National Biology Competition 2016 Question Paper with Solutions - April 28, 2016

Previous Examinations : National Biology Competition 2016

University of Toronto National Biology Competition 2016 Examination Question Paper with Solutions. The Exam was held on Thursday, April 28, 2016. The exam questions will cover material that a senior high school biology student is likely to have come across in their studies.

  1. General biochemistry
    • basic chemical concepts, chemical bonds, biochemical reactions, biologically important organic molecules
  2. Cell structure and processes
    • cell structure and function, membrane structure, transport across membranes
  3. Cell metabolism
    • energy in the cell, enzymes, cellular respiration, photosynthesis, mitosis, cell cycle
  4. Genetics
    • meiosis, sexual and asexual reproduction, Mendelian inheritance, DNA, genes and chromosomes, protein synthesis, mutation, genetic disorders in humans, gene expression and manipulation
  5. Evolution
    • historical context for evolutionary theory, evidence for evolution, population genetics, evolutionary mechanisms, adaptation, speciation, extinction
  6. Biological diversity
    • taxonomy, phylogeny, origin of life, microbial, fungal, plant, and animal diversity
  7. Plant structure and function
    • structure, growth, and reproduction, transport mechanisms, growth regulators
  8. Vertebrate structure and function
    • digestion, circulation, gas-exchange, reproduction, development, homeostasis, excretion, and nervous, endocrine, and immune systems
  9. Ecology
    • species interactions, matter exchange and energy flow, population dynamics, human ecology, conservation biology
  10. "Hot" biology topics in the news
1. During lactic acid fermentation, one molecule of glucose (left figure) is converted to two molecules of lactic acid (right figure). During this reaction, which carbon atoms in glucose (numbered 1 to 6) are reduced and which are oxidized?


[A] Carbons 1 and 3 are reduced; carbons 4 and 6 are oxidized.
[B] Carbons 2 and 5 are reduced; carbons 1 and 6 are oxidized.
[C] Carbons 1 and 6 are reduced; carbons 3 and 4 are oxidized.
[D] Carbons 3 and 4 are reduced; carbons 2 and 5 are oxidized.
[E] Carbons 3 and 4 are reduced; carbons 1 and 6 are oxidized.

Answer: C. Carbons 1 and 6 are reduced; carbons 3 and 4 are oxidized.

2. Which of the following would be found within an autotrophic eukaryotic cell (and not a heterotrophic eukaryotic cell)?
[A] Mitochondria
[B] Ribosomes
[C] Rough endoplasmic reticulum
[D] Chlorophyll
[E] Vacuole

Answer: D. Chlorophyll

3. A botanist wants to breed a new variety of daisy with orange flowers. She crosses a yellow variety with a red variety. She knows that the daisy with yellow petals contains a dominant yellow petal allele and a recessive white petal allele. In which scenario is it possible to obtain an orange flower?
[A] Red petals have incomplete dominance to yellow petals and are dominant to white petals.
[B] Red petals have incomplete dominance to white petals and are recessive to yellow petals.
[C] Red petals are dominant to yellow petals and white petals.
[D] Red petals are dominant to yellow petals and co-dominant to white petals.
[E] Red petals are recessive to yellow petals and dominant to white petals.

Answer: A. Red petals have incomplete dominance to yellow petals and are dominant to white petals.

4. Which of the following mechanisms allows evolutionary biologists to best predict how allele frequencies in a population will change over time?
[A] Mutation
[B] Natural selection
[C] Horizontal gene transfer
[D] Genetic drift
[E] Non-random mating

Answer: B. Natural selection

5. Which statement accurately describes essential amino acids?
[A] They are the only amino acids required for life.
[B] They are the only amino acids to contain sulphur (sulfur).
[C] They can only be obtained by eating meat.
[D] They are the only amino acids required in protein synthesis.
[E] They cannot be manufactured by an organism’s body.

Answer: E. They cannot be manufactured by an organism’s body.

6. In a eukaryotic cell, where does the synthesis of DNA, RNA, and proteins occur? (ER = endoplasmic reticulum)
DNA RNA Proteins

[A] nucleus nucleus nucleus
[B] nucleus cytosol cytosol + ER
[C] nucleus nucleus cytosol + ER
[D] cytosol cytosol nucleus
[E] cytosol nucleus cytosol + ER

Answer: C. nucleus nucleus cytosol + ER

7. The spontaneous self-assembly of phospholipids in an aqueous environment are shown at right. What is the most important contributor to this spontaneous assembly?
[A] Hydrogen bonding of water.
[B] Strong hydrophobic interactions between the hydrophobic tails.
[C] Decreased entropy of lipids.
[D] Hydrogen bonding and ionic interactions between the phospholipid head groups.
[E] Increased entropy of water.

Answer: E. Increased entropy of water.

Explanation:

Hydrophobic interactions are interactions between hydrophobic molecules and consist only of weak forces (van der Waals and London dispersion forces, induced dipole-induced dipole interactions). The spontaneous formation of bilayers results from the entropic aspect of thermodynamics, and not from these weak bonds. Lipids coalesce to reduce the amount of water surrounding its molecules, and thereby increasing entropy of water. This phenomenon results in the formation of essential components of life, such as the lipid bilayer membrane in eukaryotic cells.

Comments: (Your feedback is valuable to us)

DHRUBA CHARAN DUTTA 4 months ago Reply

very useful and interesting.


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