Chapter 10 – Multicellular Organisms 10-1 – How they meet needs 10-2 – Plants are producers 10-3 – Animals are consumers 10-4 – Fungi are decomposers

Chapter 10-1 – Meeting needs Multicellular organisms (mo’s) have cells that are specialized. In single-celled organisms, all functions are performed by each cell. MO’s life functions (getting energy/raw materials, waste removal, responding to changes in environ, reproducing) - done by specialized cells.

10-1 Levels of Organization MO’s cells must work together for an organism to survive. Specialized organization starts with the cells (ex. Skin, nerve, muscle are different) Cells of same type = tissue Different tissues working together to perform the same function = organ Organs have different functions

10-1 Organ Systems Organ systems have multiple organs working together (ex: nervous, respiratory, muscular, circulatory, digestive) to perform the same function & help organism survive Nervous = enables responses to changing conditions Muscular = movement & heat Respiratory = Oxygen in; CO2 out Circulatory = delivers oxy. & removes CO2. Digestive = breaks down food into useable form

10-1 MO’s have varied adaptations Adaptation– any inherited characteristic (shape, structure, behavior, etc) that increases an organism’s ability to survive & reproduce offspring that reproduce. Single celled organisms reproduce A- sexually (only 1 parent; offspring identical to parent)

10-1 Sexual Reproduction & Diversity Most MO’s reproduce sexually (2 parents needed; offspring’s DNA not identical to parents) Sexual Reproduction: Meiosis = cell division that produces male sperm and female egg cells which contain one copy of DNA instead of 2. Fertilization = sperm and egg cell unite & new cell has 2 sets of DNA male/female

10-1 Sexual Reproduction cont. Most multi-celled organisms reproduce sexually. Some do not example: “budding” in plants Differences in genetic material and in the environment produce differences in offspring. How well something grows depends on both genetics and environment.

10-1 Benefits & Drawbacks Organisms that reproduce asexually can reproduce more often, but lack lack genetic diversity within a group. MO’s that reproduce sexually reproduce less often, but have greater genetic diversity due to having 2 sets of DNA (half from each parent). So new combinations allow for greater diversity/adaptations in offspring.

10-2 Plants Are Producers

10-2 Plants Are Producers Plants capture energy from the sun. Energy from the sun cannot drive cell processes directly. Light energy must be changed into chemical energy (photosynthesis). Chemical energy is the form of energy that all organisms need to carry out life.

10-2 Producing Sugars Photosynthesis = process by which sunlight energy is transformed into chemical energy Raw Materials: Water and CO2 are used in the production of sugars By-Products of Photosyn = O2 (oxygen) + sugar and/or starch Most photosynthesis takes place in the leaves; (autotroph=self feeder) Roots, Stems, Leaves, etc.=organ sys.

10-2 Storing & Releasing Energy Algae, bacteria, protists can also use photosynthesis Plants are MO’s and can store energy, where simple 1-celled organisms cannot. Plants store excess sugars as starches & use them for growth. Starches can store chemical energy Cellular respiration is the process by which a cell uses oxy. To break down sugars & release energy

10-2 – Plants are adapted Plants are adapted to different environments. (Different leaves, stems, roots, etc) Coniferous = cone bearing (ex.pine) Deciduous = trees that lose leaves in different seasons (oak, maple) Other adaptations: how quickly they flower & seed themselves

10-2 Respond to Environ. Stimulus = something that produces a response from an organism Examples: gravity=roots grow down; sunlight = leaves turn towards it; flowers open/close Touch = plant touches another object and plants tendrils wrap around that object.

10-2 Respond to Environ. Hormone = a chemical substance produced in one part of organism that travels to another part of the organism where it produces a reaction or response. Auxin = a hormone that stimulates cell growth in the tip of a plants stem (or root). Auxins on the dark side of a plant contain more auxins (which avoid light) than cells on the lighted side of a plant.

