1. Biology
Exam Review

2. Biology
The study of life

3. Characteristics of Living Organisms
Made of cell(s)
Displays organization
Grows and develops
Reproduces
Responds to stimuli
Requires energy
Maintains homeostasis
Adaptations evolve over time

4. Scientific Method Ask a question or make an observation
Form a hypothesis
Conduct an experiment
Collect and analyze data
Draw a conclusion

5. Ecology
The study of how organisms interact with one another and with the nonliving part of the environment

6. Levels of Organization
Organism
Population
Community
Ecosystem
Biome
Biosphere

7. Symbiotic Relationships
Parasitism – one species benefits the other is harmed in some way
Mutualism – both species benefit
Commensalism – one species benefits the other is neither harmed nor helped

8. Autotrophs or Producers
Collect energy from sunlight to produce food

9. Heterotrophs
These organisms get energy by consuming other organisms

10. What do organisms eat?
Herbivores eat producers.
Carnivores prey on herbivores.
Omnivores eat both plants and animals

11. Food Chain and Food Web
A food chain is a simple model that shows how energy flows through an ecosystem.
A food web is an interconnected group of food chains.

12. Biogeochemical Cycle
A cycle that involves moving a substance (water, carbon, nitrogen…) from the living environment to the nonliving and back again

13. Density-dependent vs. Density-independent factors
Density-dependent factors are factors that depend on the number of members in a population.
Density-independent factors are factors that do not depend on the number of members in a population.

14. Macromolecules
Carbohydrates – monosaccaharides
Proteins – amino acids
Nucleic acids – nucleotides
Lipids – glycerol and 3 fatty acids

15. Cell
The basic unit of life

16. Cell Theory All living organisms are composed of one or more cells
Cells are the basic unit of structure and organization of all living organisms
Cells arise only from preexisting cells

17. Prokaryotic vs. Eukaryotic
Prokaryotic cells lack a nucleus and other membrane-bound organelles.
Eukaryotic cells have a nucleus and other membrane-bound organelles.

18. Cell Membrane
Selectively permeable
Made of a phospholipid bilayer
Fluid mosaic model – the phospholipids create a “sea” in which the other molecules can float

19. Cytoplasm
Semifluid material in which organelles are found in a eukaryotic cell
This is where all prokaryotic cell activities occur

20. Nucleus
Contains the majority of the cell’s DNA
Surrounded by nuclear envelope
Where chromosomes are located

21. Ribosomes
The organelle that helps manufacture proteins
Made by the nucleolus
Can be free-floating or attached to the ER

22. Endoplasmic reticulum (ER)
Membrane system of folded sacs and interconnected channels
Rough ER or Smooth ER
Synthesizes proteins, lipids and carbohydrates

23. Lysosome
Digestive body of the cell

24. Centrioles
Found in animal cells and are used for structure during cell division

25. Mitochondria
Converts glucose into ATP
Site of cellular respiration
Referred to as “powerhouses” of cell

26. Chloroplasts
Found in plant cells but not animal cells
Site of photosynthesis

27. Cell Wall
Thick, rigid, mesh of fibers that provides protection and support to cells
Found in plants but not animals

28. Diffusion and Osmosis
When a substance moves from an area of high concentration to low (DIFFUSION)
Diffusion of water (OSMOSIS)

29. Facilitated Diffusion
Diffusion with the assistance of transport proteins

30. Cell Cycle
Interphase – preparation for nuclear division
Mitosis – division of the nucleus
Cytokinesis – division of the cytoplasm

31. Interphase
Gap 1
Synthesis
Gap 2

32. Mitosis
Prophase
Metaphase
Anaphase
Telophase

33. Cancer
The uncontrolled growth and division of cells
Substances known to cause cancer are called carcinogens

34. Haploid vs. Diploid
Haploid – n - gametes
Diploid – 2n – body cells

35. Meiosis
Production of gametes, or sex cells
Often called reduction division
RECALL – Crossing-over occurs during prophase I of meiosis

36. Genetics
Branch of biology focusing on heredity

37. Homozygous
Contains two of the same alleles
AA, aa

38. Heterozygous
This is when an organism has two different alleles
Aa, Yy

39. Genotype vs. Phenotype
The genotype is the organism’s allele pairs.
The phenotype is the physical appearance or outward expression of an allele pair.

40. Carrier
An individual who is heterozygous for a recessive disorder and shows no symptoms of the disorder

41. Examples of autosomal recessive disorders
Cystic fibrosis
Albinism
Galactosemia
Tay-Sachs disease

42. Examples of Dominant Disorders
Huntington’s disease
Achondroplasia

43. Sex-linked Recessive Disorders
Red-green colorblindness
Hemophilia

44. Pedigree
A diagram that traces the inheritance of a particular trait through several generations

45. Incomplete Dominance
The heterozygous phenotype is in between the two homozygous phenotypes
A pink flowered snapdragon is produced from parents in which one had red flowers and one had white flowers.

46. Codominance This is when both alleles are expressed at the same time.
Roan horse – both red hair and white hair

47. Sex-linked Traits
Traits controlled by genes located on the X chromosome
Since males have only one X chromosome, they are affected by sex-linked recessive more often than females.

48. Nucleotide
5-carbon sugar
Phosphate
Nitrogenous base

49. DNA Deoxyribonucleic acid Double helix Five-carbon sugar - deoxyribose
Bases: adenine, thymine, guanine, cytosine

50. Chargaff’s Rule
Adenine pairs with thymine
Guaning pairs with cytosine

51. RNA Ribonucleic acid Generally a single-strand
Five-carbon sugar is ribose
Bases: adenine, uracil, guanine, cytosine

52. Three Major Types of RNA
Messenger RNA (mRNA) – travel from nucleus to cytoplasm and direct the synthesis of proteins
Ribosomal RNA (rRNA) – associate with proteins to form ribosomes
Transfer RNA (tRNA) – transport amino acids to the ribosome

53. Semiconservative Replication
Method of DNA replication in which parental strands separate, act as templates, and produce molecules of DNA with one parental strand and one new DNA strand.

54. Three Main Stages of Replication
Unwinding – DNA helicase
Base pairing – DNA polymerase
Joining – DNA ligase

55. Transcription
Synthesis of RNA

56. Translation
The code is read and converted to make a protein

57. Evolution
Cumulative changes in groups of organisms through time