​ Nuclear membrane reforms -​ Cytokensis -​ In animals: -​ Cell membrane pinches in at equator -​ Cell and the contents inside are split into two roughly equal parts -​ In plants: -​ Cell plate forms -​ New cell wall laid down between membranes and fuses with existing cell wall ​ Cell Specialization and Stem Cells -​ Specialized cells = Cells which conduct specific functions -​ Have physical and chemical differences that allow them to perform one job very well -​ Specialized cells are differentiated from an unspecialized stem cell -​ Stem cells are unspecialized cells that differentiate when signalled by environmental chemicals ​ Tissues -​ 4 major catergories of animal cells: Epithelial tissue (skin) -​ Lines and protects outer surfaces of organs Connective tissue (bone, fat, -​ Strengthens, protects, and blood) connects cells and tissues -​ Forms blood and protects  fat Muscle tissue (skeletal, smooth, -​ Allows for voluntary cardiac) movement -​ Cross-section: bundles of muscle fibres -​ Longitudinal section: striations Nervous tissue/cell (neurons) -​ Receives and responds to stimuli -​ Transmits signals -​ 4 types of plant tissues: Meristematic tissue -​ Unspecialized cells found throughout the plant to grow new parts Epidermal tissue -​ Outer protective cover tissue -​ Separates into upper epidermis and lower epidermis -​ Has guard cells and root hair cells Ground tissue -​ Stem: provides strength and support -​ Root: stores food and water -​ Leaves: conducts photosynthesis -​ Has storage cells and photosynthetic cells Vascular tissue -​ Moves water and nutrients throughout plant -​ Contains most of a plant’s xylem tissue & phloem tissue -​ Xylem tissue -​ One way flow -​ No end walls between cells -​ Transports water and minerals from the roots to other parts of the plant -​ Consists of two types of cells: tracheids and vessel elements -​ Both die at maturity and leaves their wall as hollow tubes that can be used for transport -​ Phloem tissue -​ Two way flow -​ End walls between cells -​ Transports water and food from the leaves to other parts of the leaves -​ Consists of two types of cells: sieve elements and companion cells -​ Both are alive at maturity ​ Stem cells -​ Animals -​ Embryonic stem cells -​ Only during the embryonic stage -​ Can collect and save umbilical cords at birth -​ Can differentiate into any kind of cell -​ Adult stem cells  -​ Can only differentiate into certain types of cells -​ Plants -​ Meristematic cells ​ Cancer Cells -​ Occurs due to a mutation in the DNA instructions -​ Can be caused by cell duplication errors or environment factors (eg. smoking, alcohol, obesity) -​ Characteristics -​ Many cells that continue to grow and divid -​ Variations in size and shapes of cells -​ Nucleus that is larger and darker than normal -​ Abnormal number of chromosomes arranged in a disorganised fashion -​ Cluster of cells without a boundary -​ Development of cancer: -​ Abnormal cells divide rapidly and form a clump (tumour) -​ Benign tumours: Non-cancerous, do not spread -​ Malignant tumours: Cancerous, spread, more likely to cause problems as they invade/affect other body structures and use the body’s nutrients -​ Metastasis: When abnormal cancer cells spread to other parts of the body through blood or lymphatic vessels -​ Diagnosis: -​ Blood tests, biopsy, imaging tests -​ Helps identify the staging of the cancer (type, size, spread) -​ Treatment:  -​ Main types include: -​ Surgery, chemotherapy, radiotherapy, immunotherapy, hormone therapy, gene therapy -​ Treatments could affect normal body cells that duplicate fast (eg. skin or hair) -​ Remission: A decrease in/disappearance of signs and symptoms of cancer -​ Recurrence: When cancer comes back after remission ​ Hierarchy of Structure -​ A hierarchy shows more complex levels at the top with simpler levels below -​ A biological hierarchy features 12 levels of organisation: -​ Ecosystem (largest/most complex) -​ Community -​ Population -​ Organism -​ Organ system -​ Organ -​ Tissue -​ Cell -​ Organelle -​ Molecule -​ Atom -​ Subatomic (smallest/simplest) ​ Organ Systems -​ Organs: Tissues that are further organized to perform specific functions -​ Animal organ systems Organ system Organ(s) Function Integumentary Hair, skin, nails -​ Covers and system protects body -​ Site of many sensory receptors Skeletal system Cartilage, bones, -​ Supports joints and protects the body -​ Enables movement (with muscular system) Muscular system Skeletal muscles, -​ Enables tendons movement (with skeletal system) -​ Helps maintain body temperature Nervous system Brain, spinal cord, -​ Detects and nerves processes sensory information -​ Coordinate responses  and activities -​ Controls body functions Endocrine system Pituitary gland, -​ Controls thyroid glan, growth and pancreas, adrenal development glands, testes, -​ Controls ovaries metabolism Cardiovascular Heart, blood -​ Delivers system vessels oxygen and nutrients to tissues -​ Equalizes temperature in the body Lymphatic system Thymus, lymph -​ Elimination nodes, spleen, of wastes lymphatic vessels, -​ Returns white blood cells fluid to blood -​ Defends against pathogens Respiratory Nose, mouth, -​ Removes system trachea, lungs, carbon bronchi, dioxide from bronchioles, the body alveoli, diaphragm -​ Delivers  oxygen to blood Digestive system Mouth, esophagus, -​ Ingestion stomach, -​ Digestion pancreas, gall -​ Absorption bladder, liver, gall of nutrients bladder, large -​ Elimination intestine, small of solid intestine, rectum wastes Urinary/excretor Kidneys, urinary -​ Controls y system bladder water balance in the body -​ Removes wastes from blood and excretes them Male reproductive Epididymis, testes -​ Produces sex system hormones and gametes -​ Delivers gametes to female Female Mammary glands, -​ Produces sex reproductive ovaries, uterus hormones system and gametes -​ Supports embryo/fetu s until birth  -​ Produces milk for infant -​ The body systems function in a way to maintain homeostasis -​ Homeostasis: “steady state”, means there is an acceptable range of physical and chemical conditions allowing the body cells, tissues, and organs to operate efficiently -​ How organ systems work together during movement: -​ Integumentary system and Circulatory system -​ In the heat, the blood vessels dilate so that excess heat can be released to the environment. Sweat is also produced to cool the body down -​ Circulatory system, Respiratory system, Muscular system, and Digestive system -​ When there is movement, the muscles use oxygen and glucose and produce carbon dioxide. -​ Heart rate increases to bring more oxygen-rich blood to the muscles and to remove carbon dioxide -​ Rate of breathing increases -​ Stored glucose from the liver enters the bloodstream to be given to the muscles for energy  -​ Skeletal system and Integumentary system -​ Calcium is essential for healthy bones -​ Vitamin D is absorbed by the skin, which helps the body absorb calcium -​ Nervous system and Cardiovascular system -​ Stimulates an increase in heart rate -​ Reduces the blood flow of tissues that are not needed in the movement -​ Plant organ systems -​ Vascular plants have two organ systems -​ Shoot system -​ Above ground -​ Stems provide structural support and bear the reproductive structures -​ Leaves perform photosynthesis -​ Organs: -​ Leaves: Cuticle -​ Waxy layer on -​ Limits the top of the amount of water epidermis that evaporates from the leaf’s surface in hot and dry environments Epidermis -​ Upper surface -​ Protection of a leaf Palisade tissue -​ Below the upper -​ Performs most epidermis of the  -​ Arranged photosynthesis packed and -​ Packed with vertically to chloroplasts and meet the Sun’s mitochondria rays head on Spongy mesophyll -​ Contains cells -​ Creates a loosely formed network with with lots of open spaces open spaces that contains gases needed/produce d by photosynthesis -​ Water vapour, oxygen, carbon dioxide Vascular bundle -​ At the center