The TTL output stage is a rather complicated pushâpull circuit known as a totem-pole output (the transistors, diode, and resistor in the right-most slice of this TTL logic gate circuit). It sinks currents better than it sources current.
The theory for spontaneous generation refers to the idea that life can produced from nonliving things. Lazzaro Spallanzani proposed in his experiement that air was necessary for spontaneous generation.
Lazzaro Spallanzani. Italian physiologist who disproved the theory of spontaneous generation (1729-1799), disproved the theory of spontaneous generation with the 1st broth experiment- showed that microorganisms contaminated the boiled broth only when the flask containing the broth was left open to the air. this showed that microorganisms did not come from the broth but from the air