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TLS Online TPP Program

#Question id: 10899

Companion cells transport of photosynthetic products from producing cells in mature leaves to the sieve elements in the minor veins of the leaf. There are at least three different types of companion cells in the minor veins of mature, exporting leaves, All three cell types have dense cytoplasm and abundant mitochondria;

#Unit 6. System Physiology – Plant
  1. transfer cells, tonoplast cell, and Xylem parenchyma
  2. ordinary companion cells,  transfer cells,  and intermediary cells
  3. tapered lignified cell, ordinary cell, and intermediary companion cells
  4. tonoplast cell, phloem parenchyma and ordinary companion cells
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TLS Online TPP Program

#Question id: 12342

#Unit 10. Ecological Principles

Which of the following is a biological attribute that would most likely allow a species to become cosmopolitan in distribution?
TLS Online TPP Program

#Question id: 12343

#Unit 10. Ecological Principles

Hybrids between some related species of plants are sterile because the parent plants had different chromosome numbers. Occasionally the chromosome number of such a hybrid  plant doubles spontaneously. Which of the following best describes the descendants of those plants with the double chromosome number?
TLS Online TPP Program

#Question id: 12344

#Unit 10. Ecological Principles

The concept of punctuated equilibrium refers to
TLS Online TPP Program

#Question id: 12345

#Unit 10. Ecological Principles

Shannon's index of diversity is calculated using the equation below, where pi is the proportion of the ithShannon's index of diversity is calculated using the equation below, where pi is the proportion of the ith species and ln is natural logarithm. For a community with a given number of species, which of the following statements is true? species and ln is natural logarithm. For a community with a given number of species, which of the following statements is true?
TLS Online TPP Program

#Question id: 12346

#Unit 10. Ecological Principles

The schematic below shows the relationship between survivorship with age (relative to maximum lifespan) in Species 1 (dashed line) and Species 2 (solid line). Which of the following inferences is compatible with this figure?
TLS Online TPP Program

#Question id: 12347

#Unit 10. Ecological Principles

A team of conservation biologists, surveying a population of frogs on an island, captured and marked 312 individuals in the first sample. In a second sampling, 3 days later, the team caught 140 individuals of which 26 were previously marked. The total number of frogs on the island is estimated to be . (Use decimal notation, not fractions or percentage)