DAT - Science - Biology

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DAT - Science - Biology
2015-03-01 22:59:21
DAT Science Biology
DAT Biology review flashcards (Kaplan)
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  1. What causes the BP to gradually drop as blood flows from artery to capillary?
    1.  Friction between blood and blood vessel walls (decreasing velocity due to small capillary diameter).

    2. Increase in total cross-sectional area (total cross sectional area of branching capillaries are much greater than the cross sectional area of arterioles).
  2. Why is there a decrease in cell size during cellular cleavage (or rapid mitotic division)?

    What other aspects of the cells increase?
    Amount of cytoplasm in the group of cells doesn't change, therefore:

    •      - Volume of the individual cells decreases.
    •      - Increase in the surface-to-volume ratio, thus increasing the amount of nutrient and gas exchange that each cell can participate in.
    •      - There is also an increase in nuclear-to-cytoplasmic ratio because cytoplasmic material decrease in each cell but nuclear material remains consistent between cells.
  3. How many ATP molecules are yielded from each NADH molecule produced during the following metabolic processes:

    1. Glycolysis
    2. Kreb Cycle
    1. NADH from glycolysis produces 2 ATPs.

    2. NADH from the Kreb Cycle produces 3 ATPs.
  4. What is the final product of glycolysis?

    Reminder: glycolysis is anaerobic.
  5. Under what process is ATP produced during glycolysis?
    Substrate level phosphorylation
  6. What are the raw materials of the earth's primitive environment?
    The earth's primordial environment ("primordial soup") contained simple organic and inorganic compounds to include:

    • Salts
    • Methane
    • Ammonia
    • Hydrogen
    • Water

    These are the key ingredients for the synthesis of organic molecules such as sugars and amino acids.
  7. Review glycolysis pathway

    • DHAP = Dihydroxyacetone phosphate
    • GLAP (or PGAL) = Phosphoglyceraldehyde
  8. Anaerobic respiration (animals)
  9. Review Citric Acid (Krebs) Cycle.
  10. Citric Cycle (detailed):
  11. Review the Glycerol-Phosphate Shuttle

    (Note: this is the reason why NADH from glycolysis yields 2 ATPs when e- from NADH is transferred via the Glycerol-Phosphate Shuttle)
  12. Review the Malate-Aspartate Shuttle:
  13. Review the electron transport chain (oxidative phosphorylation).
  14. What is produced in non-cyclic photo-phosphorylation during the light reaction?
    ATP and NADPH
  15. Describe the general concept of the cyclic pathway (involving ONLY photosystem I) during the light reaction of photosynthesis.
    - Light striking chlorophyll excites electrons into a higher energy state.

    - Those hi-E electrons are then passed down an e-transport chain.

    - The E is then used to create a proton gradient that can be used to make ATP (as in oxidative phosphorylation in mitochondria).

    - The electrons are returned to chlorophyll, completing the cycle.
  16. Describe the general concept of the non-cyclic pathway (involving photosystem I AND II) during the light reaction of photosynthesis.
    - Light striking chlorophyll (in photosystem II) excites electrons into a higher E state.

    - High-E electrons are passed along the ETC.

    - The E is then used to create a proton gradient that can be used to make ATP.

    - Instead of the electrons returning to chlorophyll, they are transferred to photosystem I and are again excited to a high-E state.

    - The hi-E electrons are then transferred to NADP+ to form NADPH.

    - The chlorophyll molecule in photosystem II is then left with an electron "hole" to fill.

    - This is accomplished by the splitting of H2O, producing H+ and O2. (products in addition to ATP and NADPH)
  17. What is the probability of two heterozygous parents for the following number of traits having offspring that are homozygous dominant for the trait:

    1. one trait
    2. two traits
    3. three traits
    One trait: 1/4

    Two traits: 1/4 x 1/4 = 1/16

    Three traits: 1/4 x 1/4 x 1/4 = 1/64
  18. Describe Mendel's Law of Independent Assortment.
    Mendel's Law of Independent Assortment states that if traits are on DIFFERENT chromosomes, then the alleles of these different traits should separate independently of each other into different gametes.

    Also, only true for genes that are far apart from each other on the same chromosome to be separated during recombination (during metaphase of meiosis where chromosomes line up and arms cross-over each other).

