#Question id: 12960
#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: 11459
#Unit 7. System Physiology – Animal
Partial or complete loss of hearing (deafness) can
be caused by damage to the ________.
I) axons of the neurons associated with each hair cell
that carry information to the brain
II) hair cells (the sensory receptors) in the cochlea
III) tympanic membrane, or eardrum
#Question id: 22958
#Unit 5. Developmental Biology
#Question id: 5431
#Unit 8. Inheritance Biology
Plant having height 6 cm are allowed to cross with plant having height 2 cm , all F1 progeny having height uniform 4 cm were allowed selfing to produced F2 progeny in which 3 plant out of 8 having height 4 cm . what are number of polygene involve in that trait ?
#Question id: 5695
#Unit 8. Inheritance Biology
Triploids are usually autopolyploids. They arise spontaneously in nature, but they can be constructed by geneticists from the cross of a 4n (tetraploid) and a 2n (diploid). Triploids are characteristically sterile due to