Biology Test PDF

Cell membrane: covers the cell - Gatekeeper to control the movement of mats in/out of the cell - Double layered - semi-permeable Cell wall: rigid mat- surrounds, protects and supports membrane (cellulose) Ribosomes: small protein structure- cell division - ANIMAL Chloroplast: organel...

Cell membrane: covers the cell - Gatekeeper to control the movement of mats in/out of the cell - Double layered - semi-permeable Cell wall: rigid mat- surrounds, protects and supports membrane (cellulose) Ribosomes: small protein structure- cell division - ANIMAL Chloroplast: organelle containing chlorophyll - photosynthesis - PLANT - Primary food factor - CO2+H2O→ C6H2O6+O2 DNA: threadlike structure- genetic/ hereditary info - Genetic code Cytoplasm: area of cell where nutrients=absorbed, transported & processed - # of organelles - Mostly water - Many chem reactions Cytoskeleton: network of protein fibers supporting cell shape anchors organelles - stretch/contract to move cell parts where needed ER: series of canals that carry mat through cell - 3D of branching tubes/pockets - Extends throughout cytoplasm - Fluid-filled 2 Types of ER: 1. Smooth ER a. No ribosomes attached b. Makes fats/lipids 2. Rough ER a. Ribosomes attached b. Helps make proteins Golgi apparatus: stores proteins until needed inside/outside the cell - collect/process mats to be removed from cell - make/secrete mucus(eg. intestine) Lysosomes: saclike structure formed by Golgi Apparatus - Proteins to break down large molecules/other cell parts - ANIMAL Mitochondria: tiny, oval-shaped organelles- provide cell energy from cellular respiration - Powerhouse Nucleolus: - sphere within the nucleus of some cells - Involved in making proteins… ribosomes Nucleus: control centre directing all cell activities - contains chromosomes and DNA Ribosome: organelle that builds proteins essential for cell growth & reproduction Vacuole: small membrane surrounded compartment that stores water, wastes other mats  - Larger in plant cells - When full of water, turgor pressure keeps the cells plump & firm Organelle functions: - intake of nutrients - movement - growth - exchange of gases - waste removal - reproduction Solute: sub that can be dissolved Solvent: dissolving solute (water) Solution: solvent & solute after combining ECF: surrounds all living cells Concentration: mass of solute dissolved in solvent Sa emi-permeable: membrane allowing some subs Passive Transport: movement of molecules (semi perm→ gradient) - 3 Types: Osmosis, simple diffusion, facilitated diffusion - Movement of molecules across a semipermeable membrane with protein - No ENERGY Active transport: movement of molecules across a semi-perm membrane against a concentration gradient with a protein - ENDOCYTOSIS - ENERGY REQUIRED Diffusion: solute molecules moving from an area with high concentration→ low  - Random motions - Equilibrium: even distribution of solute molecules Osmosis: diffusion of water→ semi permeable membrane - Permeable to solvents (WATER), not to large molecules - - High (water)--> low (water) water=solvent | glucose, starch, salt: solute Hypertonic Envrt: high (solute), low (water) Isotonic Envrt: (water)=(solute) Hypotonic Envrt: High (water), low (solute) Facilitative Diffusion: passive 2 Methods 1. Pore (Channel Protein): A protein that forms a tunnel in the membrane, allowing specific molecules or ions to pass through. 2. Carrier protein: A protein that binds to a molecule, changes shape, and transports it across the membrane. ​ Active Tranport 2 Methods  1. Against concentration gradient a. sodium - potassium pump 2. Endocytosis a. Bringing bulk chems into a cell (endo=inside) (exo=out) i. The pinched portion that breaks free from the cell membrane+ forms a vesicle in the cytoplasm Cell division: reproduction, reparation, growth of cells Asexual Reproduction: the process of producing offspring from 1 parent - Genetically identical offspring→ parent Eg. single-celled organisms, some multicellular organisms Sexual Reproduction: the process of producing offspring by fusion of sex cells from 2 Parnts - Offspring get HAlf genetic info from each parent Eg. most multicellular organisms The Cell Cycle: 2 major phases: interphase+mitosis 1. Interphase: series of phases allowing the cell to grow, duplicate DNA+prepare for mitosis 3 Parts: a. G1: cells grow (growth to undergo mitosis, if not daughter cells die) b. S: cells replicate Dna= 2 copies  c. G2: cells get ready to go through mitosis+ divide During interphase, cells carry out normal life functions 2. Mitosis: The cell divides and 1 cell=2 a. Purpose: 2 genetically identical daughter cells b. Considered the divisions of the genome/nucleus \ Cytokinesis: [physical separation of a cell into 2 daughter cells, following mitosis) MITOSIS AND CYTOKINESIS Interphase→ Prophase→ Metaphase → Anaphase→ Telophase→ Cytokinesis→ Interphase ****PMAT*** Prophase: chromatin in the nucleus condenses into thick coiled structures. Chromosomes - 2 copies of each chromosome - Each Chromosome contains 2 copies=sister chromatids (held by centromere) Metaphase: chromosomes line up the centre of the cell- moved by spindle