The signals flow from the chloroplast to the nucleus is retrograde:

plastidial ferrochelatase I catalyzes the synthesis of heme, which in turn regulates the expression of nuclear encoded, chloroplast‐targeted proteins in greening leaves.

TLS Online TPP Program

#Id: 4321

#Unit 11. Evolution and Behavior

Italian physician Francesco Redi (1626–1697),

His hypothesis was supported when maggots developed in the uncovered jars, but no

maggots appeared in either the gauze-covered or the tightly sealed jars. He concluded that

maggots could only form when flies were allowed to lay eggs in the meat, and that the

maggots were the offspring of flies, not the product of spontaneous generation.

TLS Online TPP Program

#Id: 4322

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 4323

#Unit 11. Evolution and Behavior

 Pasteur made a series of flasks with long, twisted necks (“swan-neck” flasks)

TLS Online TPP Program

#Id: 4324

#Unit 11. Evolution and Behavior

His design allowed air inside the flasks to be exchanged with air from the outside, but prevented the introduction of any airborne microorganisms, which would get caught in the twists and bends of the flasks’ necks.

TLS Online TPP Program

#Id: 4325

#Unit 11. Evolution and Behavior

If a life force besides the airborne microorganisms were responsible for microbial growth within the sterilized flasks, it would have access to the broth, whereas the microorganisms would not.

TLS Online TPP Program

#Id: 4326

#Unit 11. Evolution and Behavior

He correctly predicted that sterilized broth in his swan-neck flasks would remain sterile as long as the swan necks remained intact.