Chapter 29, Problem 9TYPSS

Summary Introduction

To review:

Koch’s postulates and design the study using Koch’s postulates to test the hypothesis that chytrid infections are responsible for the frog deaths.

Introduction:

Koch’s postulates state that the microorganism must be present in all the diseased individuals, but it must be absent in the healthy organism. The table mentioning that the chytrids are responsible for massive die-offs occurring in amphibians is given below:

Fungi	Known species	Absorptive lifestyle	Life cycle	Relevance
Chytrids (common in freshwater)	750	Many decompose the plants by digesting the cellulose. Mutualistic chytrids reside in the guts of deer, cows, and other mammals and help in the digestion of plant material. Parasitic chytrids infect many plant and animal species	These are the only fungi that produce motile cells—both their gametes and spores through flagella. Most exhibit alteration of generations.	Some are parasites of mosquitos. Batrachochytrium dendrobatidis is mainly responsible for the decline in the populations of amphibians worldwide.