There are several information's of immense importance already given in the question. Based on those information's the answer can be easily deduced.
Initial number of bacteria in the culture = 1000
Number of bacteria after t hours = 1000 (2)^t
Then
1000 (2)^t = 50000
2 ^t = 50
t = 5.6
I hope the procedure is clear enough for you to understand.
1. Cellular respiration does not consume carbon dioxide (CO2).
Cellular respiration is a process by which plants produce energy. It consists of anaerobic (without O2) and aerobic phase(with the presence of O2). During the cellular respiration chemical energy derived from the nutrients (like glucose) is transformed into energy molecule adenosine triphosphate (ATP).
2. Unlike photosynthesis, cellular respiration occurs in all eukaryotic organisms (photosynthesis only in plants and some microorganisms). The processes of cellular respiration occur in cytosol (glycolysis) and in the mitochondrion of a cell (Krebs cycle and electron transport chain).
Explanation:
a iv
b viii
c ii
d i
e iii
g i
f. single cotyledon it's v
two cotyledon it's vi