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BIOL 1441 Exam #3

Gia Phan English 110 cards

BIOL 1441 Exam #3

Cards in this deck (110)

  1. 1What are autotrophs?They're "self (auto)-feeders (troph)" meaning they take in inorganic materials and make organic molecules as food
  2. 2What are heterotrophs?They're "other (hetero)-feeders (troph)" meaning they can't make their own food
    - A.K.A. consumers
  3. 3What are photoautotrophs?Organisms that create food through sunlight
    - Only materials they require are: water, CO2, minerals (from soil), sunlight
    - Most plants, not all
  4. 4Photosynthesis can also occur in which other organisms besides plants?- Algae
    - Protists
    - Prokaryotes
  5. 5What are the 2 stages of photosynthesis?1) Light reaction (photo)/LIGHT DEPENDENT: solar energy captured & transformed into chemical energy
    2) Calvin cycle (synthesis)/LIGHT INDEPENDENT: chemical energy is then used to make organic molecules A.K.A. make sugar
  6. 6Where is the site of photosynthesis?Chloroplasts
    - More broadly usually in leaves or any green parts of a plant
    (Do not get confused w/ chlorophyll which is a pigment)
    Essentially...
    - Light energy is absorbed BY CHLOROPHYLL which drives synthesis IN CHLOROPLAST
  7. 7Where are chloroplasts mainly found in a leaf's cell?The MESOPHYLL which is the inner tissue of a leafWhere are chloroplasts mainly found in a leaf's cell?
  8. 8Where does CO2 enters and O2 exits in leaves?Through small pores called the STOMATA
    - Note that the whole section is the mesophyll and attached to the lining are the stomatas    Where does CO2 enters and O2 exits in leaves?
  9. 9Plants respire in the roots too, but why do the even need to absorb O2?DO NOT get confused or think that plants ONLY uses photosynthesis; they have mitochondrias that go through CELLULAR RESPIRATION TOO!
    (Recall that cellular respiration requires O2...)
    - Plants can ONLY perform photosynthesis when there's sunlight
    - To keep their cells alive, plants respire just like animal cells when photosynthesis cannot occur
    - The roots can "breathe" or absorb O2 for cellular respiration
    - Sugar is used (broken down) for energy
  10. 10Let's talk about the structure of a chloroplast! (So you know which and where reactions happen)- Stroma: The dense FLUID that fill up a chloroplast (DO NOT get confuse with stomata)
    - Thylakoids: interconnected membrane sacs (chlorophyll located IN the membranes of thylakoids)
    - Thylakoid space/Lumen: Inside of thylakoid
    - Granum: Stack of thylakoid
  11. 11***MIND MAP*** Into a Chloroplast1) Plant
    2) Leaf (or any green parts)
    3) Leaf cell
    4) Mesophyll of leaf cell
    5) Chloroplasts in mesophyll
    6) Chloroplast has double membrane
    7) Outer membrane, intemembrane space, inner membrane
    8) Stroma (like cytosol)
    9) Grana (1 stack) or granum (mulitple grana)
    10) Grana made of thylakoid (chlorophyll in thylakoid's membrane)
    11) Lumen inside of thylakoid    ***MIND MAP*** Into a Chloroplast
  12. 12Is the first stage of photosynthesis, light reaction, anabolic or catabolic?Anabolic, in this stage, the reaction build organic molecules using sunlight, CO2, and H2O
  13. 13Photosynthesis is basically respiration but in _________.Reverse
    - Cellular respiration:
    C6H12O6 + O2 ---> CO2 + H2O + ATP
    - Photosynthesis:
    CO2 + H2O + sunlight ---> C6H12O6 + O2
  14. 14So how does a normal vascular plant gets CO2 and H2O and sunlight in order to perform photosynthesis?- CO2 enters and O2 exits through STOMATAS
    - H2O sucked up by ROOTS and carried to leaves by xylem
    - Sunlight has photons which are absorbed by CHLOROPHYLL
  15. 15The thylakoid membranes are phospholipid bilayers, meaning they're really good at maintaining...?Maintaining the concentration gradients of ions, proteins, and other things
    WHICH basically means it controls what goes in and out; how much ions is in the inside and outside    The thylakoid membranes are phospholipid bilayers, meaning they're really good at maintaining...?
