Where do seedless grapes come from?
Most commercial fruit isn’t grown from seed.
Even fruits that still have seeds, like apples and
cherries, are grown from cuttings because this
guarantees that the plant will be genetically
identical to the parent plant from which they
are cloned. Seedless grapes were originally
a natural mutation that prevented the young
seeds from maturing and developing a
hard coat. And even seedless varieties do
sometimes produce small numbers of
seeds, which allows new varieties to be
crossbred. LV
There is a lot of variation in temperature throughout the Universe. The
coldest naturally occurring temperature was discovered inside the
Boomerang Nebula and is only one degree above absolute zero. The hottest
temperatures (not including the Big Bang itself) are likely to be generated in
the interactions that create so-called gamma-ray bursts.
But what about the average temperature of the Universe? Astronomers often
regard the temperature of the Cosmic Microwave Background (CMB) as the
temperature of the Universe. The CMB is a snapshot of the oldest light in the
Universe, imprinted on the sky when the Universe was just 380,000 years
old. It has a temperature of just 2.735 degrees above absolute zero. The Big
Bang theory predicts that as the Universe expands this temperature should
drop. This is what astronomers have found by deducing the temperature of
the CMB at various distances across the Universe. AG
Does the temperature of the Universe change
with time?