The biosynthesis of gibberellins is under strict genetic, developmental, and environmental control, and numerous gibberellin-deficient mutants have been isolated.  Mendel’s tall/dwarf alleles in peas are a famous example. Such mutants have been useful in elucidating the complex pathways of gibberellin biosynthesis.

TLS Online TPP Program

#Id: 5372

#Unit 10. Ecological Principles

Baited snap traps, Population density can thus be estimated as the number of animals caught per trap or per unit area where a given number of traps are set.

TLS Online TPP Program

#Id: 5373

#Unit 10. Ecological Principles

The mark-recapture technique is that after the tagged animals are released, they mix freely with unmarked individuals. The population is resampled and the numbers of marked and unmarked individuals are recorded. 

TLS Online TPP Program

#Id: 5374

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 5375

#Unit 10. Ecological Principles

Mark-recapture technique can have drawbacks;

1. Some animals that have been marked may learn to avoid the traps. 
2. Recapture rates will then be low, resulting in an overestimate of population size.

TLS Online TPP Program

#Id: 5376

#Unit 10. Ecological Principles

Some animals can become trap-happy, particularly if the traps are baited with food. This would result in an underestimate of the population size.

TLS Online TPP Program

#Id: 5378

#Unit 10. Ecological Principles

Clumped: The most common dispersion pattern is clumped, because resources tend to be clustered in nature.