  16. 16Describe STAGE 1 - Light-DEpendent reactions FIRST PROTEIN COMPLEX: ChlorophyllBEGINS IN THYLAKOID
    Starts out in PHOTOSYSTEM II
    1) Photon hits into a molecule of a chlorophyll
    - This action (of the photon hitting the chlorophyll) creates energy that excites an electron
    - Excited electron is now @ higher energy level (DUH.)
    2) This excited electron move to an electron carrier FORMING the ELECTRON TRANSPORT CHAIN
    - This is where redox reactions (oxidation-reduction) occur
    - This journey extracts energy from energized electrons and converts that energy into useful stuff
    - BASICALLY energy is lost from electrons moving down electron transport chain
    3) HOWEVER, when this excited electron moved to an electron carrier and got taken away from the chlorophyll molecule, the chlorophyll FREAKS OUT and wants to replenish the electron it lost
    - So it SPLITS an H2O molecule and steals its electron to replenish the one it lost
    - The byproduct of this split is 2 electrons (obviiii.) 2 hydrogen ions (H+) or called protons, and 1/2 of an oxygen
    - This reaction, my friend, is the reason why we can breathe, oxygen diffuses out of stomata as "waste"
  17. 17Describe STAGE 1 - Light-DEpendent reactions SECOND PROTEIN COMPLEX: Cytochrome complexSTILL in PHOTOSYSTEM II
    1) After all the excited electron are picked up by electron carriers, this protein complex serves as an intermediary btwn PSII and PSI
    2) It uses a little energy from the electron to pump another proton from the stroma into the thylakoid
    - Thylakoid is filling up w/ protons, some from the split of H2O (remember protons (H+), electrons, and 1/2 oxygen) and some from this pump (b/c remember there's more than 30 chlorophyll in PSII and each one does the exact same thing so there's multiple protons coming in from stroma)
    - WHY are we doing this? We're essentially charging up the thylakoid like a battery/we're creating a concentration/proton gradient
    3) The protons naturally repel from each other (since they're all positively charged) so they push their way out/down concentration gradient through enzyme called ATP SYNTHASE
    - This ACTION creates energy that is used to pack a phosphate onto ADP which creates ATP
    - All of this moving around/moving down the electron transport chain will cause these excited electron to enter lower and lower levels of energy
  18. 18Describe Stage I - Light-DEpendent reactions PSINOW IN PHOTOSYSTEM I
    (Similar to PSII but make different products)
    1) NO WORRIES! The depleted and tired electrons are zapped again by photons and are RE-ENERGIZED
    2) Enzyme then helps combine 2 electrons, one proton, & NADP+, creates NADPH (the reduced form of NADP+)
    3) Re-energized electrons then pop off and hitch a ride on another electron carrier
    - HOWEVER, this time all of energy will be used to make NADPH
    4) Protons pumped into thylakoid from stroma from electrons moving down energy levels
    5) Protons leaving through ATP Synthase creates energy that put a phosphate group onto ADP to make ATP. AGAIN. (Cyclic Electron Flow)
    - Generates onl ATP b/c somtimes cycle needs more ATP than NADPH; varies amongst plants
    6) NADPH carries 2 electrons to Calvin Cycle
    - NADP+ is NADP minus 1 e-
    - Add 1 e-: so NADP
    - Add another e-: so NADP-
    - Add 1 proton (H+) from stroma: NADPH
  19. 19What are the ultimate by/products of the first stage/light-dependent reactions?Energy in the form of ATPs & NADPHs and O2 released as "waste"
  20. 20***TEST QUESTION*** How do we get the oxygen that we breathe in?When plants split H2O, it's byproducts are 2 electrons, 2 protons (H+), and 1/2 oxygen. This oxygen is diffused out for us to breathe
