Keystone Review

1. Keystone Review Genetics DNA

2. Homozygous—both alleles the same • Heterozygous—each allele different

3. Types of Inheritance Dominant One trait completely masks/dominants the other trait when it is expressed. Can be homozygous or heterozygous dominant

4. Types of Inheritance Recessive The recessive trait is seen when there are 2 copies present (homozygous recessive)

5. Types of Inheritance Codominance • Both traits are equally dominant • Both show up at the same time • Use two different letters • R for red and W for white • RR red • WW white • RW red and white 

6. Codominance Black Feathered Chicken White feathered chicken Checkered feather chicken (my favorite!)

7. Types of Inheritance--Incomplete Dominance • Neither trait is dominant. • The traits “blend” together to make a new color/trait. • Use letters with slashes • R for red and R’ for white • RR = red • R’R’ = white • RR’ = pink

8. Types of Inheritance Sex-linked • The trait is carried on the sex chromosome (x-chromosome) so the inheritance is different for males and females. • Males inherit one gene from mother on X chromosome and an unaffected Y from father. • Females inherit an X from their father and an X from their mother

9. Types of Inheritance Polygenic • Trait controlled by 2 or more genes and produces a range of outcomes (examples: skin color, eye color, hair color, height)

10. Types of InheritanceMultiple Alleles More than 2 forms of a gene control the trait.

11. Chromosomal Mutations • These mutations alter the composition or number of chromosomes in the organism. • Usually have severe consequences for the organism. • Usually occur during meiosis

12. Nondisjunction • Failure of homologous chromosomes to separate during meiosis I or II • Results in monosomies and trisomies

13. Translocation

14. Deletion

15. Duplication

17. Point (Gene) Mutations • Original DNA THE CAT ATE THE FAT RAT. • Silent Mutation (DNA changes but protein does not) THE CAT ATE THE FAT RAT • Nonsense Mutation (inserts a stop) THE CAT ATE THE. • Missense Mutation (changes the protein) THE CAR ATE THE FAT RAT. • Frameshift Mutation (changes every amino acid after) THE CCA TAT ETH EFA TRA T. THC ATA TET HEF ATR AT.

18. Frameshift Mutations

19. DNAProtein SynthesisGenetic Engineering

20. DNA REPLICATION Semi Conservative Replication

21. Translation Protein Synthesis Transcription Information from the DNA (in the nucleus) is copied in the form of messenger RNA. Copies only the information for the protein that needs to be made The mRNA then leaves the nucleus and travels to the ribosome. Decodes the information from the mRNA Occurs in the ribosome Needs tRNA and mRNA to make the protein correctly according to the directions that were specified in the original DNA Genetic code for each amino acid is the same in ALL organisms.

22. Codon Protein

24. Genetic engineering – the process of altering the genetic material of cells or organisms to allow them to make new substances or to change their traits.

25. Selective breeding – when humans select which organisms to breed to get a desirable trait (example – breed cows to get them to produce the most milk) This method used trail/error and was time consuming. Using genetic engineering we can now accurately get the desired results every time.

26. Genetic Engineering

28. Cloning – making a genetically identical copy of an organism

29. Gene therapy – attempting to treat a genetic defect in an organism by introducing a new gene for the missing/defective original gene

30. Medicine: • Create new medications (ex: human insulin made by bacteria, clotting factors for people with hemophilia) • Figure out how genes function during development – look for ways things go wrong • Look for cures for genetic diseases (cystic fibrosis – replace missing gene to help lessen symptoms) • Continuing to research cures for cancer, AIDS, hemophilia etc • Create new vaccines

31. Forensics: • Identify criminals • Identify human remains • Identify the parents of an individual • Trace human origins

32. Agriculture: • increase food supply by making crops more tolerant to environmental conditions • make plants resistant to herbicides, pests and certain diseases • improve nutritional value

33. Keystone Ecology Review

34. Levels of Organization • Ecosystem—biotic & abiotic • Community—all biotic factors • Pollution—only one group (species) of organisms

35. Comparing Biotic and Abiotic Factors Biotic—all living or once living organisms Abiotic—all non living factors

36. Food Chain in an Antarctic Ecosystem • A food chain shows ONE possible feeding pathway. • The arrow always goes into the mouth of the eater

37. Food Web in an Antarctic Ecosystem • A food web shows all possible feeding relationships in a ecosystem

38. Energy Transfer Through Trophic Levels • Only 10% of energy from each level is available to be passed on to the next level. • Most of it gets used or lost as heat. That’s why more organisms on bottom than top

39. Energy Pyramid

40. Symbiosis—close, long term relationship b/w to organisms (at least one benefits Parasitism, mutualism, commensalism

41. Parasitism The parasite benefits while the host is hurt

42. Mutualism • Both organisms benefit

43. Commensalism • One benefits while the other is neither hurt nor helped

44. Recycling Matter through the Ecosystem

45. Water Cycle • Key processes are • Evaporation • Transpiration • Precipitation

46. Carbon Cycle Photosynthesis & Respiration are the two main steps

48. Nitrogen Cycle • Nitrogen fixing bacteria change nitrogen gas into a useable form for nitrogen for plants (& then animals) • Denitrification puts nitrogen gas back into the atmosphere

49. Phosphorus Cycle Phosphorous moves from phosphate deposited in rocks , to the soil, to living organisms and finally to the ocean

50. Succession—gradual sequential regrowth of a community of a species in a area Two Types: Primary Secondary