#Question id: 12098
#Unit 10. Ecological Principles
The herbaceous plant Achillea lanulosa is widespread in the Northern Hemisphere. Phenotypic variation in the species has been extensively studied along an altitudinal gradient from sea level to over 3,000 meters. In California there is conspicuous variation in height; alpine plants are only several centimeters tall while those in the San Joaquin Valley may reach a height of 1.8 meters. Adaptation to different local environments also results in variation in physiological processes such as photosynthetic rate, resistance to cold, and the timing of dormancy.
The morphological variation shown by Achillea lanulosa illustrates
#Question id: 203
#Unit 1. Molecules and their Interaction Relevant to Biology
#Question id: 23583
#Unit 13. Methods in Biology
#Question id: 2350
#Unit 2. Cellular Organization
The maximum size of cells is _____
#Question id: 5281
#Unit 8. Inheritance Biology
In the mating Hfr Strs met+ his+ leu+ trp+ Ala+ X F- Strres met- his- leu- trp- Ala-. At regular interval time, the mating cells are interrupted and the cell suspensions plated on four different growth media with streptomycin. The amino acids in the growth media and the number of colonies observed on each are as follows:
Interrupted time |
Composition of media |
Growth |
||||
His |
Leu |
Ala |
Trp |
Met |
||
2 min |
+ |
- |
+ |
+ |
+ |
Yes |
10 min |
+ |
- |
- |
+ |
+ |
Yes |
12 min |
+ |
- |
- |
+ |
- |
No |
15 min |
+ |
- |
- |
- |
+ |
Yes |
20 min |
- |
- |
- |
- |
+ |
Yes |
What is the order of transfer of the genes?