Answered>Order 27443

1. Which statement best supports the theory of natural selection, taking account our current understanding of inherited traits

  • Genes carry the fitness needed for evolution to take place in the individual
  • The recombination of alleles determines adaptation
  • Mutations within genetic code enable species to evolve as needed
  • Genetic diversity is acted upon by natural selection

2. Population numbers of the blue moon butterfly within the Samoan islands were reduced drastically in 2001. The species experienced a parasite that fed on the male embryos of the population. This created a gender imbalance, and numbers of new individuals dropped dramatically. However, in 2007 the male population bounced back within 10 generations and population numbers increased by 40 percent. The parasite still exists within the population.

  • mutation
  • higher fitness against the parasite
  • low number of surviving males
  •  sexual recombination

3. Which factor provides the best evidence that evolution is occurring from one generation to the next.

  • stability of environmental conditions
  • change within population numbers
  • number of individuals with polymorphic traits
  • frequency of alleles from one generation to the next

4. A dam broke above a river basin undisturbed for 40 years. The flooding caused part of the land to be saturated with excess minerals and salt. The germination rate of a population of lilies was studied both with original nutrient levels and with the newly disturbed soil. The change in minerals resulted in a lack of cross-pollination between flowers in the same population. What is the most likely outcome for the population of lilies if this continues to persist over several generations.

  • fitness would decline because of environmental pressures
  • speciation would occur due to reproductive isolation
  • the reshuffling of alleles would cause increased genetic variation
  • population numbers would decline

5. Which is the most significant function of circular DNA in both prokaryotic and eukaryotic organisms?

  • evidence of evolutionary pathways along which prokaryotes evolved from eukaryotic       organisms
  • synthesis of proteins for the building of mitochondria and ATP production  
  • reproduction of cells without the assistance of the nucleus
  • transfer of genetic material to daughter cells without the recombination of alleles

6.

7. The statements is true about the electron transport chain in mitochondria, but not in chloroplasts

  •  carbon dioxide is generated
  •  ATP molecules are produced
  •  several membrane proteins are utilized
  • oxygen is the final electron acceptor

8. Which describes how polar molecules would diffuse through a semi-permeable membrane?

  •  transport proteins would assist the passage across the cell membrane by providing energy that works against the concentration gradient
  • diffusion would occur through the membrane when molecules are dissolved in water
  •  only polar ions can diffuse across the membrane
  • carrier channels allow the polar ions to transport down the concentration gradient with no extra energy required of the cell

9. The California sea otter lives along the coastline in water temperatures of 35 -68*Fahrenheit. They have a metabolic rate 2.5 times greater than that of other animals the same size that live in terrestrial environments. To maintain this rate, sea otters consume 20~25 percent of their body weight each day

  •  the decrease of external temperatures decreases metabolic rate
  • metabolic heat helps maintain a stable body temperature despite colder water temperatures
  •  homeostasis is maintained because of the energy that the high metabolic rate provides
  • metabolic rate is dependent on internal temperature

10. What is the significance of the protein-lined pits?

  • protein attracts other proteins needed for ATP synthesis within the cell
  • protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell
  • the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels
  • receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis

11. Which best exemplifies a disruption within a negative feedback mechanism?

  • decreased blood flow to extremities in cold temperatures that results in frostbite
  •  decreased amount of contractions and production of oxytocin after childbirth
  •  filling of the stomach with food that caused the brain to discontinue the message of hunger
  •  weaning of a baby and decreased milk production

12.  Which factor would contribute to an increased rate of transpiration occurring within a plant?

  • decreased moisture within the soil
  •  decreased air moment
  • increased ambient temperature
  •  increased humidity within the air

13.  How may aquatic animals adapt to decreased oxygen content within their habitat?

  • enter a state of torpor to save energy and reduce metabolic rate
  • move to lower elevations in water where temperatures are cooler
  • move closer to the surface where oxygen is more available within the atmosphere
  • use metabolic oxygen within cells to maintain homeostasis

14. Which adaptation of homeostasic mechanisms supports the idea of common ancestry within vertebrates?

  • hormone secretion upon stimulation of hypothalamus
  •  housing of respiratory surfaces within the body
  • presence of hemoglobin within the blood
  •  initiation of hypersensitive responses upon recognition of a foreign pathogen

15. Which is the first line of defense for an invertebrate?

  • nonspecific immune response
  • external barriers such as an exoskeleton
  • thorns, waxy cuticles and toxins
  • gene-to-gene recognition

16.  When a bee has discovered a good batch flowers, she flies back to the hive and communicates the location to the rest of the bees. What best explains why the bee exhibits this kind of behavior?

  • Bees act in the best interest of the entire population because their livelihood is connected to the behavior of individuals
  • gene expression allows communication to occur within populations living in large groups
  • energy acquired from within the nectar triggers a hormone that stimulates behavior mechanisms of communication
  • each bee within a population has identical DNA and transfers information by specific innate responses to help increase honey supply for the entire hive

17. Which is an example of gene expression within unicellular organisms?

  •  differentiation between cells
  •  mitosis within eukaryotic cells
  •  reproduction of bacteria by cell division
  • transfer of DNA by means of meiosis

18. Which correctly identifies a characteristic cactus has adapted due to abiotic factors in the environment?

  • a hypersensitive response when the first line of defense is broken
  • low metabolic rates to offset the energy required by increased temperature
  • storing water within cell walls because of the lack of water in the environment
  • spines that limit the amount of vegetation consumed by herbivores

19. Achondroplasia(dwarfism) is an autosomal dominant disorder. Which is possible genotype of the 99.96 percent of people in the world who do not have achondroplasia?

  • AA
  • aA
  • Aa
  • aa

20. Which is an advantage of asexual reproduction compared to sexual reproduction?

  •  mutations occur in most offspring
  • offspring resemble the parents most of the time
  •  energy is not wasted in finding a mate
  •  the population growth rate and diversity stays constant

21. What is a line of defense for a mature strand of mRNA as it exits the nucles?

  •  Proteins surround the strand as it exits
  •  lysosomes perform catalytic reactions with the strand prior to migration
  •  ribosomes are present once the strand leaves the nucleus
  •  structural modifications occur to mRNA prior to its migration

22. Which genetic material is used to make recombinant DNA plasmids used for genetic engineering?

  •  cDNA
  •  mRNA
  •  mtDNA
  •  rRNA

23. mRNA is much shorter than the DNA from which it was transcribed. Which statement best describes why?

  •  RNA is single-stranded, while DNA is double-stranded
  • DNA has coding and non-coding sequenced, so its longer and denser than RNA
  •  non-coding sequences of RNA are spliced out, so the mRNA is transcribed is shorter
  •  excess pieces of DNA are spliced out, and therefore the strand that is transcribed is shorter

24. Which sequence contains the start sequence of a gene?

  •  GTCAGUCCATGA
  •  ACTGCCGGTCCG
  •  GTAGTCGATGCA
  •  GCCTACAATGAC
 
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