A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (i.e., halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition could have

#Question id: 10358

#Unit 6. System Physiology – Plant

Which of the following essential micronutrients is associated with nitrate reductase enzyme found in higher plants?

#Question id: 10359

#Unit 6. System Physiology – Plant

Nitrate reductases of higher plants are composed of two identical subunits, each containing three prosthetic groups. Which of the following is not the prosthetic group of nitrate reductase;

#Question id: 10362

#Unit 6. System Physiology – Plant

Bacteria can convert atmospheric nitrogen into ammonia, Several form symbiotic associations with higher plants is given below;

               HOST PLANT                                                                          N-FIXING SYMBIONTS

A) Gunnera                                                                            i) Frankia

      B) Azolla                                                                                ii) Acetobacter

C) Leguminous                                                                     iii) Azospirillum

             D) Actinorhizal                                                                      iv) Nostoc

             E) Sugarcane                                                                         v) Anabaena

             F) Miscanthus                                                                       vi) Sinorhizobium

Which of the following combination with the host plants and n-fixing symbionts is CORRECT?

#Question id: 10368

#Unit 6. System Physiology – Plant

Free-living bacteria that are capable of fixing nitrogen are aerobic, facultative, or anaerobic. Some of the Aerobic nitrogen-fixing bacteria such as

#Question id: 10369

#Unit 6. System Physiology – Plant

Which type of the nitrogen-fixing bacteria are thought to maintain a low oxygen concentration (microaerobic conditions) through their high levels of respiration

#Question id: 10370

#Unit 6. System Physiology – Plant

Rhizobial genes that participate in nodule formation are called nodulation (nod) genes. Only one of the nod genes, the regulatory and constitutively expressed and regulates the transcription of the other nod genes;