  21. 21What is chemiosmotic phosphorylation?Remember the action in PSII when ATP is created? This action is called chemiosmotic phosphorylation. When protons pass through ATP synthase, the free energy that's created is used to make ATP
  22. 22Describe STAGE 2 - Light-INdependent reactions A.K.A. The Calvin Cycle FIRST PHASE: Carbon FixationBEGINS IN STROMA
    This stage is all about using energy from ATPs & NADPHs to produce useful things for the plant
    1) CO2 molecule is fixed to RuBP (which is always in the chloroplast. It marks the start and end point of the Calvin Cycle) w/ help of enzyme called RuBisCo
    - HOWEVER, this CO2 molecule will cause RuBP (a now 6-carbon chain) to become extremely unstable so to regain stability, RuBP breaks apart, making 2 molecules of 3-Phosphoglycerate
  23. 23What is RuBisCo?An enzyme that can suck up CO2 from the atmosphere and convert the inorganic carbon into organic carbon
    - However, because the Earth became so abundant in O2, RuBisCo started slicing O2 instead of CO2, created a toxic byproduct that plants had to evolve to deal with. Plants eventually made enzymes that could break down this toxic byproduct into more useful things
  24. 24Describe STAGE 2 - Light-INdependent reactions A.K.A. The Calvin Cycle SECOND PHASE: Reduction1) Now, we need energy so ATP slams a phosphate group onto the 3-Phosphoglycerate (remember that there's 2 molecules here) and NADPH slaps some electrons on to transform and make 2 MOLECULES of Glyceraldehyde 3-Phosphate/ G3P
    - This is a high-energy 3-carbon compound that plants can convert to carbohydrate likeeeee...
    Glucose for short-term storage
    Cellulose for structure
    Starch for long-term storage
    - BECAUSE OF THIS, G3P is considered the ULTIMATE PRODUCT of photosynthesis
    2) However, this is not the end. We need 5 G3Ps to regenerate 3 RuBPs we started with. We also need 9 ATPs and 6 NADPHs
    THEREFORE,
    we can convert 3 RuBPs into 6 G3Ps but only ONE G3P will leave the cycle (so the other 5 gets used to make original RuBPs)
    3) Regeneration of the RuBPs using 5 G3Ps is the last stage of the Calvin Cycle
  25. 25In this redox reaction: 6CO2 + 12H2O + light ---> C6H12O6 +6O2 + 6H2O what is getting oxidized and what is getting reduced?- Hydrogen is oxidized (loses electrons)
    - CO2 molecule is reduced (gains electrons)
    - Oxygen from water released as molecular (O2)
  26. 26Light reactions occurs where?Occur in the thylakoids
  27. 27The Calvin Cycle occurs where?Occurs in the stroma
  28. 28Summarize the light reactions stage- Split water
    - Release O2
    - Produce ATP
    - Form NADPH
  29. 29Summarize the Calvin Cycle stage- Forms carbohydrates/sugar from CO2 using ATP & NADPH from light reaction stage
  30. 30How do the length of wavelength in light affects its energy level?- Shorter wavelength = higher energy
    - Longer wavelength = lower energy
  31. 31Chlorophyll ___ has the main photosynthetic pigmentChlorophyll a
  32. 32Why is the chlorophyll in PSII (in light reaction stage) called P680 while the chlorophyll in PSI is referred to as P700?Because PSII's chlorophyll a absorbs wavelength of 680 nm while PSI's chlorophyll a absorbs 700 nm wavelength
  33. 33Remember in Stage 1 light reaction in PSII when the excited electron leaves chlorophyll P680 to move to an electron carrier? Explain here what is oxidized and what is reduced.P680 is oxidized and becomes P680+ because is loses an electron, whereas the electron carrier is reduced because it gains an electron
  34. 34Remember in Stage 1 light reaction in PSII when the chlorophyll P680+ freaks out because its electron got taken away? Then it split a water molecule in order to try to replenish the electron it lost? Explain here what is oxidized and what is reduced.The H2O molecule is oxidized because when it got split, the chlorophyll P680+ (becoming P680 again) took its electron so basically it lost an electron while P680+ is reduced (gains an electron)
