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EOCT Review. Biology EOCT: May 14 th , 2013. Cell Structure. What is the difference between a prokaryote and eukaryote?. Prokaryote : NO nucleus, only cytoplasm, cell membrane, ribosomes and DNA Small, unicellular
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EOCT Review Biology EOCT: May 14th, 2013
What is the difference between a prokaryote and eukaryote? • Prokaryote: NO nucleus, only cytoplasm, cell membrane, ribosomes and DNA • Small, unicellular • Eukaryote: Nucleus, as well as cytoplasm, cell membrane, ribosomes and other organelles • Larger, multicellular
What are the main differences between plant and animal cells? • Plant: cell wall, chloroplast, large central vacuole; autotrophic • Animal: lysosomes, centrioles; heterotrophic
Tell the function of the following organelles: • Nucleus: contains instructions for building proteins (DNA) • Ribosome: synthesizes (makes) proteins • Mitochondria: performs cell respiration; provides energy • Chloroplast: performs photosynthesis; provides energy • Golgi apparatus/body: processes and packages proteins • Cell membrane: regulates what enters and leaves the cell • Cell wall: provides extra protection • Vacuole: stores food, water and other essential nutrients
The cell membrane is said to have selective permeability. What does that mean? • Only certain things can enter and leave; it “selects” what goes in and out
What is the difference in passive and active transport? • Passive Transport: moves molecules down the concentration gradient from an area of high concentration to an area of low concentration; no energy required • Active Transport: moves molecules up the concentration gradient from an area of low concentration to an area of high concentration; energy required
What is the difference in diffusion, facilitated diffusion and osmosis? What are specific molecules that use these processes? • Diffusion: moves small molecules directly through the cell membrane; carbon dioxide and oxygen • Facilitated Diffusion: moves large molecules through the cell membrane using protein channels; glucose • Osmosis: moves water molecule directly through the cell membrane • All are types of passive transport
Explain the difference in a hypotonic, isotonic and hypertonic solution. • Hypotonic: a solution with more water than particles; water rushes into the cell • Isotonic: a solution with equal parts water and particles; water moves equally in and out of the cell • Hypertonic: a solution with more particles than water; water rushes out of the cell
What is the difference in endocytosis and exocytosis? • Endocytosis: movement of large amounts of particles into the cell; cell “engulfs” • Exocytosis: movement of large amounts of particles out of the cell; “exit” • Both are types of active transport
List and describe the function of the four macromolecules. • Carbohydrates: provide immediate energy (sugars) • Lipids: provide stored energy (fats) • Proteins: build muscle and bone, fight disease, transport materials through cell membrane • Nucleic Acid: contain instructions for building proteins (DNA and RNA)
What are the building blocks of proteins? • Amino acids
What is an enzyme (how do they act as catalyst)? What macromolecule are they? What three letters do they usually end in? • A protein that catalyzes (speeds up) a chemical reaction • Protein • -ase
What is the amount of energy needed to start a chemical reaction? • Activation energy
What is a substrate? • What the enzyme is doing work on • Example: lactose is the substrate of lactase
Why is the “lock and key” analogy a good analogy to explain enzymes? • Because just like a lock and key are specific for each other so are enzymes and substrates
Explain what photosynthesis is and why it is so important. • The process of using light energy (sunlight) to convert water and carbon dioxide into glucose and oxygen. • How plants (and all autotrophs) obtain energy (make food).
Write the equation in word and formula form for photosynthesis. Word: water + carbon dioxide glucose + oxygen Formula: 6H2O + 6CO2 C6H12O6 + 6O2
What molecule absorbs light in the process of the photosynthesis? • Cholorphyll
What organelle does photosynthesis take place in? • chloroplast
What is the purpose of cell respiration? • To break down glucose in order to make ATP
What is the energy molecule used by the cell (36 get made during cell respiration)? • ATP
Write the equation for cell respiration in words and formula form. • Words: oxygen + glucose carbon dioxide + water • Formula: 6O2 + C6H12O6 6CO2 + 6H2O
What is the purpose of glycolysis (remember, all organisms use this) and how many ATP get made here? What are the other two steps of cell respiration (the two where most of the ATP gets made and only happen in eukaryotes)? • Glycolysis: breaks down glucose into two molecules of pyruvic acid • 2 ATP made • Krebs Cycle and Electron Transport Chain (ETC)
What organelle does cell respiration take place in? • Glycolysis: cytoplasm • Krebs and ETC: mitochondria
How are photosynthesis and cell respiration related to each other? • The products of one are the reactants of the other.
