Download HighFour Biology Round 2 Category C: Grades 9 – 10 Tuesday

HighFour Biology
Category C: Grades 9 – 10
Round 2
Tuesday, October 13, 2015
The use of calculator is not required.
Answer #1:
Explanation:
vestigial/rudimentary organs
Vestigial/rudimentary organs are structures that have lost some or all of
their ancestral functions. Examples of which are the hind limb and pelvic
girdle bones of whales and snakes, and the coccygeal tail vertebrae and
vermiform appendix of humans.
Answer #2:
Explanation:
Louis Pasteur
Louis Pasteur first discovered the use of heat in food preservation, a
process called pasteurization, when the heating of beer and wine resulted
to the prevention of spoilage. Pasteurization is different from sterilization,
in that the former is only capable of killing a fraction of the microorganisms
present with only marginal changes in the property of the food.
Answer #3:
Explanation:
micelle
One of the stable configurations of phospholipids is a micelle. A micelle
could be formed from the aggregation of hydrophobic groups in the center
and the exposure of the hydrophilic groups outside of a phospholipid
sphere.
Answer #4:
Explanation:
zygote
A zygote is formed when a sperm fertilizes an egg. Having all the necessary
genetic information for early development, the zygote eventually becomes
a multicellular structure with increased complexity.
HighFour Biology
Category C: Grades 9 – 10
Round 2
Tuesday, October 13, 2015
The use of calculator is not required.
Answer #5:
Explanation:
extinct species
According to the International Union for Conservation of Nature (IUCN), a
species is said to be extinct when an individual belong to the said taxon can
no longer be found in wild or captivity.
Answer #6:
Explanation:
nitrogen fixation
Nitrogen fixation is the initial step of the nitrogen cycle. It is carried out by
nitrogen-fixing organisms, such as the aerobic Azotobacter, the anaerobic
Desulfovibrio, and the Rhizobium found in association with root nodules of
legumes.
Answer #7:
Explanation:
competition
A competition is more typically defined as the interaction between
individuals vying for a common resource. Competition can also be
described as the direct or indirect interaction of individuals which results to
the lowering of the fitness of one due to another.
Answer #8:
Explanation:
0-10 hours
The number of a population at a time is different from the change in the
number of the population during a period. Although the population was at
the peak between 50-60 hours, the population growth was at its most
drastic between 0-10 hours, having exhibited a population change of 400
(400 [at the 10-hr mark] minus 0 [at the 0-hr mark]).
HighFour Biology
Category C: Grades 9 – 10
Round 2
Tuesday, October 13, 2015
The use of calculator is not required.
Answer #9:
Explanation:
pyramid of numbers / number pyramid
The pyramid of numbers is distinct from the pyramids of energy and
biomass, in that it depicts the number of organisms in an ecosystem, with
increasing trophic levels beginning from the bottom. The appearance of the
pyramid of numbers varies from ecosystem to ecosystem.
Answer #10:
Explanation:
0.6%
The percentage of energy transferred from the sunlight to the green plants
can be calculated by dividing the energy harnessed by the green plants by
the energy contained in sunlight:
24 000 𝑘𝑘𝑘𝑘 𝑚𝑚−2
× 100 = 0.6%
4 000 000 𝑘𝑘𝑘𝑘 𝑚𝑚−2
Answer #11:
Explanation:
Dmitri Ivanovsky
Dmitri Ivanovsky first noted the existence of viruses (in particular, the
tobacco mosaic virus) when he mashed up tobacco mosaic disease-infected
leaves and the resulting fluid was passed through ceramic filters supposedly
able to strain the tiniest of bacteria. The filtered fluid was still able to infect
healthy tobacco plants with the disease, indicating the presence of a novel
infectious agent.
Answer #12:
Explanation:
septate / septate hypha
A septate hypha is divided into compartments, such as that shown in the
image. The dividing walls within the hypha are called the septa.
HighFour Biology
Category C: Grades 9 – 10
Round 2
Tuesday, October 13, 2015
The use of calculator is not required.
Answer #13:
Explanation:
ostia/ostium
Each pore along the body of sponges through which water flows in for
feeding is called the ostia (plural: ostium). Filtered water is expelled from
sponges through the osculum.
Answer #14:
Explanation:
Eukarya / Eukaryota
Organisms under the Kingdom Plantae are all multicellular eukaryotes. All
eukaryotes belong to the domain Eukarya / Eukaryota.
Answer #15:
Explanation:
orange cosmos plant (Cosmos sulphureus)
A pioneer species is the first species to colonize and occupy a place where
there are no previous living organisms. In this scenario, the pioneer species
of a portion of the forest is the orange cosmos plant (Cosmos sulphureus).
Answer #16:
Explanation:
taiga / boreal forest
The taiga / boreal forest biome is situated between 50 to 70 degrees
latitude north. The primary flora populating this biome are coniferous trees
because of the terrestrial, sub-artic, and humid environment.
HighFour Biology
Category C: Grades 9 – 10
Round 2
Tuesday, October 13, 2015
The use of calculator is not required.
Answer #17:
Explanation:
Chilopoda
Aves (birds), Chondrichthyes (cartilaginous fishes), and Reptilia (reptiles)
are all classes under the phylum Chordata. All of them possess a notochord
and a nerve cord. On the other hand, Chilopoda (centipedes) belongs to the
phylum Arthropoda.
Answer #18:
Explanation:
binomial nomenclature
The binomial nomenclature system is a formal system of assigning an
unambiguous name, which consists of a genus and a specific epithet, for
each species. For example, the onion has a scientific name of Allium cepa.
The first part of the name (Allium) corresponds to the genus, whereas the
second name (cepa) represents the specific epithet.
Answer #19:
Explanation:
crista / cristae
The arrow is pointing to the crista, which is a fold in the inner membrane of
the mitochondria. The cristae give the characteristic wrinkled shape of the
cross-section of the inner membrane of the mitochondria when viewed
under the microscope.
Answer #20:
Explanation:
cytoskeleton
The cytoskeleton is a crucial component in the maintaining the shape and
rigidity of cells. It is constituted of several components, namely actin,
microtubules, and intermediate filaments—each of which has unique
functions to the health of cells.