Practice Questions

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#Question id: 12958

The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years
Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

Fitness is a measure of the reproductive success of a particular genotype. The highest fitness is 1.00.
The strong dependence of RR individuals on large quantities of vitamin K probably is responsible for

#Unit 10. Ecological Principles

Their lowered fitness
Their susceptibility to warfarin
Their superiority to heterozygotes (Rr)
Their increasing numbers in the population each generation

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TLS Online TPP Program

#Question id: 19104

#Unit 6. System Physiology – Plant

The structural components of the T3SS are encoded by the clustered gene known as

TLS Online TPP Program

#Question id: 19105

#Unit 6. System Physiology – Plant

The type III secretion system (T3SS), to deliver bacterial effector proteins into the plant cell have been identified to be secretion of enzymes which causes dead of the plant, these enzymes are;

a) Phosphatases

TLS Online TPP Program

#Question id: 1016

#Unit 6. System Physiology – Plant

Lyme disease is an example of a disease

TLS Online TPP Program

#Question id: 13200

#Unit 6. System Physiology – Plant

In the modification of translocation pathways, Interference with a translocation pathway by wounding or pruning can alter the patterns established by proximity and vascular connections. In the absence of direct connections between source and sink, vascular interconnections, called

TLS Online TPP Program

#Question id: 13198

#Unit 6. System Physiology – Plant

The sugar is a carbohydrate that are generally translocated in the phloem in which form?

TLS Online TPP Program

#Question id: 11806

#Unit 6. System Physiology – Plant

sap is translocated from areas of supply, called sources, to areas of metabolism or storage, called sinks. Which of the following statements about source and sink are TRUE?

a.) Sinks include any nonphotosynthetic organs of the plant and organs that do not produce enough photosynthetic products to support their own growth or storage needs

b.) Sources include exporting organs that are capable of producing photosynthate in excess of their own needs

c.) During the growing season of the first year, storage root is a sink, when it accumulates sugars received from the source leaves. During the second growing season the same root becomes a source

d.) Roots, tubers, developing fruits, and immature leaves, which must import carbohydrate for normal development, are all examples of sources tissues

Find the correct combination of the source and sink pattern of translocation.