QUES: The brain generally forms a ring round the pharynx (throat), consisting of a pair of ganglia (local control centers) above and in front of the pharynx, linked by nerve cords either side of the pharynx to another pair of ganglia just below and behind it. The brains of polychaetes are generally in the prostomium, while those of clitellates are in the peristomium or sometimes the first segment behind the peristomium. In some very mobile and active polychaetes the brain is enlarged and more complex, with visible hindbrain, midbrain and forebrain sections. The rest of the central nervous system is generally "ladder-like", consisting of a pair of nerve cords that run through the bottom part of the body and have in each segment paired ganglia linked by a transverse connection. From each segmental ganglion a branching system of local nerves runs into the body wall and then encircles the body. However, in most polychaetes the two main nerve cords are fused, and in the tube-dwelling genus Owenia the single nerve chord has no ganglia and is located in the epidermis.
What is rarely "ladder-like"?

ANS: unanswerable

QUES: Archaeologist Louis Binford criticised the idea that early hominids and early humans were hunters. On the basis of the analysis of the skeletal remains of the consumed animals, he concluded that hominids and early humans were mostly scavengers, not hunters, and this idea is popular among some archaeologists and paleoanthropologists. Robert Blumenschine proposed the idea of confrontational scavenging, which involves challenging and scaring off other predators after they have made a kill, which he suggests could have been the leading method of obtaining protein-rich meat by early humans.
What group is the idea of humans being hunters popular with?

ANS: unanswerable

QUES: At least a few insects have nociceptors, cells that detect and transmit sensations of pain. This was discovered in 2003 by studying the variation in reactions of larvae of the common fruitfly Drosophila to the touch of a heated probe and an unheated one. The larvae reacted to the touch of the heated probe with a stereotypical rolling behavior that was not exhibited when the larvae were touched by the unheated probe. Although nociception has been demonstrated in insects, there is no consensus that insects feel pain consciously
Which probe did the larvae react to?

ANS: the heated probe

QUES: In 1902, the Siemens company developed a tantalum lamp filament. These lamps were more efficient than even graphitized carbon filaments and could operate at higher temperatures. Since tantalum metal has a lower resistivity than carbon, the tantalum lamp filament was quite long and required multiple internal supports. The metal filament had the property of gradually shortening in use; the filaments were installed with large loops that tightened in use. This made lamps in use for several hundred hours quite fragile. Metal filaments had the property of breaking and re-welding, though this would usually decrease resistance and shorten the life of the filament. General Electric bought the rights to use tantalum filaments and produced them in the US until 1913.
What lamps were less efficient than even graphitized carbon filaments?

ANS:
unanswerable