Download HighFour General Sciences Round 6 Category B: Grades 6 – 8

HighFour General Sciences
Category B: Grades 6 – 8
Round 6
Tuesday, February 14, 2017
The use of calculator is not required.
Answer #1
Explanation:
A
The moon orbits the Earth once every 27.322 days. It also takes
approximately 27 days for the moon to rotate once on its axis. As a
result, the moon does not seem to be spinning but appears to observers
from Earth to be keeping almost perfectly still. Scientists call this
synchronous rotation.
Answer #2
Explanation:
A
To calculate the mass given the density and the volume, we use the
formula
. The mass of 2 m3 of clay bricks is
kg,
which is the lowest of the ones listed.
Answer #3
Explanation:
B
Reflection is when light bounces off an object. If the surface is smooth
and shiny, like glass, water or polished metal, the light will reflect at the
same angle as it hit the surface. This is called specular reflection.
Answer #4
Explanation:
D
In biology and ecology, extinction is the end of an organism or of a group
of organisms (taxon), normally a species. The moment of extinction is
generally considered to be the death of the last individual of the species,
although the capacity to breed and recover may have been lost before
this point.
Answer #5
Explanation:
C
In 1875, the trench was discovered by the HMS Challenger using recently
invented sounding equipment during a global circumnavigation. In 1951,
the trench was sounded again by HMS Challenger II. In 1960, a "deep
boat" named Bathyscaphe Trieste reached the bottom of Challenger
Deep.
HighFour General Sciences
Category B: Grades 6 – 8
Round 6
Tuesday, February 14, 2017
The use of calculator is not required.
Answer #6
Explanation:
B
Plants use energy from sunlight to turn water and carbon dioxide into an
energy-rich sugar called glucose. This process is called photosynthesis,
which means “making things with light”. Photosynthesis takes place
inside capsules in the leaf cells, called chloroplasts.
Answer #7
Explanation:
C
Aquatic plants are plants that have adapted to living in aquatic
environments (saltwater or freshwater). They are also referred to as
hydrophytes or macrophytes. These plants require special adaptations
for living submerged in water, or at the water's surface.
Answer #8
Explanation:
A
The muscular system is responsible for the movement of the human
body. Attached to the bones of the skeletal system are about 700 named
muscles that make up roughly half of a person's body weight. Each of
these muscles is a discrete organ constructed of skeletal muscle tissue,
blood vessels, tendons, and nerves.
Answer #9
Explanation:
B
The lithosphere is the solid, outer part of the Earth. The lithosphere
includes the brittle upper portion of the mantle and the crust, the
outermost layers of Earth's structure. It is bounded by the atmosphere
above and the asthenosphere (another part of the upper mantle) below.
Answer #10
Explanation:
D
Non-renewable energy comes from sources that will run out or will not
be replenished in our lifetimes—or even in many, many lifetimes. Most
non-renewable energy sources are fossil fuels: coal, petroleum, and
natural gas. Carbon is the main element in fossil fuels.
HighFour General Sciences
Category B: Grades 6 – 8
Round 6
Tuesday, February 14, 2017
The use of calculator is not required.
Answer #11
Explanation:
D
Fertilization is the process by which a sperm cell and an egg cell unite to
form a completely new individual. The difference between internal and
external fertilization is that internal fertilization occurs inside the body,
whereas external fertilization happens outside the body. In mammals,
reptiles, birds, and some types of fish the gametes meet inside of the
female's body.
Answer #12
Explanation:
B
Genetic engineering, also called genetic modification, is the direct
manipulation of an organism's genome using biotechnology. It is a set of
technologies used to change the genetic makeup of cells, including the
transfer of genes within and across species boundaries to produce
improved or novel organisms.
Answer #13
Explanation:
B
Drilling began on May 24th, 1970 in the Kola Peninsula and continued
breaking records of all sorts. Many holes were drilled branching from the
center. The deepest of these holes is the hole SG-3, which reached a
depth of 12,262 meters (more than 40,000 ft) in 1989.
Answer #14
Explanation:
D
During the process of absorption, nutrients that come from the food
(including carbohydrates, proteins, fats, vitamins, and minerals) pass
through channels in the intestinal wall and into the bloodstream. The
blood works to distribute these nutrients to the rest of the body.
Answer#15
Explanation:
A
Objects have mechanical energy if they are in motion and/or if they are
at some position relative to a zero potential energy position (for
example, a brick held at a vertical position above the ground or zero
height position). A moving car possesses mechanical energy due to its
motion (kinetic energy).
HighFour General Sciences
Category B: Grades 6 – 8
Round 6
Tuesday, February 14, 2017
The use of calculator is not required.
Answer #16
Explanation:
A
Sandstone (sometimes known as arenite) is a clastic sedimentary rock
composed mainly of sand-sized minerals or rock grains. Most sandstone
is composed of quartz or feldspar because these are the most common
minerals in the Earth's crust.
Answer #17
Explanation:
C
Galaxies are divided into four main groups: spiral, barred spiral, elliptical,
and irregular. Spiral Galaxy – Spiral galaxies are characterized by a
distinct flattened spiral disk with a bright center called the nucleus. Our
own Milky Way is a spiral galaxy.
Answer #18
Explanation:
B
A unicellular organism, also known as a single-celled organism, is an
organism that consists of only one cell, unlike a multicellular organism
that consists of more than one cell. The main groups of unicellular
organisms are bacteria, archaea, protozoa, unicellular algae, and
unicellular fungi. Unicellular organisms fall into two general categories:
prokaryotic organisms and eukaryotic organisms.
Answer #19
Explanation:
B
Galileo Galilei is commonly credited for inventing the telescope, but this
is not accurate. Galileo was the first to use a telescope for the purpose
of astronomy in 1609, although the earliest known working telescopes
appeared in 1608 in the Netherlands and are credited to Hans
Lippershey.
Answer #20
Explanation:
D
Sedimentary rocks are types of rock that are formed by the deposition
and subsequent cementation of that material at the Earth's surface and
within bodies of water. Sedimentation is the collective name for
processes that cause mineral and/or organic particles (detritus) to settle
in place.