7 th Grade Review

1. 7th Grade Review

2. Scientists to Know…. • Zacharias Janssen (1590) –put two magnifying glasses in a tube. • Anton van Leewenhoek (1600’s) created simple microscope using glass bead for lens. • Robert Hooke (1665) – looked at cork through microscope and called the “empty boxes” cells. • Matthias Schleiden (1839) – said all plants are made of plant cells. • Theodor Schwann (1839) – said all animals are made of animal cells. • Rudolph Virchow (1856) – said that older cells form new cells

3. Microscopes

4. Cells • Cells perform numerous functions: respiration, waste removal, growth, irritability, and reproduction. • Cell theory: a. All organisms are made of cells b. Cells are the basic unit of life. c. Cells come from other cells Onion cells

5. Cells to Systems…… • Organelles form cells, cells form tissues, tissues form organs, and organs form systems. • Ex: nervous system; respiratory system; etc……

6. Cell Review

7. Differences • Plant cells have chloroplasts that hold chlorophyll giving them their green color; cell walls, and larger vacuoles to store food. • Animal cells have centrioles.

8. Cell Parts and Their Functions… • Cell membrane – decides what comes in or out. • Nucleus – directs all activities. • Cytoplasm – gel- like material inside the cell. • Endoplasmic reticulum - moves things within the cell (highway system). • Golgi bodies – packages materials to be moved. • Mitochondria –produces energy.

9. Organelles Continued…. • Lysosomes –destroy waste • Ribosomes – make protein • Chloroplasts - turn light into food • Cell wall –protects the cell. • Vacuoles- storage units for food, water, and waste.

10. Mind Map (can you explain the meaning behind each picture)? cell membrane golgi bodies ribosomes lysosomes mitochondria cell wall vacuoles nucleus cytoplasm ER

11. Cell Tour

12. Plant Cell

13. Animal Cell

14. Cell types • Prokaryotic: simple in structure with no recognizable organelles. • Eukaryotic: most plants and all animals. Larger and have developed organelles.

15. Organ Systems • Digestive: breaks down food in to useable molecules • Circulatory: transports nutrients, water, and oxygen throughout body. • Respiratory: brings oxygen to body and releases carbon dioxide. • Excretory: removes waste and excess water.

16. Cell Processes • Diffusion – moves molecules from where there are many to where there are few (from high to low concentration). • Osmosis – the diffusion of water through a cell membrane. • Cells strive to maintain equilibrium.

17. Mitosis • Mitosis- the nucleus of a cell divides and creates two identical daughter cells in a series of phases: prophase, metaphase, anaphase, and telophase. • Asexual repoduction, single division, occurs in all body cells

18. Meiosis • Sexual reproduction with two cellular divisions resulting in four daughter cells with exactly half the number of chromosomes. • Occurs in organs. • Goes through metaphase, anaphase, prophase and anaphase.

19. Terminology to Know… • Unicellular - made up of only one cell. • Multi-cellular -made up of many cells. • Active transport – movement through cell that requires energy • Passive transport – movement that does not require energy. • Complex organisms need more cells. Paramecium

20. More Vocab • Life cycle – process of being born, growing, aging and dying is called. • Homeostasis - to maintain internal stability Example: normal body temp. • Spontaneous Generation -thought that living animals can form without descent from similar organisms. Example: idea that fleas could arise from dust, or that maggots could arise from dead flesh.

21. Animal/Plant Grouping • Biggest (most complex) to smallest (least complex) – Kingdom, Phylum, Class, Order, Family, Genus, and Species. • Species – share common characteristics, can mate, and have fertile offspring. • Ex: lion and tiger have ligers that are infertile (not a species) but a dog and wolf have pups that are fertile (are a species)

22. Populations • Populations (all the same animal) compete for basic resources, mates, and territories. • Must cooperate with each other to meet needs. • Have social order to ensure that labor and resources are shared. • Every organism fills a specific niche (job or role) in its community.

