7 characteristics of life: 1)all living things are highly organized entities composed of 1 or more cells 2)use energy for their metabolic activities 3)respond to environmental stimuli 4)regulate internal environment to maintain relatively constanst internal conditions (homeostasis) 5)grow and develop 6)pass genetic material through reproduction 7) adapt to their environment through evolution Levels of organization: cell (human blood cell), tissue (human skin tissue), organ and organ system (stomach and intestine make up the human digestive system), organism-population-community (forest, each pine cone is an organism, all the pines is a population, living things in the forest is a community) ecosystem, biosphere (all ecosystems on earth) Growth: in body size, cell # and or size increases. Development: change in form over time. Asexual: involves one parent, offspring are genetically identical. Sexual: involves 2 parents, offsping is a mix between both parents dna. Species richness: describes de number of different species present in an area. Species evenness: describes the relative abundance of the different species in an area (similar abundace=more evenness). Known # of species: 1.8 million. Total # of species: 10-100 mil/about 10,000 new species every year. Group with most species: insects. Megadiversity spots: spots that house the largest indices of biodiversity, including a large number of endemic species. Tropical rain forest: the hot and wet climate provide ideal conditions fro many plant and animal species to thrive, nutrients are rapidly recycled sppeding up plant growth, geographic location and amount of precipitation, 50% of all species. Prokaryotes and eukaryotes: eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not, the nucleus is where eukaryotes store their genetic info, while in proaryotes dna is bundled together in the nucleoid region, but its not stored within a membrane-bound nucleus. The nucleus is only one of many membrane-bound organelles in eukaryotes. prokaryotes have no membrane-bound organelles. eukaryote dns cosists of multiple molecules of double stranded linear dna, while prokaryotes is double-stranded and circular. All cells: plasma membrane:  membrane found in all cells that separates the interior of the cell with the outside environment. Cytoplasm: gelatinous liquidd that fills the inside of a cell. DNA: complex molecule that contains all of the information necessary to build and maintain an organism. Ribosomes: particles consisting of rna and associated with proteins that function to synthesis proteins. All proka: cell membrane, ribosome, chromosome (dna), nucleoid region (weird shape region of the cell that contains most or all genetic material.  

Most proka: cell wall (protective layer  that surrounds some cells, gives them shape and rigidity). Some proka: capsule(sticky outermost layer) pili (short hair-like structures on the cell surface) flagellum (hairylike structure that works as an organelle of locomotion). All euka: cytoskeleton (made of filamentous proteins, provides mechanical support to the cell), Peroxisome (oxidative organelles), Mitochondrion (membrane-bound organelle, generates large quantities of energy), Rough endoplasmic reticulum (series of connected flattened sacs), Nucleus (houses the cells dna), Smooth ER (meshwork of fine dislike tubular membrane), Golgi apparatus (series of flattened stacked pouches), Lysosome (subcellular organelle). Plant cells: large central vacuole (surrounded by own membrane, contains water and dissolves substances), Tonoplast (membrane that surrounds the lv), Chloroplast ( part that carries out photosynthesis), Plasmodesmata (microscopic channels in the plant). Animal cell: centrioles (paired barrel-shaped organelles). Multinucleate cell: can be formed by cell fusion or by nuclear division not being followed by cytokinesis. Unicellular protist: flagella, cilia and pseudopods. 4 major types of tissue: Connective (supports other tissues and binds them together), Epithelial (provides a covering), Muscle (moves the skeleton), Nerve (electrical impulses for communication). Epithelial: Simple squamos epithelium (single layer of flat cells, small molecules need to pass quickly through membranes), Simple columnar epithelium (single layer of clolumnar cells attached to the basement membrane, lines most organs of the digestive tract), Transitional epithelium (stratified tissue made of multiple cell layers, strectch when its filled with fluid, unstrectched when fluis pressure is low), Simple cuboidal E (consists of single layer of cubiodal cells, prevention of water loss), Stratified squamous E (flattened cells in layers upon asal membrane). Connecive: Loose CT (most common, holds organs in place), Adipose (consists of lipid rich cells, store energy), Fibrous ct (parallel bundles of collagen fibers, shock absorption), Cartilage ( resilient smooth elastic tissue, like rubber, protects the end of long bones), Bone, blood. Muscular: skeletal (striated, multinucleate, voluntary), Cardiac (striated, multinucleate, involuntary), Smooth (non-striated, uninucleate, involuntary). Plants: Xylem (tracheids and vessel members-thick secondary cell wall, transports water and dissolved minerals), Phloem (sieve-tube members- primary cell walls, transports dissolved food).

Parenchyma: tissue that carries out primary function of organ. Stroma: supportive framework of an organ. Heart: endocardium (covers inner surface of the heart), myocardium (muscular wall of the heart, consists of cardiac muscles), Epicardium ( covers outersurface of the heart). Small intestine: 4 layers, mucosa, submucosa, musculari s and serosa. Leaf: Upper and lower  epidermis, mesophyll, veins. Respiratory: Lungs, diaphragm. DigestIve: Oral cavity, intestines and stomach. Excretory: kidneys, bladder, urethra. Reproductive: ovaries, uterus, vagina, testes, penis. Nervous: brain, spnal cord. Endocrine: pituitary, hypothalamus. Muscular: caridac and smooth muscle. Skeletal: bones, tendons, ligaments. Integumentary: skin, hair, nails. Circulatory: heart,blood vessels. Lymphatic: nodes, ducts