  35. 35What is the final electron acceptor in the 1st ETC?P700+
  36. 36The 1st ETC ends when P700+ accepts an electron, which also ends the 1st ETC. When does the 2nd ETC starts?The 2nd ETC starts in PSI, when NADPH is formed instead of the creation of ATP
  37. 37Does the water split occur in PSII or PSI?PSII
  38. 38To make 1 G3P, how many molecules of CO2 do you need?3
  39. 39The G3P produced in the Calvin Cycle is also called sugar, but why is this "sugar" not glucose?Because G3P is a 3-carbon sugar, and is used to MAKE carbohydrates LIKE glucose
  40. 40What are the 3 phases of the Calvin Cycle?1) Carbon fixation
    2) Reduction
    3) Regeneration of CO2 acceptor
    A.K.A. regeneration of RuBP (carbon skeleton of 5 G3P rearranged into 3 RuBP)
  41. 41The net synthesis of the Calvin Cycle is 1 G3P, but how many turns is taken?It takes 3 turns because there's 3 CO2 molecules that needs to be cycled
    - Consume 9 ATP
    - Consume 6 NADPH
    - 6 G3P made, only 1 "survives"
  42. 42What is chemiosmosis?Chemiosmosis is the movement of ions across a semipermeable membrane (like membranes in mitochondria and chloroplast) down their gradient. This movement explains how ATP is created
  43. 43PhotorespirationThe build of O2 in the atmosphere causes RuBisCo to bind w/ O2 instead of CO2
    - Makes 2 carbon compound instead
    - Compound leaves chloroplast and gets break down in mitochondria
    - CO2 released as byproduct
    - Produces no ATP or sugar
    - Like cellular respiration
  44. 44What are C4 plants?Plants that uses different mode of carbon fixation to produce 4 carbon compound as 1st product in Calvin Cycle
    Why? BECAUSE these plants lives in hot regions w/ intense sunlight
    - Bundle-sheath cells: arranged into tightly packed sheaths around veins of leaf
    - Mesophyll cells: btwn leaf surface & bundle-sheath cells
    - Carry out cyclic electron flow to generate extra ATP
    Ex: Sugarcane    What are C4 plants?
  45. 45What are CAM plants?Plants that process photosynthesis differently; does light reaction at night and Calvin Cycle in the day
    Ex: Pineapple
  46. 46What is the Greenhouse effect>Some sunlight that hits Earth is reflected while some becomes heat. CO2 and other gases in the atmosphere traps this heat, keeping the Earth warm, just like a Greenhouse.
  47. 47What is cancer?It's just uncontrolled cell growth
    - Cell growth is a normal cellular process to heal wounds, regenerate skin, etc.
    - Difference is those cells know when to stop
    - Genetics play an importantly role here
    - Cells are naturally mutated, but too many mutations in one cell cause it to be cancerous
    - 7-10 mutations in one cell usually    What is cancer?
  48. 48What causes cancer?Accumulation of genetic mutations
    How do you get these mutations?
    Through...
    - DNA Replication
    - Viruses
    - Carcinogens
    - Radiation (UV rays)
  49. 49What are the 2 main phases of the cell cycle?1) Interphase (G1, S, G2)
    2) Mitosis
  50. 50Somatic cells are any cells that aren't _____ cells.Sex cells
  51. 51Describe the main difference between meiosis and mitosisMEIOSIS:
    - Cellular division for gametes A.K.A.
    sex cells (egg, sperm)
    - 23 chromosomes
    - Make NON-identical daughter cells
    MITOSIS:
    - Cellular division for somatic A.K.A. every cell except gametes
    - 46 chromosomes
    - Make IDENTICAL daughter cells
    - Division for growth & repair
  52. 52How many chromosomes are in each somatic cell?46! BUT they're grouped in pairs so 23 pairs in total.
    - 23 chromosomes from your mom
    - 23 chromosomes from your dad
  53. 53Cells w/ all 46 chromosomes are called?Diploid cells
    THEREFORE...
    - ALL somatic cells are diploid cells b/c all of them have 46 chromosomes
  54. 54How many chromosomes are in haploid cells?Only 23!