23. Populations and Niches

24. Symbiotic Relationships • Mutualism - both organisms benefit. Ex: clown fish and sea anemone. • Commensalism - one benefits and the other is unaffected. Ex: flies on a horse • Parasitism - one benefits and one is harmed. Ex: dog and flea

25. Clown Fish and Anemone

26. Living Space • Ecosystems include forests, the ocean, tidal pool, ponds, etc… • Ecosystems are living communities within a biome. • Biome is defined by climate range (temp and precipitation rates) and how well the organisms have adapted in that area. • Biomes are made up of ecosystems.

27. Biomes and Succession

28. Biomes and Succession

29. Organisms… • Organisms exist as a member of their population. * Organisms adapt to abiotic (non-living) and biotic (living) factors in their home.

30. Rescuing Animals from Poachers

31. Vocab to know… • Phototropism – when plants grow toward their food source. (move toward the sun) • Hibernation – animal response to cold conditions with a period of lowered metabolism. • Dormancy –response to adverse conditions with a period of low or suspended metabolism. (trees/plants do this)

32. Even More • Eutrophication – excess nutrients in water causing algae blooms. • Ectotherm: where body heat is regulated to match surroundings. AKA: cold blooded • Endotherm: regulates body heat within the body. AKA: warm blooded.

33. Genetics • DNA is a double helix molecule. • It includes four components that form a chemical code. • Chromosomes are strands of DNA. • Genes are sections of chromosomes that carry the code for a specific trait. • The basic laws of Mendelian genetics explains the transmission of some traits that can be inherited from generation to generation.

34. DNA and Criminal Investigation

35. More on Genetics… • Genetic engineering is when the genetic code is manipulated by man to get a desired product . • There are practical applications in medicine, agriculture, and biology. • Evolutionary processes include mutations, adaptations, natural selection, and extinction. Ex. Using Miracle Grow…

36. Evolutionary Processes • Adaptation – a change that increases chance of survival. • Mutation – a change that does not help the organism to survive. (sometimes harmful) • The evidence for evolution is from the fossil record, radioactive dating, genetic information, distribution of animals, and similarities within species. • Heterozygous gene (hybrid) – the genes in the genotype are different. Ex. (Bb) * Homozygous gene (purebred) – the genes in the genotype are the same. Ex. (bb, BB)

37. Genetics

38. Life Processes • All organisms need food, water, air, shelter, energy, and space to survive. • A food chain shows relationships between living organisms. • A food web is two/more food chains hooked together. • A pyramid shows relative amounts of energy available at each level. • Decomposers – organisms that break down other organisms. Ex. Bacteria.

39. More on life… • Producers (autotroph) bottom of any web, chain, or pyramid and make their own food. • Consumers (heterotrophs) –eat other living things. • 1st level consumer– herbivores (eat plants and algae) • 2nd level consumer –carnivores, eat the herbivores. • 3rd level consumer – they are at the top of the food chain.

40. Vertical Farms…the future?

41. Life Processes • All organisms need food, water, air, shelter, energy, and space to survive. • A food chain shows relationships between living organisms. • A food web is two/more food chains hooked together. • A pyramid shows relative amounts of energy available at each level. • Decomposers – organisms that break down other organisms. Ex. Bacteria.

42. More on life… • Producers (autotroph) bottom of any web, chain, or pyramid and make their own food. • Consumers (heterotrophs) –eat other living things. • 1st level consumer– herbivores (eat plants and algae) • 2nd level consumer –carnivores, eat the herbivores. • 3rd level consumer – they are at the top of the food chain.

43. Vertical Farms…the future?

44. Photosynthesis Cycle

45. More facts… • Ammonia is given off by dead plants and animals. • Predators kill and eat other animals. • Prey are the hunted. • Omnivores eat animals and plants. • Herbivores eat only plants. • Carnivores eat only animals. • Scavengers feed off of dead animals.

46. Nocturnal Versus Diurnal • Nocturnal animals are awake during the night and sleep during the day. • Diurnal animals are awake during the day and sleep during the night. Nocturnal Animals

47. Finishing it all up… • Extinction is when a species dies out. • Natural Selection – “only the strong survive”…is when nature decides who lives and who dies. • Biodiversity – means many different forms of living creatures in one area. • Ex. The ocean and the rain forest are extremely biodiverse.

48. Just for fun!