LESSON 6 M U LT I C E L L U L A R O R G A N I Z AT I O N
LEVELS OF ORGANIZATION Multicellular organisms have five levels of cellular organization Cells-} Tissues-} Organs-} Organ System-} Organism
LEVELS OF ORGANIZATION Cells are the most basic unit of structure and function in an organism Tissues are similar cells working together to perform a specific function
LEVELS OF ORGANIZATION Organs are composed of different types of tissues that work together to perform a specific function Organ systems are composed of organs working together to serve a particular function An organism is made of many organ systems working together
ORGANIZATION IN PLANTS Plants have eukaryotic cells that are arranged into three major types of tissue: 1. Vascular tissue 2. Dermal tissue 3. Ground tissue
VASCULAR TISSUE transports materials to all parts of the plant Xylem transports water and nutrients from the roots up Phloem transports glucose from the leaves down
DERMAL TISSUE provides structural and protective support to the plant It makes up the outer layer of the plant It includes specialized cells that allow gases in and out
GROUND TISSUE makes up most of the plant includes cells that carry out photosynthesis also provides storage and support
IN PLANTS, ORGANS ARE OFTEN CALLED STRUCTURES Just like in animals, organs are tissues working together Flowers are reproductive structures Stems are support structures Leaves are structures for making glucose Roots, tubers, and rhizomes take in water and provide a place for storage.
THESE STRUCTURES ARE ORGANIZED INTO TWO ORGAN SYSTEMS: 1. The root systemunderground, organs work to absorb water and nutrients and provide stability 2. The shoot system- above ground, includes leaves, stems, and flowers.
ORGANIZATION IN ANIMALS Just like plants, animal cells are organized into tissues. There are four main types of animal tissues: 1. epithelial tissue 2. connective tissue 3. muscle tissue 4. nervous tissue
ANIMAL TISSUES Epithelial tissues: line organs and provide protection Connective tissues- hold other tissues and organs in place and include bones, blood, and cartilage
ANIMAL TISSUES 3. Muscle tissueprovides movement in the body 4. Nervous tissueis responsible for information transmission and processing
ANIMAL TISSUES Animal tissues make up organs, such as the heart, brain, and lungs Organs work together to form organ systems #respiratory system, digestive system, nervous system, etc.
CHANGE OVER TIME Even though there is great biodiversity, many living things share similar anatomical or structural similarities. Evolution is the idea that populations change over time. Individuals with traits that help them to survive are more likely to reproduce When they reproduce, those individuals are likely to pass those traits on to their offspring.
CHANGE OVER TIME Offspring then have a better chance at survival and will also be more likely to reproduce, thus passing on the traits to the next generation If this passing on of the trait continues, it can change the traits of an entire species over time.
CHANGE OVER TIME The beneficial traits that help organisms survive and reproduce are called adaptations. As the environment changes, certain traits that were helpful before may no longer be beneficial
CHANGE OVER TIME Fossil records allow scientists to investigate how traits have changed over time often show that ancient plants and animals had unique anatomical parts. show that that a fossilized organism has parts similar to that of a living organism records can help scientists understand how some species have evolved
DIFFERENT, BUT WITH SOME SIMILARITIES Organisms share a lot of traits even when they are different enough to be classified as a different species. Whales, frogs, horses, lions, humans, birds have similar arrangements of fore limb bones. Organisms that share more traits are likely more closely related
CLADOGRAMS Cladograms are a type of diagram that use a branching structure to display both ancestry and similar traits. the fewer the lines in between organisms, the more closely they are related
THE AMAZING BODY A characteristic of living things is that they respond to stimuli. When you get a cut, it triggers a series of important responses in your body.
THE AMAZING BODY This cut has broken the protective barrier between your internal organs and the outside world. The outer layer of skin is called the epidermis Its main job is to protect you from the outside world it is made of hardened cells these cells constantly regenerate A cut that only goes into the epidermis is not a big deal because these cells are easy to replace.
THE AMAZING BODY The dermis is a deeper layer of skin contains blood vessels and other cells and tissues that your skin uses A wound that injures the dermis will prompt different responses in your body When the dermis is punctured, the body responds in order to prevent infection and stop blood loss
HEMOSTASIS First stage of response is hemostasis hemo refers to blood and stasis means stability in Greek Hemostasis is your body trying to stabilize blood loss
THE AMAZING BODY A protein called fibrin is sent to the wounded area to make links on the skin that will clot the blood. Fibrin plugs the hole created by the wound it keeps blood from getting out and germs from getting in
THE AMAZING BODY your body also tries to stop blood loss by vasoconstriction vasoconstriction is when your body shrinks or constricts blood vessels so that less blood can flow to those areas
INFLAMMATION Next stage of response is inflammation Skin around the area turns red Your body is sending white blood cells (WBCs) to the area WBCs will eat any germ cells that have entered your body. To help more WBCs get to the wound more quickly, the body will open up blood vessels wider in a process called vasodilation.
REPAIRING THE TEAR The proliferative stage is to repair the tear in the skin Special cells called fibroblasts are sent to the area to make a special protein That protein will begin to connect the ends of the torn tissue
REMODELING STAGE New skin cells have been made to fill in the gap If a wound is deep enough, the skin may never reach its original appearance, causing a scar
GROWING BACK AN ARM? Not all animals respond to injury this way. Some are way more efficient and can even regenerate limbs Others are far more delicate than humans.