    - There are no pairs at all
    - ALL haploid cells are gametes or sex cells
    - Gametes go through a cellular division process called meiosis
  55. 55Essentially, mitosis is a process where...Where a cell w/ 46 chromosomes/somatic/diploid split to create 2 genetically identical daughter cells in which case each daughter cell also contain 46 chromosomes
  56. 56Mitosis doesn't really create a WHOLE cell w/ all the different organelles in it...No, it just replicates the DNA inside the nucleus. Once there's "two pockets" that contain these identical DNA, it can grow into a fully developed cell
  57. 57What are the phases of mitosis?1) Prophase
    2) Metaphase
    3) Anaphase
    4) Telophase
  58. 58Describe mitosis in full details INTERPHASEStarts out in a limbo period called INTERPHASE where cell just grow/work/do stuff (when cell isn't in mitosis, it's in interphase)
    - During this stage, DNA is loosely coiled, messy, w/ proteins, called CHROMATIN
    - As mitosis process begins to gear up, cells does all sorts of things to prepare for the division:
    1) Centrosome (pair of protein cylinders) duplicates itself (so now 2 pairs)
    - We're going to have to move a lot of stuff around in the nucleus, and these centrosome regulates it
    2) DNA now replicates itself so there are 2 copies of every strand of DNA
  59. 59Describe mitosis in full details PROPHASE1) Chromatin condenses and coils up, wrapping around the protein & producing thick strands of DNA called CHROMOSOMES
    2) Remember the duplicated strand of DNA? It stays attached to the original & together they look like X's
    - Each strands are called chromatids (when these chromatids separate, they're called chromosomes too)
    - Where they meet in the middle (to X) is called the centromere
    3) As chromosomes are forming, nuclear envelope dissolves
    4) Centrosomes then peel away from nucleus & head to either side of the cell
    - As they go, they leave behind a trail of protein ropes called MICROTUBULES
    - These run from one centrosome to the other
    - Remember that microtubules provide structure for the cell? That's what they're doing here
  60. 60Describe mitosis in full details METAPHASELONGEST PHASE OF MITOSIS
    1) Microtubules attach to the chromosomes at the centromere (middle)
    2) Chromosomes then starts to move themselves w/ help of motor proteins (2 on either side of centromeres to move chromosome)
    3) Motor proteins then attached itself to microtubules and spool up the microtubules' slack
    - At same time, protein called dynein, is pulling up the slack on other end (in cell membrane) THIS ALIGNS the chromosomes in straight line down the middle of cell
  61. 61Condenses what happens in interphase, prophase, and metaphase.INTERPHASE:
    1) Centrosome duplicates
    2) DNA duplciates
    3) Gets ready for mitosis
    PROPHASE:
    1) Chromosomes form
    2) Centrosomes spread apart
    METAPHASE:
    1) Chromosomes align in the middle
  62. 62Describe mitosis in full details ANAPHASE1) Motor proteins pull hard on the ropes & the X-shaped chromosomes split into individual chromosomes
    2) Once detached, they're dragged towards either end of the cell
  63. 63Describe mitosis in full details TELOPHASE1) Each of the new cell structure are reconstructed
    - Nuclear envelope reforms & nucleoli form within them to house the DNA
    2) Chromosomes relax back into messy coils of DNA/chromatins
    3) A crease forms between the 2 new cells called the CLEAVAGE
  64. 64Describe mitosis in full details CYTOKINESIS1) From the cleavage, the cell splits, making a clean break, and creating 2 new daughter cells
    - Done by cytokinesis which literally means "cell movement"
    2) The 2 new nuclei move apart from each other
  65. 65What is the genome?Genome is the total DNA of the cell
    Eukaryotes: Distinguish btwn nuclear genome & mitochondria/chloroplast genomes
    - Consist of multitple chromosomes
    Prokaryotes: Usually single chromosome
  66. 66What are homologous chromosome pairs?Well we have pairs because one chromosome is from your mom, and one from your dad
    - They pair up because they're similar (not identical)
    - Similar as in they contain versions of the same genes/alleles in the same spot for any trait
    - Homologous: homo (same) & logos (relation)
  67. 67What is meiosis?When a specialized diploid cell splits in half, TWICE, making 4 separate cells, each of which is genetically distinct from each other
