Academic Science - Biology Notes

SNC2D Grade 10 Academic Science – Biology Notes SNC2D Biology Review Cell Theory: -all living things are made up of at least one or more cells and their products -the cell is the simplest unit that can carry out life processes -all cells come from other cells; they do not come from non-living matter Types of Cells: Prokaryotic: -single celled life forms -simple, primitive cells -no nucleus or organelles -ex. bacteria and archaea Eukaryotic -single or multicellular organisms -more complex and larger -do have nucleus and organelles -make up multicellular organisms like plants, fungi Limitations of Cell Size -as a cell grows bigger, the ratio or the area and volume decrease meaning the cell will not have enough room for nutrients -the cell membrane must be large enough to support the cell volume Organelles Cytoplasm -suspends organelles -fluid,jelly, liquid filling Cell Membrane -supports cell allows diffusions of unwanted substances -semi-permeable membrane Nucleus -spherical -contains all DNA and genetic info Mitochondria -powerhouse of cell -makes energy available for the cell -converts glucose to energy Endoplasmic Reticulum (ER) -3-D network of branching tubes that transport materials throughout the cell Golgi Body (Apparatus) -secretes mucus -collects and removes unwanted materials -has a stacked structure like pancake Vacuole -contains substances, isolates and removes waste, maintains internal fluid pressure Cell Wall (plants) -helps plant hold its shape -found outside the cell membrane Big Vacuole (plants) -full of water to keep stem and leaves firm -isolates and removes waste Chloroplast -absorbs light for photosynthesis to occur -has chlorophyll that gives green color Cell Division -growth (cells can’t grow too big) -repair reproduction (sexual and asexual) The Cell Cycle -eukaryotic cells grow and divide Interphase -cell performs normal functions -genetic material and DNA copied -DNA is doubled Mitosis: Prophase -long strands of DNA condense into compact form called chromosome -DNA shortened and thickened -nuclear membrane splits Mitosis: Metaphase -chromosomes line up in center of the cell, held by spindle fibers in order for mitosis to continue Mitosis: Anaphase -centromere splits and sister chromatids separate -appeared to be pulled apart -daughter chromosomes move to opposite ends of cell Mitosis: Telophase -new nuclear membrane forms -daughter chromosomes unwind and stretch out to become stringy masses -two nucleus Cytokinesis -final stage -organelles divide producing two identical daughter cells -in plants, plate develops between two cells called cell wall -in animals, cell membrane is pinched off in the center Chromatid: half of a chromosome Chromosome: organized bundle of DNA Chromatin: messy bundle of DNA Centromere: holds two chromatids together to create a chromosome Spindle Fibers: controls the movement of chromosomes, are scaffolding for the cell, doesn’t remain fixed, originate from the centrioles Cancer -cell division gone wrong -cells divide rapidly ignoring the body’s chemical reactions telling cell not to divide -changes in DNA that controls cell cycle Tumours Benign: -stays together, no serious effects to surrounding tissue -not cancerous Malignant: -interferes with functions of neighboring cells -cancerous Metastasis: -cancer cells break away from the tumor to settle into other parts of the body -cancerous Carcinogens -factors that can cause mutation (random change in DNA), leading to cancer -ex: tobacco smoke, radiation, viruses, chemicals in plastics -some cancers have a genetic/hereditary link Diagnosing Cancer Imaging -endoscopy (fiber optics) -x-ray (viewing bones and lungs) -ultrasound (sound waves for soft tissue view) -CT scan (x-rays at different angles) -MRI (radio waves and magnetic field generate images) Examining Cells -biopsy (sample of cells), viewed with microscope and genetic tests Treating Cancer Oncologist -specializing in cancer medicine Surgery -surgically removing cancerous cells Chemotherapy -using drugs to travel through body and target different cells -shrink or slow the growth of tumor -linked with surgery Radiation -cancer cells damaged easily by ionizing radiation -daughter cells are damaged and cannot divide further Biophotonics -using beams of light to detect cancer early and treat Hierarchy: organizational structure with more complex things at top and simpler things below it Organization of Organism 1. Cell ( ex. heart muscle cell) 2. Tissue ( collection of similar cells to perform particular but limited function. ex. heart muscle tissue) 3. Organ ( structure composed of different tissues to perform complex function. ex. heart) 4. Organ System ( system of one or more organs and structures that work together for a major body function. ex. digestion, circulatory) Tissues Epithelial -thin sheets of tightly packed cells that covers body surfaces and lines internal organs -protection from dehydration -ex. skin, lining of digestive system Connective -specialized tissue that provides