The following figure is a model of seedling establishment as a function of distance from a parent tree. Initial seed density measures the number of seeds falling to the ground. Seed survivorship measures the proportion of seeds that survive to the adult stage at each distance

Which of the following factors is most likely to generate the seed survivorship curve shown? 

#Question id: 10366

#Unit 6. System Physiology – Plant

Cyanobacteria can fixes nitrogen in an anaerobic conditions. Which of the following statements about heterocyst which is specialized cell of blue-green algae is incorrect?

#Question id: 10365

#Unit 6. System Physiology – Plant

Why the nitrogenase enzymes catalyzes the nitrogen fixation reaction only in microanaerobic or anaerobic conditions?

#Question id: 10364

#Unit 6. System Physiology – Plant

Which of the following is the most common type of symbiosis occurs between members of the plant family and soil bacteria?

#Question id: 10363

#Unit 6. System Physiology – Plant

Free living nitrogen fixing takes place as shown in the following;

             TYPE                                                                                       N-FIXING GENERA

A) Cyanobacteria (blue-green algae)                                        i) Bacillus

B) Aerobic                                                                                     ii) Clostridium

C) Facultative                                                                              iii) Anabaena

D) Anaerobic nonphotosynthetic                                            iv) Rhodospirillum

E) Anaerobic photosynthetic                                                     v) Azospirillum

 Which of the following combination of free living nitrogen fixing bacteria is correct?

#Question id: 10361

#Unit 6. System Physiology – Plant

The carbon skeleton for amino acids derives from 3-phosphoglycerate generated during glycolysis is called anaplueratic reaction. Generated amino acids from 3-PGA is that,

#Question id: 10360

#Unit 6. System Physiology – Plant

How much ATP require in the nitrogen fixation or conversion of ammonium assimilation in the system?