    The likelihood of two genes on the same chromosome separating independently from each other increases with the distance between the two genes.
  19. Describe Mendel's Law of Dominance.
    The law states that one factor (gene) of a pair may mask or inhibit the expression of the opposite member (recessive) of the pair.
  20. Describe Mendel's Law of Segregation.
    This law states that the members of a pair of genes separate, or segregate at the time of segregation.
  21. Describe Mendel's Law of Unit Characters.
    This law states that inheritable factors occur in pairs, and each pair acts as a unit to control the inheritance of a particular trait.
  22. Cellular respiration produces ___ ATP/mol of glucose.
    36 ATPs/mol of glucose

    Cellular respiration consists of:

    • - glycolysis
    • - Krebs cycle
    • - Oxidative phosphorylation
  23. Prokaryotes (e.g. bacteria, cyanobacteria (blue-green algae)) are found in what kingdom?
    Kingdom Monera
  24. What tissue types are derived from embryonic mesoderm?
    The mesoderm (middle germ layer) gives rise to:

    Heart, musculature, skeletal system, notochord, connective tissue (including blood), cartilage, bone marrow, epithelia (surface, or lining, tissues) of blood vessels, lymphatic vessels, body cavities, kidneys, ureters, gonads (sex organs), genital ducts, adrenal cortex, and certain other tissues.
  25. What does the ectoderm form?
    This forms the nervous system (which includes the retina), lens of the eyes, and skin.
  26. What does the endoderm form?
    This forms the lining of the digestive, respiratory tracts, and bladder; parts of the liver, pancreas, & thyroid.
  27. What events occur during telophase?
    Telophase is the final step in a mitotic or meiotic cell division, resulting in two distinct daughter cells.

    • 1. The chromosomes (or chromatids) have already uncoiled and separated.
    • 2. Reassembly of the nuclear membrane.
    • 3. Reappearance of the nucleoli.
    • 4. Dismantling of the spindles.
  28. What is the function of mutases?
    They remove erroneous nucleotides from DNA.
  29. What is the function of esterases?
    They cleave ester bonds.

    Note that lipase is therefore an esterase (a lipid is composed of an alcohol (glycerol) bound to three FAs.
  30. What is the First Law of Thermodynamics?
    Total energy within an isolated system remains constant.

    • - "E can neither be created nor destroyed"
    • - Provided that the environment does not exchange mass or energy with its surroundings.
  31. Name the parts of a sarcomere:

    • A. Actin (thin filament)
    • B. M-line
    • C. H-zone - located at center of A-band; contains only thick filaments.
    • D. Z-line (or Z-disc) - defines the boundaries of a single sarcomere and is where thin filaments are attached to.
    • E. Titin
    • F. Myosin (thick filament)
    • G. Z-line (or Z-disc)
    • H. I-band
    • I. A-band (dark) - contains entire length of thick filaments & any overlap of thin filaments.
    • J. I-band (light) - contains thin filaments only; located between A-bands.
  32. What is the formula for the Hardy-Weinberg principle?
    p2 + 2pq + q2 = 1   and

    p + q = 1

    - These terms explain the genotypic frequencies of two alleles, wherein:

    • p = dominant allele
    • q = recessive allele
  33. What is continuous with the outer nuclear membrane so that the space between the inner and outer nuclear membrane is directly connected with the lumen of this.
    Endoplasmic reticulum
  34. This is a rare, inheritable, random change in the genetic code required for the display of a trait that has never before appeared in an organism.
  35. This is the random change in frequencies o already existing alleles or phenotypes due to a population becoming isolated from a larger population.
    Genetic drift
  36. This is a gradual divergent differentiation of a species in response to environmental pressures.
    Selective pressure
  37. This describes a pattern of evolution in which species move from separate to common species due to similar environmental pressures.
    Convergent evolution
  38. These are decomposers that absorb their nutrients from dead organic material.
  39. This is the process by which ATP is synthesized via the Krebs cycle and the ETC.
    Oxidative phosphorylation
  40. This is a group of invertebrate that possesses a coelom, as well as a defined nervous, circulatory and excretory system.

    Coelom: the internal body cavity that develops from the embryonic mesoderm.

  41. This is a process by which the presence of one tissue influences the development of others (embryology).

    - For example, retinal cells release chemicals signalling nearby cells to form the rest of the eye.

    - Another example: notocord releases chemical signals that tell the overlying ectoderm that it is time for it to become the neural tube.

  42. In prokaryotes, single circular molecule of DNA is localized in this region of the cell.
  43. In prokaryotes, where is the site of cellular respiration?
    Directly at the cell membrane.
  44. Roles of microtubules and microfilaments in cell division.
    • Microtubules:
    •    - form mitotic spindle
    •    - during prophase, radial array forms around centrioles and push the centrioles to opposite poles.
    •    - they attach to the centromeres of sister chromatids along the metaphase plate.
    •    - during anaphase, they shorten and separate the sister chromatids toward opposite poles.

    • Microfilaments:
    •    - after anaphase, microfilaments (actin filaments) and myosin filaments under cell membrane contract
    •    - this causes an indentation of the cell membrane at the metaphase plate --> leading to subsequent division of cell to daughter cells.
  45. Recall base pairing during DNA replication with DNA Polymerase III.
  46. What is conservative replication?
    There is one DNA copy with both parent strands and one with two new strands.
  47. What is semi-conservative replication?
    DNA replication that produces two copies of DNA that each contain one parent strand and one new strand.
  48. What is dispersive replication?
    DNA replication resulting in two copies of DNA that both have pairs of parent and new genetic material interspersed throughout the helix.