of -​ Xylem (on the the leaf top) -​ Contains xylem -​ Phloem (on the and phloem bottom) tissue Lower epidermis -​ Lower surface -​ Exchange of of the leaf gases between -​ Contains guard the leaf and the cells and outside stomates environment -​ Stomates -​ Allows for  carbon dioxide to enter and oxygen and water vapour to exit -​ Guard cells -​ Change their shape to control the opening and closing of the stomates -​ Transpiration: the evaporation of water through the stomata in the leaves -​ Stem: -​ 2 main functions: -​ Physical support -​ Transportation of sap -​ Contains most of a plant’s xylem and phloem tissue -​ Flower: -​ Does not take part in maintenance of the plant, only reproduction  -​ Root system/Root organ -​ Below ground -​ Roots anchor the plant -​ Roots absorb water and minerals required from the soil -​ Some roots also act as a plant’s storage area (e.g. carrot, beet) Unit 2 – Chemistry ​ Ionic and Covalent compounds ○​ Properties -​ Ionic compound properties -​ Formed by a cation and anion -​ Strong bond -​ Most are solid crystals in room temperature -​ High melting and boiling points -​ Hard and brittle -​ Good conductors of electricity -​ Will dissolve in a solution -​ Covalent compound properties -​ Formed by two or more nonmetals chemically combined -​ Elements share the electrons -​ Solid covalent compounds tend to be soft -​ Low melting and boiling points -​ Some dissolve in water easily -​ Poor conductors of electricity ○​ Use BR & Lewis diagrams to illustrate how atoms form ionic or covalent compounds  ​ Nomenclature (naming and writing formula) ○​ Ionic compounds- metal (cation) and nonmetal (anion) (use Roman numeral system only) ○​ Covalent compounds (non-metal and nonmetal – use the PREFIX system) ○​ Polyatomic compounds (*the list will be provided to you on the exam) ​ Chemical Equations ○​ Law of Conservation of Mass ○​ Write a balanced chemical equation given a word equation/skeleton equation ​ Chemical Reactions ○​ Evidence: chemical changes ○​ Types: Synthesis, decomposition, single displacement, double displacement, combustion ○​ Predict the products of a chemical reaction based on the reactants ○​ Factors affecting the rate of reactions ​ Acids and Bases ○​ Examples of common acids and bases (names and chemical formulae) ○​ Properties (including pH scale) ○​ Use of acid/base indicators ○​ Neutralization reactions Unit 3 – Physics ​ Electromagnetic Spectrum and Waves ​ Production of Light  ○​ Incandescence, phosphorescence, fluorescence, chemiluminescence, bioluminescence, LED ​ Reflection in Mirrors (plane and curved) ○​ Laws of reflection ○​ Plane vs convex vs concave mirrors ○​ Draw ray diagram & locate image ○​ Describe characteristics of images (SALT) ○​ Calculations using mirror equations ​ Refraction of Light ○​ Phenomena related to refraction (rainbows, apparent depth) ○​ Critical angle & total internal reflection ○​ Refraction calculations (index of refraction, speed of light, angle of refraction, Snell’s Law ) ​ Formation of Images in Lenses ○​ Converging vs diverging lenses ○​ Draw ray diagram & locate image ○​ Describe characteristics of images (SALT) ○​ Calculations using thin lens equation ○​ Human eye – parts and function, problems (e.g. hyperopia, myopia) Unit 4 – Earth and Space Science ​ Weather vs. Climate ​ Solar Radiation ○​ Albedo effect ○​ Absorption and reflection of radiation ​ Components of the Climate System ○​ Atmosphere, lithosphere, hydrosphere, biosphere ​ Energy transfer within climate system ○​ Radiation, conduction, convection ○​ In atmosphere and in oceans ​ Greenhouse Effect ○​ Greenhouse gases (carbon dioxide, methane, water vapour, nitrous oxide) and their sources ○​ Nature vs anthropogenic greenhouse effect ​ Evidence of Climate Change - examples ​ Effects of Climate Change ○​ On the atmosphere, hydrosphere, biosphere, societies, economy ○​ Positive feedback loop ​ Give examples ​ Climate Actions - what can be done to minimize effects of climate change