Science GHSGT Review

1. Science GHSGT Review Biology

2. What is Biology? • The study of living things • What is considered living? • anything that has the ability to nourish, grow, and reproduce • cells must be present

3. Cell Theory • The cell is considered the basic unit of life. • All living things contain at least one cell. • Cells come from pre-existing cells.

4. Plant Cell versus Animal Cell Plant Cell Animal Cell

5. Plant Cell versus Animal Cell Plant Cell Animal Cell round/circular shape centrioles (responsible for cell reproduction) • oblong/square-like shape • cell wall (provides structure) • chloroplast (location of photosynthesis/ energy production)

6. Cell Organelles

7. Cell Organelles (continued)

8. Prokaryotes versus Eukaryotes Prokaryotes Eukaryotes “Eu-True” True nucleus Well organized membrane Membrane – bound organelles Most plants and animals and other specialized organisms • “Pro-No” • No true nucleus • No membrane-bound organelles • No well-organized membrane • All prokaryotes are bacteria (Monera)

9. Active versus Passive Transport Active Transport Passive Transport diffusion (particles from high concentration to low) osmosis (water from high concentration to low) facilitated transport (diffusion using a membrane protein) • requires energy (low concentration to high) • endocytosis and exocytosis • active transport (ATP is used)

10. Organic Compounds

11. Cell Membrane and Homeostasis • Homeostasis = The maintenance of a constant, stable environment internally (ex: body temperature) • Cell membrane utilizes active and passive transport • diffusion and osmosis depends on environment (hydrophobic or hydrophilic)

12. Hydrophilic versus Hydrophobic Hydrophilic Hydrophobic “water-fearing” outside of cell • “water-loving” • inside of cell

13. Hypertonic versus Hypotonic HypOtonic Hypertonic Higher concentration of water inside cell Cell shrinks when placed in hypertonic solution • Higher concentration of water outside the cell • Cell swells when placed in hypotonic solution • Isotonic • Equal concentrations of water inside and outside of cell

14. Genetics • The study of the inheritance of traits and how genes pass on these traits from parents to offspring • Mendel is the Father of Genetics (studied pea plants)

15. Important Genetics Vocabulary • trait: a characteristic of an organism that is inherited (examples: eye color, hair type, etc.) • gene: basic unit of heredity made of DNA that determines the characteristics of a trait • allele: the two different versions of a gene for a particular trait (one received from each parent)

16. Genotype versus Phenotype Genotype Phenotype the physical appearance of a trait expressed by the organisms genes represented by description (example: brown eyes) • an organism’s genetic makeup • includes the two alleles • represented with two letters (example: Bb)

17. Dominant versus Recessive Dominant Recessive An allele whose effects are hidden by a dominant allele Represented with a lower-case letter example: Bb (dominant brown eyes dominates over recessive blue) • an allele that expresses itself while hiding the effects of another allele • represented with a capital letter • example: Bb (dominant brown eyes dominates over recessive blue)

18. Probability and Punnett Squares • Probability is the likelihood an event will occur • Geneticists use Punnett squares to predict the probability of genetic combinations • Example: When two heterozygous brown eyes mate . . .

19. Theory of Inheritance • Chromosomes are the physical basis of inheritance (carry DNA). • Variability results from dominant and recessive alleles. • The chromosomes in the male gamete and female gamete join together during fertilization to form a zygote. • gamete = sex cell • zygote = fertilized egg

20. DNA • deoxyribonucleic acid • found in chromosomes in the nucleus • determines the hereditary traits of an organism • contains all the information needed for the production of proteins • protein sequences determine traits

21. RNA • ribose nucleic acid • aids in protein synthesis in the ribosome • 3 types: • messenger RNA: mRNA carries the DNA nucleotide sequence for a protein from the nucleus to the ribosome • transfer RNA: tRNA transports amino acids (building blocks of proteins) to the ribosome • ribosomal RNA: rRNA makes up the structure of the ribosome

22. DNA Replication • self-duplication of the genetic material • results in two new DNA molecules • occurs during interphase (just before cell divides) • proteins unwind the DNA helix and each strand acts as a template for a new strand • unbound nucleotides attach . . . • A-T (adenine binds with thymine) • C-G (cytosine binds with guanine)

23. DNA Transcription • to “transcribe” is to copy • mRNA is synthesized in the cell nucleus from the DNA molecule • Just as in replication, the helix unwinds and free nucleotides attach to make mRNA. . . • C-G (cytosine binds with guanine) • U-A (uracil binds with adenine) • Only DNA has thymine • mRNA separates and moves out of the nucleus • DNA double helix reforms

24. DNA Translation • process of translating the genetic code to the amino acid sequence • tRNA decodes the mRNA to read the DNA in order to make the correct protein

25. Mutations • A mutation is any change in the DNA sequence. • A change in one nucleotide may cause a change in the structure of the protein. • During pregnancy, observing a karyotype (a chromosome picture) can detect chromosomal defects.

