What are “dog days”?

“Dog days” are the hot, humid days of summer that usually take place in the Northern Hemisphere in July and August typically between July 3 and August 11. The days get their name from the dog star Sirius of the constellation Canis Major.

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At this time of year, Sirius, the brightest visible star, rises in the east at the same time as the Sun in the northern hemisphere. Ancient Egyptians believed that the heat of this brilliant star added to the Sun’s heat to create this hot weather and they blamed the star for everything from withering droughts to sickness.

Would it hurt if a plant-eating dinosaur bit you?

Absolutely. Being bitten by a plant-eating dinosaur such as Brachiosaurus, with its 52 chisel-like teeth, would certainly hurt! The bite of a Parasaurolophus, with its interlocking rows of teeth, might take off your fingers. In the Iguanodon, numerous sharp teeth were set in rows in the upper and lower jaws, and at steep angles to each other.

When the teeth were pressed together, the upper jaw was forced outward, creating a grinding motion between the teeth and its meal of crushed plant tissue.

What’s a cobweb?

A cobweb is an old, abandoned spider web that has collected dirt and dust. Sometimes the cobwebs you see in ceiling crevices and along floorboards are several draglines that spiders no longer use.

The common house spider—which feeds on many insects daily—often abandons webs that do not yield prey, and then constructs new ones until it finds a productive site. It’s best to sweep these old cobwebs away, and let your house spiders spin new webs, preferably outdoors!

What Polygraph instrument does?

Instrument that simultaneously records changes in physiological processes such as heartbeat, blood pressure and respiration used as a lie detector

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When wood burns it crackles. Explain?

Wood contains a complex mixture of gases and tar forming vapors trapped under its surface. These gases and tar vapors escape, making a cracking sound.

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Are there plants that do not grow from seeds?

Yes. Not all plants are seed plants. Some plants, such as ferns and mosses, reproduce with spores instead of seeds. Spores, like seeds, can survive harsh conditions and develop into new plants. However, unlike seeds, spores are produced without fertilization and contain neither a plant embryo nor endosperm. Some plants can reproduce without spores or seeds through vegetative reproduction, in which a part of the stem or root gives rise to a new plant.

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