1. Life Science Review of Grade 6 Science

2. Classification of Organisms Taxonomy – the science of describing, classifying, and naming living things Carolus Linnaeus – the Swedish scientist who founded modern taxonomy

3. Classification System Kingdom (most general way to group organisms) Phylum Class Order Family Genus Species (most specific way to group organisms)

4. The Five-Kingdom Classification System – Monera Protista Fungi Plantae Animalia

5. Monera – Eubacteria (modern bacteria) & Archaebacteria (ancient bacteria) include bacteria and blue-green algae have no nuclei oldest & most numerous organisms on Earth

6. Protista include amoebas and euglenas single cells and microscopic have nuclei but lack any specialized tissues and organs commonly called protozoa

7. Fungi includes mushrooms, yeasts, and molds yeasts are unicellular, but the rest are multicellular decompose other organisms and are important to maintain a healthy ecosystem

8. Plantae includes mosses, ferns, flowers, and trees (multicellular organisms) most red, brown, and green algae (single- celled organisms) can make their own food by photosynthesis cannot move about freely

9. Animalia includes sponges, jellyfish, worms, shellfish, starfish, insects, fish, amphibians, reptiles, birds, mammals, and humans multicellular organisms get energy by eating other organisms are able to move about freely

10. Key words – invertebrate – animal without a backbone vertebrate – animal with a backbone

11. Structure and Function of Cells All organisms are made up of cells. Cells are the building blocks of life. Key words – unicellular – just one cell multicellular – many cells organelles – tiny structures in cells

12. Cell Organelles and their Functions cell membraneplant & animala semi permeable membrane that controls movement of molecules into and out of the cell nucleusplant & animalthe control center of the cell; contains chromosomes that carry the genes nuclear membrane plant & animala semi permeable membrane; encloses and protects the nucleus vacuolesplant & animalstorage sac that contains fluids, pigments, and other substances mitochondriaplant & animalthe powerhouse of the cell; releases energy to support all cell activities endoplasmic reticulum plant & animalsystem of tubules inside the cytoplasm for transport of materials cytoplasmplant & animalclear, thick fluid that holds all the organelles in a cell ribosomesplant & animalcontain enzymes that help make proteins chloroplastsplantcontain chlorophyll; where photosynthesis happens cell wallplantthe outer non-living cellulose structure that helps the cell keep its shape

15. Key Terms – Mitosis – the process of one cell dividing into two equal and identical cells; makes body cells Meiosis – the process of one cell divides two times to make sex cells with half the number of chromosomes of a body cell

16. Photosynthesis the process that plants use to capture energy from the sun and change it into food happens in the chloroplast chlorophyll, a green pigment in leaves, converts sunlight into food carbon dioxide, water, and sunlight energy is turned into sugar or food (glucose) and oxygen

17. Cellular respiration the process used by complex organisms, such as humans, to get energy from food happens in the mitochondrion food-sugar (glucose), oxygen is turned into carbon dioxide, water, and energy (ATP)

18. Reproduction and Heredity Reproduction – involves creating an entire organism

19. Two Methods of Reproduction – Asexual reproduction Sexual reproduction

20. Asexual reproduction – the offspring (young) has only one parent the offspring are clones of their single parent by mitosis (exact copies of the original cell) algae, bacteria, strawberries (runners), tubers (white potatoes), bulbs (tulips, onions), regeneration (planaria, starfish)

21. Sexual reproduction – the offspring has two parents the offspring form when a sperm and an egg join by a process called fertilization offspring have some of the traits of both parents and other traits not visible in the parents but nonetheless present offspring the offspring have genetic material from both parents

22. The nucleus - contains the organism’s genetic material contains 46 chromosomes (threadlike strands of DNA that carry the code or genes telling the traits the organisms will have)

23. Gametes – are the sex cells (eggs and sperm) contain 23 chromosome (half the number of chromosomes found in a body cell) made in the reproductive organs made by a process called meiosis (the number of chromosomes in the gamete is reduced by half)