26. Taxonomy • The study of the classification of organisms

27. Classification • Kingdom • Phylum • Class • Order • Family • Genus • Species • King • Phillip • Cried • Out • For • Good • Soup

28. Binomial Nomenclature • Classification system used to give all organisms a two-part name • First name = Genus name • Second name = Species name • Example: • scientific name of a wolf is Canis lupus

29. Kingdom Monera • bacteria • need water, nutrients, and a moderate temperature to survive • autotrophs (make their own food) and heterotrophs (obtain food from outside source) • decomposers (AKA saprophytes) = break down dead organisms to release carbon and nitrogen • reproduce asexually (binary fission) • some possess flagella used for motion

30. Kingdom Protista • algae, seaweed, protozoans, water (slime) molds • found in aquatic or damp environments • organisms that don’t fit in any other kingdom • autotrophs (algae) and heterotrophs (protozoans) • reproduce either asexually or sexually • some have flagella or cilia for motion • gave rise to all other eukaryotic organisms

31. Kingdom Fungi • mushrooms, yeast, molds, mildews, rusts • all are heterotrophs (do not contain chlorophyll) • absorb food from environment • many are saprophytes (decomposers) that obtain nutrients from dead or decaying plants and animals • reproduce either asexually or sexually

32. Kingdom Plantae • autotrophs (utilize photosynthesis) • Two groups: • bryophytes (nonvascular) have no roots, stems, or leaves and transport nutrients using diffusion (examples: mosses, liverworts, hornworts) • tracheophytes (vascular) have roots, stems, and leaves that transport water and nutrients throughout the plant (examples: ferns, gymnosperms, and angiosperms) • all reproduce both sexually and asexually (alternation of generations)

33. Kingdom Animalia • worms, insects, sponges, birds, mammals • all are heterotrophs that have a digestive cavity in which food is digested and absorbed • all reproduce sexually, but some (like jellyfish) can also reproduce asexually

34. Unicellular versus Multicellular Unicellular Multicellular multi-celled composed of many cells all other organisms (fungi, plants, & animals) cells are specialized to perform different functions • single-celled • composed of one cell • all bacteria and protists • non-specialized cells

35. Asexual versus Sexual Reproduction Asexual involves two parents so genetic diversity is increased specialized male and female sex cells (gametes) are produced gametes fuse during fertilization to produce a zygote (fertilized egg) gametes are formed in meiosis chromosomes are duplicated in mitosis • involves only one parent • no specialized sex cells are produced • does not undergo meiosis • chromosomes are duplicated in mitosis • Examples: • binary fission = cell simply splits • budding = offspring grows out of the side of the parent

36. Haploid versus Diploid Haploid Diploid all non-sex cells contain 2 copies of each chromosome human diploid number is 46 (two sets of 23 – a set from each parent) • sex cells • contain one of each chromosome • human haploid cells have 23 chromosomes

37. Mitosis • begins after interphase = cell growth, chromosome (DNA)replication, and prep for division (most of a cell’s life cycle is spent in interphase) • results in two identical daughter cells containing same number of chromosomes and genetic information as the parent cell

38. Phases of Mitosis • Prophase = chromosomes become visible (present), nucleus membrane disappears, and in animal cells, centrioles move to opposite sides of the cell • Metaphase = chromosomes line up in the middle of the cell • Anaphase = chromosomes move toward opposite poles of the cell (move away) • Telophase = chromosome become less distinct and nucleus membrane reappears; nucleus divides into two (cytokinesis)

39. Cytokinesis • occurs after telophase • cytoplasm divides forming two separate cells

40. Phases of Mitosis

41. Meiosis • cell division that results in the formation of haploid gamete cells (sex cells) • Meiosis I • reduction division • diploid cell divides creating two haploid cells • Meiosis II • two haploid cells from meiosis I divide resulting in 4 haploid daughter cells

42. Mitosis versus Meiosis Mitosis Meiosis resulting cells have half the number of chromosomes as parent cell used for gamete formation • resulting cells have same number and kind of chromosomes as parent cell • used for cell growth, tissue repair, and asexual reproduction

43. Ecology • The study of interactions among organisms and between organisms and their environment

44. Biomes • Biome = a large area characterized by a certain climate and types of plants and animals • 6 major biomes on Earth

45. Biome Characteristics

46. Biomes of the Earth

47. Ecosystem Vocabulary • Ecosystem = a part of the environment with its organisms, their interactions, and the physical and chemical factors that affect them • Community = populations of different species that interact in an ecosystem • Population = all the individuals of the same species living in a community

48. Members of an Ecosystem • Producers = organisms that can make their own food; autotrophs; examples: bacteria, protists, plants • Consumers = organisms that eat other organisms to get energy; heterotrophs; examples: fungi and animals

49. Consumer Classification • Herbivore= primary consumer who only eats plants; example: cow • Carnivore = secondary consumer who only eats other animals; examples: shark and tiger • Omnivore = consumer that eats both plants and animals; example: most humans • Scavengers = animals that find dead plants or animals and eat them; examples: flies, wasps, cockroaches, earthworms • Decomposers = break down dead organisms to receive energy; examples: fungi and bacteria

50. Predator versus Prey • All animals must eat to survive. Animals can be either predators or prey. • Predators hunt prey. • With predators always on the lookout for a meal, prey must constantly avoid being eaten. • Any adaptation the prey uses adds to the chances of survival for the species. • Some adaptations are defense mechanisms which can give the prey an advantage against enemies.