support and protection for various parts of the body -support and insulation -ex. bones, tendons, blood Muscle -specialized tissue containing proteins that can contract and enable body movement -ex. heart, muscles that make bones move Nerve -specialized tissue that can conduct electrical signals from one part of the body to another -sensory, communication, coordination -ex. brain, nerves in sensory organs Cellular Differentiation: -process where a cell becomes specialized to perform specific function -an animal cell can differentiate into many cells called stem cells Stem Cells: an undifferentiated cell that can divide to form specialized cells Embryonic Stem Cells: can differentiate into any kind of cell Tissue Stem Cells: exist within specialized tissue, only able to differentiate into certain types of cells Skeleton -supports and protects body -provides structure -anchor for muscles -store calcium and minerals -bone marrow that produces red and white blood cells -allows movement -consists of bones, ligaments, cartilage Ligaments: connects bone to bone, holds bones together at joints Cartilage: dense connective tissue that provides support (ex. ear, nose) Tendon: less elastic than ligaments, connect muscle to bones Spine: central support for body, made of vertebrae Hands & Feet: bones with flexibility (hands: carpals, metacarpals, phalanges; feet: tarsals, metatarsals, phalanges) Ribs: protect heart and lungs Hips & Legs: for movement and posture (bones are tibia, fibula, femur, patella) Arms: flexibility (ulna, radius, humerus, clavicle, scapula) Types of Bones Long: l onger than wide (ex. femur, humerus) Short: about as long as wide (ex. carpals, tarsals) Flat: flat plates (ex. scapula, sternum) Irregular: non-uniform shape (ex. mandible, vertebrae) Sesamoid: embedded in tendon (patella) Axial Skeleton -skull bones, vertebrae, ribs, sternum Appendicular Skeleton -bones of pectoral girdle, pelvic girdle, upper and lower limbs Joints Hinge: flexion, extension (ex elbow/knee) Pivot: p ivot, turn, rotate, move (ex. top of neck) Ball and Socket: f lexion, internal/external rotation (ex. shoulder, hip) Saddle: f lexion, extension, adduction, abduction, circumduction (ex. thumb) Muscles -composed of muscle fibers arranged in bundles -proteins cause contraction -skeletal muscle: under voluntary control -smooth muscle: involuntary (ex. intestines) -cardiac muscle: located in heart -nerve impulses causes muscles to contract and move bones -muscles can pull but not push, WORK IN PAIRS Systems Digestive: system that digests food and excretes waste (mouth, esophagus, stomach, intestines, liver, pancreas, gall bladder) Circulatory: t ransports oxygen and nutrients throughout the body and carries away waste (heart, blood, blood vessels) Respiratory: p rovides oxygen for the body and allows for CO2 to leave (nose, mouth, bronchi, trachea, lungs) Musculoskeletal: supports body, supports delicate organs, allows movement (bones and skeletal muscle) Nervous: senses the environment and coordinates responses (brain, spinal cord, peripheral nerves) E n d o c r i n e : secretehormonescircul c u l a t o r y s y s t e m ( g l a n d s ) Urinary: eliminates waste and regulates blood and liquid in body (kidneys, ureters, bladder, urethra) Integumentary: protects body from damage (skin and its appendages like nails and hair) Reproductive: f or sexual reproduction (sex organs) Interactions of Systems Digestive and Circulatory -Without the circulatory system, only tissues next to the digestive tract would receive nutrients. The circulatory system provides transportation of nutrients throughout the body. The digestive system converts food into small molecules that pass through the walls of the digestive tract. ex. capillaries surround digestive tract to carry blood that absorbs the nutrients Musculoskeletal and Respiratory -skeletal muscle tissue uses oxygen and nutrients to move -every muscle contraction, the rate of cellular respiration increases -to fuel the active system, circulatory must deliver a constant supply of oxygen and nutrients with the respiratory system working together to remove CO2 waste SEXUAL REPRODUCTION -2 parents and a unique offspring -responsible for variation between individuals -meiosis -two haploid cells (sexcells/gametes) combine to reproduce a diploid cell (eventually becoming unique offspring) Diploid (2): c ell or organism with 2 sets of chromosomes, 1 from each parent (46 chromosomes) Haploid (1): c ell or organism (sex cells) has half the number of chromosomes (23 chromosomes) Gametes -haploid male/female sex cell -egg/sperm cell -produced through meiosis SEQUENCE OF SEXUAL REPRODUCTION 1. Meiosis between male and female produces haploid gametes (egg/sperm) in gonads (ovaries, testes) 2. Male gamete combines with female gamete 3. A z ygote (diploid cell formed by combination of two gametes) is produced then further developed into an e mbryo (multicellular diploid eukaryotic cell in earliest stages of development) 4. Embryo develops into a mature and unique offspring from mitosis and cell division. Development of Sperm 1. Hormonessignalspermtodevelopinthes eminiferoustubulesinthetestes . 