    - Goes through the same phases (prophase, metaphase, anaphase, telophase) as mitosis but it does it TWICE
  68. 68What are primary oocytes and primary spermatocytes?Depending of what kind of gamete they make, these cells are STOMATA CELLS that are DIPLOID
    - They MAKE gametes, or sex cells that are haploid
    - They are NOT gametes themselves
  69. 69Each pair of chromosomes contains the same genes in the same order, BUT ther versions, ________, can differ depending on DNA sequence variation.Alleles can differ
  70. 70Describe meiosis in full details INTERPHASE1) Key players replicate themselves
    - Centrosome duplicates
    - DNA strands duplicates
    - DNA still in chromatin form (loose w/ protein)
  71. 71Describe meiosis in full details PROPHASE INEARLY IDENTICAL AS MITOSIS' PROPHASE
    1) Centrosome moves to either end of cell
    2) Chromatin condenses, coils up w/ protein to make thick strand called CHROMOSOME
    - Each chromosome is linked to its duplicate to make the X-shaped
    - Once attached, each single chromosome is now called a chromatid, one on each side of the X
    3) Centrosome leave behind trails called MICROTUBULES
    UNLIKE MITOSIS...
    Meiosis has 2 CRUCIAL DISTINCT STEPS
    1) Crossover
    2) Homologous recombination
    Because of these steps, each chromosome will be different from the rest
    ***The point here is to end up w/ 4 sex cells that each have just one single chromosome from each of the homologous pairs***
    4) Each double chromosome lines up next to its homolog (mother's version & father's version)
    - Total of 4 chromatids here
    5) Crossover happens: when the 2 X's gets tangled up
    6) Recombination: They trade sections of DNA
    - Sections that they're trading is on the same location
    - All 4 chromatids are now different
    CREATING VARIATIONS IS KEY TO LIFE
  72. 72Which pair of chromosome doesn't go through crossover and why?The 23rd chromosome, the one that determines the sex of an organism
    - It's because one chromosome is an X while the other is a Y; meaning they're not homologous so they won't trade sections
    - Therefore, females' 23rd chromosomes crossover but males' does not
    - When the pair has to split however, half will result in females, & half are males
  73. 73Describe meiosis in full details METAPHASE II1) All chromosomes WITH ITS HOMOLOGOUS PAIR align in a single row, powered by motor proteins
    2) The slack is tightened by motor proteins on either side of cell and centromeres
  74. 74Describe meiosis in full details ANAPHASE I1) THE HOMOLOGOUS PAIR gets pulled apart by more motor proteins to either end of the cell
  75. 75Describe meiosis in full details TELOPHASE I1) Nuclear envelope and nucleoli forms again around DNA
    2) Chromosomes relax back into chromatin
  76. 76Describe meiosis in full details CYTOKINESIS1) Cleavage forms
    2) New daughter cells separate as nucleolis move away from each other
  77. 77What are the products of "round 1" of meiosis?We now have 2 haploid cells, each w/ 23 chromosomes (instead of 46/diploid like mitosis) that are new, unique combinations of the original chromosome pairs
    - The chromosome STILL are connected at the centromere and still look like X's
  78. 78"Round 2" of meiosis is exactly like mitosis, EXCEPT...Except round 2 of meiosis' goal IS NOT to duplicate the double chromosomes, but instead to PULL THEM APART INTO SEPARATE SINGLE-STRAND CHROMOSOMES
    - Because of this, there's NO INTERPHASE, no DNA replication involved
    1) Prophase II: DNA clumps up into chromosomes; centrosomes move to either side and microtubules shows back up
    2) Metaphase II: Chromosomes align down the middle
    3) Anaphase II: Chromatids are pulled apart into separate, single chromosomes
    4) Telophase II: Chromsomes uncoils back into chromatin, envelope & nucleoli form, crease form
    5) Cytokinesis: Cells move apart
    FROM ONE original cell w/ 46 chromosomes, we now have 4 new cells w/ 23 single chromosomes each
    - If sperm, all 4 cells are same size, just different genetic info, HALF FOR MAKING GIRLS, HALF FOR MAKING BOYS
    - If eggs, only 1 egg is made & 3 polar bodies (useless in animals, useful in plants)
  79. 79What is a karotype?A picture of all the pairs of chromosomes in the genome , organized by chromosome #What is a karotype?