What are the base pairs of DNA? Of RNA? Which ones pair together? • DNA: • Adenine (A) and Thymine (T) • Cytosine (C) and Guanine (G) • RNA: • Adenine (A) • Uracil (U) • Cytosine (C) • Guanine (G)
What is DNA replication? Why is it important? • Duplication of a DNA molecule (copying) • So that when cells divide, the new cell made has an identical copy of DNA to the original
What is transcription? • The transcribing of the information in a DNA molecule to an mRNA molecule. • DNA giving its information to mRNA
What is translation? • Using the information of mRNA to make a protein.
There are three types of RNA: mRNA, tRNA and rRNA. Explain the role of each one. • mRNA: messenger RNA; takes DNAs message to the rest of the cell • tRNA: transfer RNA; takes amino acids to the ribosome • rRNA: ribosomal RNA; makes up structure of ribosomes
Explain the processes of mitosis and cytokinesis. • Mitosis: division of the nucleus; has four phases: prophase, metaphase, anaphase and telophase (PMAT) • Cytokinesis: division of the cytoplasm
Briefly describe the four phases of mitosis. • Prophase: nuclear membrane disappears, chromosomes appear • Metaphase: chromosomes line up along equator of cell • Anaphase: chromosomes separate at centromere and move to opposite poles • Telophase: nuclear membrane forms around each group of chromosomes
What is the difference in a haploid and diploid cell? • Haploid: has half the number of chromosomes (humans have 23); gametes (sperm and egg) • Diploid: have a full set of chromosomes (humans have 46); body cells
How many cells do you end up with at the end of meiosis? What type of cells are they? • Four • Haploid; Gametes
Distinguish between the following mutations: insertion, deletion, substitution • Insertion: an extra nucleotide is inserted into a DNA strand • Deletion: a nucleotide is deleted from a DNA strand • Substitution: one nucleotide is substituted for another
What are the advantages and disadvantages of sexual and asexual reproduction? • Sexual: • Advantage: genetic diversity • Disadvantage: slow • Asexual: • Advantage: fast • Disadvantage: no genetic diversity
Explain what the following terms mean: • Dominant: allele that shows when more than one is present (AA or Aa) • Recessive: allele that shows only when two copies are present (aa) • Gene: piece of DNA that codes for a specific trait • Allele: different forms of a trait (blue eyes, brown eyes) • Genotype: the genetic material of an organsims • Phenotype: the physical characteristics of an organism • Homozygous: two of the same allele (AA or aa) • Heterozygous: two different alleles (Aa) • Monohybrid:punnett square that looks at one trait (4 squares) • Dihybrid:punnett square that looks at two traits (16 squares)
Explain Mendel's three laws: • Law of Dominance: some alleles are dominant and some are recessive • Law of Segregation: alleles segregate (separate) independently of each other; one copy goes to each gamete • Law of Independent Assortment: genes for different traits can segregate independently during the formation of gametes (meaning that just because an organism is dominant for one trait doesn’t mean they will be dominant for all)
What is the main source of genetic variation? • mutations
List the levels of organization and give a brief description of each. • Organism: one single individual (lion) • Population: a group of the same organisms (lions) • Community: different populations that live in the same area (lions, giraffes, elephants) • Ecosystem: all the organisms in one area along with the non-living factors (lions, giraffes, elephants, waterhole, frequent fires, dry soil) • Biome: group of ecosystems that have same climate (savanna, tundra, rainforest)
What is a series of steps that shows how energy flows through an ecosystem? • Food chain
What amount of energy is transferred from one trophic level to the next? In an ecosystem, if the producer has 6000 kcal of energy, how much energy would the quaternary consumer have? • 10 % of energy is transferred Producer: 6000 Primary Consumer: 600 Secondary Consumer: 60 Tertiary Consumer: 6 Quaternary Consumer: 0.6
Distinguish between the following: producer/autotroph and consumer/heterotroph. Give an example of each. • Producer/autotroph: makes own food via photosynthesis or chemosynthesis • Plants, algae • Consumer/heterotroph: must consume food • Animals, fungi