2. Epididymis receives sperm and stores it for several days 3. Ejaculation causes sperm to forcefully expel from the tale of the epididymis into the vas deferrens 4. Seminalvesicles/p rostate: secretionsareaddedtosperm,spermbecomessemen 5. Semen passes through urethra and is ejaculated through the far end of the u rethra Development & Pathway of Egg 1. Egg (ovum) is released into the o vary (follicle) 2. Follicle matures and releases egg into fallopian tubes 3. If fertilized. egg (zygote) remains in fallopian tubes then develops into a cluster of cells, implanting in the u terus for development. Plants -multicellular organisms -eukaryotic (have nucleus and organelles) -immobile -autotrophic -can reproduce sexually and asexually -must exchange gasses, absorb water and nutrients to transport as food -do not need complex systems to hunt for their food Shoot System -system in flowering plant that is specialized to photosynthesize and reproduce -consists of: Leaf: main photosynthetic organ, organelles in leaf have chloroplasts for photosynthesis, have been adapted for protection, reproduction, and chloroplasts Stem: primary purpose is to support leaves and flowers; it also joins leaves and roots; transports sugar from leaves to roots; and carries water, minerals, and other nutrients from the roots to the leaves. Flower: Designed for sexual reproduction, can be either male or female, and is pollinated by insects, birds, and other flying creatures. Root System -system in flowering plant that anchors plant, absorbs water and minerals, stores food -water and nutrients are sent up to leaves through xylem Fibrous Roots (monocots) -adapted to increase surface area for absorption -shallow depth in soil -ex. grass, lilies Tap Roots (dicots) -adapted to anchor plants and for storage -grows deeper into the soil -ex. carrot, tree, dandelion Plant Tissues Dermal Tissue -forms outer layer of plant (epidermis) for protection -epidermal leaf cells produce waterproof cuticle which stops intruders -cuticle: layer of wax on the upper and lower surfaces of the leaf that blocks the diffusion of water and gasses Vascular Tissue -for circulation of minerals, nutrients, water 1. XYLEM -transports water and dissolved materials from the roots up to the leaves -elongated cells join to make tubes 2. PHLOEM -transports products of photosynthesis all around the plant -elongated cell like tubes remain alive at maturity Ground Tissue -the “filler” located between the dermal and vascular tissue -performs functions of photosynthesis, food and water storage, and structural support Periderm tissue: t issue on the surface of a plant that produces bark on stems and roots Epidermal tissue: thin layer of cells covering all non-woody surfaces of the plant Meristematic Cell: an undifferentiated plant cell that can differentiate to form specialized cells, similar to animal stem cells, ONLY PLANT CELL THAT UNDERGOES MITOSIS *purpose of cell division in cells: grow in size, shape, perform functions, have plants grow and reproduce through meiosis* Apical Meristem: undifferentiated cell at tips of plant’s shoots and roots; cells that divide and enable the plant to grow longer/taller and develop into specialized tissues Lateral Meristem: undifferentiated cell under the bark in the stems and roots of woody plants; cells that divide and enable the plant to grow wider and develop specialized tissues in the stem Tissues working together -stem, leaf, and flower all work together to do its main job of feeding itself (photosynthesis) Absorbing light and gasses –xyleminvasculartissuebringsthewatertomesophylltissuesofthele a f a n d t h e g u a r d c e l l s o f t h e stomata a llow for CO2 to enter -water and CO2 go through photosynthesis in the chloroplasts of the leaves -the glucose made from photosynthesis transfers to the vascular bundle/vein and into the phloem to send the food for the roots, meristem tissue, and fruit -g guard cells controlling s tomatal pore a re responsible for gas exchange -guard cells open and close to allow CO2 in when photosynthesis can occur and let O2 out Palisade Layer -layer of tall, closely packed cells containing chloroplasts -just below the upper surface of the leaf -type of ground tissue Spongy Mesophyll -under the palisade layer of the leaf -circulates air and exchange of gas -a region of loosely packed cells containing chloroplasts -in the middle of the leaf -type of ground tissue Guard Cells -one pair of special cells in the epidermis (epidermal tissue) -surrounds the stomata to let gas in Stromae (plural stomata) -an opening in the surface of a leaf that allows for exchange of gasses -surrounded by two guard cells Vegetative Reproduction -asexual reproduction (cloning) -process where a plant produces a genetically identical offspring from its roots or shoots -ex. strawberries sent long ‘runners’ that can grow into new roots using the meristems in the tips of these ‘runners’