fibres (attached to the centromere) Anaphase: centromere in the middle of chromosome breaks - Sister chromatids pulled to opposite sides/poles by spindle fibres Telophase: chromosomes/tids BEGIN to unwind to chromatin - The nuclear membrane begins to reform to make 2 new nuclei in the same parent cell Cytokinesis: not part of mitosis - Division of cytoplasm( 2 new daughter cells) - Animal cells: cytokinesis happens when the plasma membrane pinches until 2 cells=forms - In plant cells, a cell plate forms between 2 nuclei, separating them and creating two new cells Regeneration: process a body part=regrown - All cells in an organism contain the same DNA, but are not all alike - Cell specialization Stem cell: unspecialized cell- can form specialized cells exposed to proper environmental conditions/remain unspecialized and actiely dividing for long periods - Capable of becoming any tissue except the placenta Types: 1. Embryonic: able to undergo differentiation- found in embryos 2. Adult stem cells: stem cells that have underwent further specialization to the point where there’s limited ability to create a variety of cell types Differentiation Potency Definitions 1. Totipotent: Can become any cell, including placenta (forms a whole organism).(omnipotent) (from fusion of sperm+egg) 2. Pluripotent: Can become almost any body cell, but not placenta. (originate from inner masses cells within blastocyst) 3. Multipotent: Can become specific cells within a tissue (e.g., blood cells). Most stem cells for research from embryos are created by in vitro fertilization Most adult stem cells are involved in replacment of decayed tissue Maristematic Cells: plant stem cells - In growing tips of roots and stems+m layer of cambium - Constantly make new cells Organ: organized group of tissues jointed together to perform spec function Tissues: group of similar cells sharing special structure+function Animal organs 1. Epithelial Outer protective layor from epithelial tissue preventing dehydration, friction, bacteria+virus entrance and produces vitamin D when exposed to UV (essential for bone development) ○ Thin sheets of packed cells 2. Muscle:allow movement of body (long thin fibers containing specialized proteins capable of shrinking growing) Goosebumps, skeletal, smooth muscle, cardiac muscle Heart: supplies blood to body ○ 4 chambers: left and right atria+ left and right ventricles ○ Each side contains: atrium- receive blood from veins+pump to ventricles Ventricle- pump vlood to distant tissues Valves prevent blood from flowing backwards through system 3. Nervous: orivude sensory sensation (communication with brain) (thin cells with fine branches capable of conducting electricity) by neurons 4. Connective: Provide structure+support+insulation (hold tissues) Eg. blood/vessels, tendon (muscle→ bone), ligaments (bone→ bone), white/red blood cells Fat: insulation Dermi: inner layer of skin made of muscle, nervous and connective tissues Eg. skin protects us from cells damage and disease, insulates, releases waste and heat - Made of epidermis and dermis Respiratory System: nose, mouth, trachea, branchi, lungs Sugar+oxygen→ water+carbon dioxide+water * trachea separates into two branches (bronchi/ singular- bronchus) delivering air to lungs … each bronchus branches again and again (bronchioles) ending in tiny air sacks=aveoli that procide large surface area with thin cell walls - Some of the epithelial cells lining trachea+bronchi: produce mucus, have cilia, trap bacteria+dirt - Each alveolus surrounded by network capilaries (capillary network) for good bood supply - then oxygen+carbon only diffuse through two thin walls Lungs: pair of organs for respiration - Made of epithelial and connective tissue Inspirtion: to decrease air pressure in lungs 1. Diaphragm contracts+ moves downward (muscle) 2. External indercostal muscles contract and ribcage moves upward and out (increase in volume, decrease in pressure… air enters) Expiration: diaphragm and intercostal muscles relax. - decreasing volume, increasing pressure… air leaves Lungs move from lungs and blood by diffusion Digestive System Ingestion- taking in nutrients Digestion- breakdown of complex organic molecules into smaller components by physical/chemical means Absorption- taking up digested materials into the cells of the tract Egestion- removal of waste food mats from body Esophugus: muscular tube connecting mouth→ stomach - lining is a smooth muscle tissue (relax+ contract to swallow) Stomach: contracts+relax=break food (enzyms+hydrochloric acid - music protects the stomach lining from teh gastric juices Small intestine: most digestion done in the duodenum by secretions Large intestine: absorbs water and egestion: cellulose not digested(main component of feces) Waste builds up… large intestine voids waste The Circulatory System The “Pipes”: arteries (small and thin=arterioles), veins (venules), capillaries (from arterioles) Arteries - Large, thick-walled elastic vessels - Mostly oxegenated blood carried away from heart - Arteries shrink as aorta leaves the heart and decrease in diameter Capillaries - Thin hair-like structures, composed of single celled walls