24. Key Terms – dominant trait – the trait that appears in an offspring when two different genes are mixed recessive trait – the trait that does not appear when two different genes are mixed; for a recessive trait to be seen, two recessive genes must be present zygote – is the single cell formed when the egg and sperm unite; a fertilized egg embryo – is the name of the fertilized egg once it begins dividing by mitosis variation – differences in traits among individuals of a species

25. Systems of Living Things organized differentiated

26. Organization of Living Things cells tissues organs organ system organism

27. Organ Systems and their Functions Circulatorythe blood carries food, oxygen, and nutrients to all areas of the body Digestivebreaks down food and absorbs nutrients Endocrineuses chemical hormones to control other body systems Excretorygathers the wastes from the digestive, respiratory, and circulatory systems and discharges them from the body Immuneprotects us from disease - using the skin as a barrier to the outside world and using white blood cells and antibodies Muscularallows body movement, maintains posture, moves food Nervouscontrols and coordinates; carries nerve messages to and from the brain and spinal cord and rest of the body Reproductivetakes its signals from certain hormones to make sex cells to allow offspring to be produced Respiratorybrings oxygen in and removes carbon dioxide from body SkeletalProtects, supports, allows movement, makes blood cells, and stores minerals

28. Evolution and Biodiversity evolution – the process in which inherited characteristics within a population change over generations such that new species sometimes arise heredity – your characteristics that make up your physical body are handed down to your through the genetic material from your ancestors variation – differences in traits among individuals of a species adaptations – a characteristic or trait that improves an individual’s ability to survive and reproduce natural selection or survival of the fittest – the most fit organisms will survive and reproduce and pass their good traits to their offspring

29. Organisms and the Environment ecology – the study of the relationship of living things to the environment ecosystem – the living community of organisms and their nonliving environment food chain – a way of showing the order in which food energy passes from one organism to another food web – two or more food chains niche – the job or role an organism plays competition – when organisms struggle with one another to get the things they need to survive

30. Key Terms prey – the animal that is eaten predator – an animal that eats other animals parasite – an organism that lives off another organism host – the organism that provides a home for another organism socialization – when a species live together in groups to care and protect their young; primates, whales cooperation – when organisms work together; wolves, lions, whales

31. Symbiosis organisms from different species work together in groups and form partnerships that help the organisms involved

32. Three types of Symbiosis: mutualism – a form of symbiosis in which both organisms benefit commensalism – a form of symbiosis in which one organism benefits and the other is not harmed parasitism – a form of symbiosis in which one organism benefits and the other is harmed

33. Food Levels Producers Consumers Decomposers These food levels are used to show how far an organism is from the primary source of all food energy, the Sun. The closer an organism’s food source is to the Sun, the more numerous the organism.

34. Producers make their own food all green plants, phytoplankton (microorganisms in the ocean), algae

35. Consumers – eat other organisms primary consumers (herbivores) - eat only plants or parts of plants secondary consumers (carnivores) – eat herbivores or other carnivores omnivores – (primary & secondary consumers) - eat both plant & animals

36. Decomposers break down dead organisms recycle nutrients bacteria, earthworms, and fungi

37. Changes in Ecosystems over Time abiotic – nonliving factors in the environment biotic factors – living factors in the environment biome – a large area of land that has the same climate biodiversity – the variety in the types of organisms that live in an area catastrophic disturbance – unexpected events such as volcanic eruption, forest fires

38. Key Terms eutrophication – when extra nutrients get into a river, lake, or bay, they cause unusual algae growth. When too many aquatic organisms, such as algae, grow in a body of water, they deplete the level of oxygen in the water so that other organisms cannot live phototropism – the tendency of plants to bend or lean toward light in order to get the most energy from photosynthesis succession – a series of changes in a living community climax community – a stable community at the end of succession