#Question id: 10917
#Unit 6. System Physiology – Plant
Photosynthetic sugar molecules are transported via phloem to other parts of the plants. The following aspects are associated with sucrose unloading in phloem and its transport;
a) The presence of plasmodesmata is assumed to provide apoplastic transport. An absence of plasmodesmata between cells indicates an nonfunctional symplastic continuity
b) Phloem unloading and short-distance transport can occur via symplastic as well as apoplastic pathways
c) Both unloading and the short-distance pathway appear to be completely symplastic in some young eudicot leaves, such as sugar beet and tobacco
d) An apoplastic step is required in developing seeds because there are no symplastic connections between the maternal tissues and the tissues of the embryo
Which of the following combination is INCORRECT?
#Question id: 12759
#Unit 10. Ecological Principles
#Question id: 19734
#Unit 3. Fundamental Processes
#Question id: 13142
#Unit 10. Ecological Principles
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.
#Question id: 12308
#Unit 7. System Physiology – Animal