  80. 80The process that prokaryotes go through for cell division is called?Binary fission
    - DNA is replicated
    - Cell elongates (w/ one copy of genome in each half)
    - Then divides down the middle to produce 2 new cells that represent complete organisms
  81. 81To make life EASIER, remember that chromosomes are counted by the # of ____________.Centromeres
    - As long as a pair of sister chromatids are joined at the centromere, this is considered 1 chromosome
    - When they separate, each has its own centromere so these are considered 2 separate chromosome
  82. 82Describe interphase's phases.Most eukaryotic cells spend very little time in the mitotic phase
    G1: Usually in G1
    - Growing & carrying out normal functions
    S: If cell reproduce (mitosis + cytokinesis), it enters S phase
    - DNA is replicated
    - Now committed to mitosis
    G2: Continues to grow & prepares for mitosis
  83. 83Cytokinesis usually overlaps which phase of mitosis?Telophase
  84. 84To be more in depth, there's also "Prometaphase" in mitosis. Describe this stage.- Nuclear envelope disintegrates
    - Microtubules attach to centromeres BUT, to be more in depth, it actually attach to KINETOCHORES, which are proteins surrounding the centromeres that microtubules hook onto
    - Chromosomes BEGIN to line up, forming METAPHASE PLATE
  85. 85How is cytokinesis different in plant cells?First and foremost, plant cells have CELL WALLS
    - Instead of a cleavage like animal cells, plant cells has vesicles that contain cell wall material, line up in the middle of the 2 new daughter cells
    - From these vesicles, a cell plate form
    - Eventually this new cell plate divide the daughter cells completely in half, giving them their own cell walls
  86. 86What is G0 phase?Well cell set up restriction points in order to not replicate uncontrollably (cancer)
    - One of the restriction point is that cell can "decide" whether or not to copy DNA
    - If yes, then S will replicate DNA and carry onto G2
    - If not, cell can enter indefinite G0 phase where cell is active but does not do anything related to mitosis
  87. 87Where are the "checkpoints" in the cell cycle?1) In G1 phase (G1 checkpoint)
    2) At the end of G2 (G2 checkpoint)
    3) In mitosis (M checkpoint)
  88. 88What is anchorage dependence and density-dependent inhibition?Anchorage: After a single layer of cells form on a substrate the cells stop dividing
    Density: When cells become too crowded they stop dividing
    ***CANCER CELLS do not exhibit either inhibition***
  89. 89In MAMMALS, males are the heterogametic sex, which means what?Heterogametic sex mean to have 2 different sex chromosome (X,Y)
    - Females are HOMOGAMETIC (XX)
    - But in birds, for example, this is reversed
    - Male chickens are homogametic (ZZ) while female chickens are (ZW)
  90. 90All the non-sex chromosomes are called?Non-sex chromosomes are called autosomes
    - Meaning 22 pairs are autosomes, while only one pair (that is responsible for determining the sex) is not
  91. 91All the different alleles of a gene (or versions of a gene) trace back to...?They trace back to mutations
    - MUTATIONS CAUSES VARIATION
  92. 92What are phenotypic traits?Phenotypic traits are traits that are "observable"
    - You can physically see these traits
    - Ex: Hair color, height
  93. 93Diploid cells are also displayed asd...?They're also written as "2n" whereas haploid cells are just "1n"
  94. 94When sperm cell fertilzes egg, a 2n zygote is produced. Meiosis produces the ____ gametes.Meiosis produces the 1n gametes
    - So remember, starts w/ one 2n cell and make four 1n cells (not identical)    When sperm cell fertilzes egg, a 2n zygote is produced. Meiosis produces the ____ gametes.
  95. 95What are chiasmata?They're temporary "links" between DNA and chromatids. These are formed during prophase of meisosis during crossover so that the corresponding segments of DNA are traded from one chromatid to the otherWhat are chiasmata?