10-2 Seasonal Changes Shorter period of sunlight (fall/winter) affect photosynthesis time. Seasonal changes trigger plant “dormancy” when plants stop growing to conserve energy Plants also may change leaf colors & drop leaves due to seasons. Seasons also affect seed production

10-3 Animals Are Consumers

10-3 Food = Energy Consumer = an organism that needs to get energy from another organism. Animals are heterotrophs (organisms that feed on or consume other organisms). Animals seek food by grazing, hunting, etc

10-3 What Animals Eat Herbivores = organisms that feed on plants or algae. Examples: Cows, ducks Carnivores = feed on other animals Example: Lions, wolves Omnivores = feed on both plants and animals. Bears, Mice

10-3 Processing Food f/Energy Energy is stored in complex carbon compounds which must be broken down into simpler compounds. Digestion is the process that breaks down food into useable size using both physical and chemical activity. Food enters mouth & as it moves through the system, it’s broken down, releasing energy/nutrients, and waste is expelled at the other end of the digestive system.

10-3 Releasing & Storing Energy Animals get energy from sugars and other carbon compounds the same way plants do (cellular respiration). Animals/plants both take H20 through their digestive systems Animals have varied structures for getting O2 (gills, spiracles, lungs, etc). Animals must store food in tissues/organs for later use.

10-3 Animal Interactions Animal bodies have many adaptations (systems) that allow it to process food (digestive, respiratory, circulatory). Other systems allow interaction w/environment (muscular, skeletal, nervous, etc.) Behavior = an observable response to a stimulus (light, sound, odor, temperature.sight, etc)

10-3 Three Behavior Categories Individual Behaviors Ex: Often involve meeting basic needs (food, water, shelter, sleep, grooming) Animal to animal of same species or “social behaviors” Ex: Parent to offspring; attracting mates; group hunting (wolves); bees in hive Animal to animal of different species Ex: Predator-Prey behaviors; or mutualism (tickbirds removing ticks from impala)

10-3 Animals Seasonal responses Animals respond to seasonal changes in their environment (drought, heat, cold) Migration – the movement of animals to a different region in response to an environmental change. (Ex: birds, butterflies, wildebeast, elephants, etc.) Hibernation – a sleeplike state that lasts for an extended time period. (Ex. Frogs, turtles, fish, bears, etc.)

10-4 Fungi Fungi Are Decomposers

10-4 Fungi Absorb Materials Most fungi are decomposers that break down complex carbon compounds and use them for energy and raw materials. They absorb nutrients and leave behind simpler compounds Fungi are heterotrophs

10-4 Characteristics of Fungi Yeast = unicellular fungi; All other fungi are MO’s (multi-cellular). Organization: Cells have nucleus, thick cell walls Do not have: specialized tissues or organs. Do have: reproductive body & hyphae (thread-like structures, one cell thick). Mycellum = a mass of hyphae

10-4 Reproduction of Fungi Fungi reproduce with spores which can be produced either asexually or sexually. A spore is a single reproductive cell that is capable of growing a new organism. Spores are air-borne, spread by wind, and can survive many years. Fungi can also reproduce asexually by breaking off hyphae & regrowing a new fungi; they can also “bud” (yeast)

10-4 What are Fungi? Mushrooms – The outer part of a mushroom is only part of the fungus. The mushroom’s hyphae/mycellum is underground Molds – Spore producing part of another type of fungus. Yeasts = Single celled fungi; need moisture, heat

10-4 Helpful? Or Harmful? Fungi are Earth’s main decomposers. Helpful: Penicillin is an antibiotic that helps treat disease and make cheese (brie, Camembert, and blue cheese). Penicillin keeps bacteria from forming new cell walls during reproduction so bacteria cells break open and die. Aspergillis fungus used to make soy sauce. Trichoderma is used in making stone- washed jeans.

10-4 Harmful Fungus Many molds cause disease. (Athlete’s food; Dutch Elm Disease; Powdery Mildew) 1845 Irish potato famine was caused by a potato fungus which produced toxins, disease & famine which killed 4 million people. Lichen = fungi that live together with a single-celled algae forming a sort of “sandwich” around the algae.