  96. 96Remember that the end result of round 1 for meiosis is...?Two HAPLOID daughter cells
    - Each chromosome is still a chromatid pair though
  97. 97Who is Mendel?A European monk who experimented on inheritance of states of different traits in pea plants in the 1850s - 1860s
    - Mendel tracked the inheritance of genotypes that determine phenotypes instead of the old days where people considered offsprings to have the intermediate phenotype of their parents (tall + short = average height offspring)
  98. 98What are discrete traits?Traits that are one form or another; no in between (e.g. purple vs. white flowers, round vs. wrinkled seeds)
    - Height is a continuous trait
  99. 99What is monohybrid cross vs. dihybrid cross?Monohybrid cross only compare one character while dihybrid cross compare two charactersWhat is monohybrid cross vs. dihybrid cross?
  100. 100What is the Law of Segregation?States that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization
    -OR-
    During the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent
    - So there's no intermediate results
    - White trait later re-emerged    What is the Law of Segregation?
  101. 101What is the Law of Independent Assortment?Describes how different genes independently separate from one another when reproductive cells develop.What is the Law of Independent Assortment?
  102. 102Compare genotype agaisnt phenotype.Compare genotype agaisnt phenotype.
  103. 103Suppose that you have a pea plant with purple flowers. The phenotype is purple, but you don’t know if the genotype is PP or Pp (because P is dominant). How do you figure this out?Testcross.
    Cross with a white flowered plant. For this one, you know the genotype has to be pp
    If the purple parent is PP, all offspring will be Pp and have the purple phenotype.
    If Pp: about half the offspring will be Pp (purple phenotype) and half pp (white).
  104. 104Segregation of alleles in gametes & fertilization follow basic probability laws. Explain.Just like a coin flip, the chances of getting heads vs. tails are 50% : 50% and events are INDEPENDENT.
    - Chances of 2 independent events happening together are multiplicative
    Similarly, for a heterozygous person (Yy), the chances of producing Y versus y ova or sperm are 50%
    - Chance of Y sperm cell fertilizing Y ovum from another heterozygote is
    50% x 50% = 25%
  105. 105Suppose you have 2 heterozygous individuals. - Male produces 50% Y and 50% y sperm - Female produces 50% Y and 50% y ovaA Y sperm cell could fertilize a y ovum, or a y sperm cell could fertilize a Y ovum.
    Both produce Yy zygote.
    So: Of the offspring, chance of YY = 25%, chance of yy = 25%, and chance of
    Yy = 25% + 25% = 50%
  106. 106What is incomplete dominance?Intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele
    Ex:
    Snapdragon flowers has C^R and C^W (red vs. white) for colors
    - Need 2 copies of either allele to show "full" phenotype
    - Hybrid has intermediate phenotype
    - CRCR x CWCW = pink flower
    - CRCR = red
    - CWCW = white
    - CRCW = pink    What is incomplete dominance?
  107. 107What is codominant?When both alleles are expressed "fully"; no intermediate
    - Neither dominant or recessive
    - Typical example is the ABO blood group system
    Blood type:
    A = IAIA or IAi
    B = IBIB or IBi
    AB = IAIB
    O = ii
    An individual can only have 2 of these genes maximum, BUT 3 alleles can be seen    What is codominant?
  108. 108What us pleiotropy?When a genotype affects multiple aspects of the phenotype
    Ex: Gene for flower color can control the flower color and the seed color
  109. 109What is epistasis?When a phenotype is controlled by multiple genes whos products affect the expression of one another
    Ex: Mice's fur color
    - Fur color has 2 determining alleles
    - One being the B or b (color)
    - Two being C or c (whether pigment is deposited)    What is epistasis?
  110. 110What is polygenic inheritance?Effects of mulitple genes "add" to produce phenotype
    - Affect continuous traits instead of discrete traits
    - Alleles are incomplete dominant
    Ex: Height, weight, skin color    What is polygenic inheritance?

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Flashcards on BIOL 1441 Exam #3, created by Gia Phan on 18/04/2018.
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Gia Phan · Apr 2018
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Apr 24, 2018
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