Download HighFour Biology Round 8 Category D: Grades 11 – 12 Friday, April

HighFour Biology
Category D: Grades 11 – 12
Round 8
Friday, April 22, 2016
The use of calculator is not required.
Answer#1:
Explanation:
adrenal gland
The adrenal glands are small glands located on top of the kidney. The
adrenal cortex secretes steroid hormones that help maintain homeostasis
during long-term stress, whereas the adrenal medulla secretes epinephrine
and norepinephrine in response to nerve signals triggered by short-term
stress.
Answer #2:
Explanation:
florigen
Florigen is the hypothetical hormone-like molecule responsible for
flowering in plants. Until now, the exact nature of florigen remains
unknown.
Answer #3:
Explanation:
Shannon Diversity Index
The Shannon Diversity Index is an index of community diversity symbolized
by H and calculated using the relative abundance of the species in the
community. A higher value of H indicates a more diverse community.
Answer #4:
Explanation:
proton pump
The proton pump is an active transport protein that utilizes adenosine
triphosphate (ATP) to transport hydrogen ions against their concentration
gradient, a process which generates membrane potential.
Answer #5:
Explanation:
3/ three
The circular DNA has three restriction sites for EcoRI. As a result, digestion
with EcoRI will produce three fragments.
HighFour Biology
Category D: Grades 11 – 12
Round 8
Friday, April 22, 2016
The use of calculator is not required.
Answer #6:
Explanation:
methanogen
Methanogens are organisms that produce methane as a waste product of
the process by which they obtain energy. All known methanogens belong to
the domain Archaea.
Answer #7:
Explanation:
high-density lipoprotein (HDL)
High-density lipoprotein or HDL is a particle in the blood that is made up of
several cholesterol molecules and other lipids bound to a protein. HDL
scavenges excess cholesterol and returns it to the liver. Individuals with
high ratio of LDL to HDL are more at risk for heart disease.
Answer #8:
Explanation:
sclerenchyma cells
Sclerenchyma cells are specialized for support and strengthening. They can
be subdivided into two types, namely sclereids and fibers. Sclereids bestow
hardness to nutshells and seed coats, whereas fibers are typically grouped
in strands, such as in hemp fibers.
Answer #9:
Explanation:
serotonin
Serotonin is a neurotransmitter released at many sites in the brain. It is
involved in sleep, mood, attention, and learning.
Answer #10:
Explanation:
law of independent assortment
The law of independent assortment is applicable when genes for two
characters are located on different pairs of homologous chromosomes or
when they are far apart enough on the same chromosome.
HighFour Biology
Category D: Grades 11 – 12
Round 8
Friday, April 22, 2016
The use of calculator is not required.
Answer #11:
Explanation:
ectoderm
The ectoderm is the outermost of the three primary germ layers in animal
embryos. It gives rise to the outer covering of the animal, and in some
phyla, to the central nervous system.
Answer #12:
Explanation:
sickle-cell disease
Sickle-cell disease is a recessively inherited human blood disorder caused
by a single nucleotide change in the β-globin gene. As a result, red blood
cells assume a sickle shape, causing multiple symptoms in afflicted
individuals.
Answer #13:
Explanation:
peptide bond
Peptide bond is the covalent bond that connects amino acids to form
polypeptides. Extending from the polypeptide backbone are the different
side chains (R groups) of amino acids.
Answer #14:
Explanation:
electrocardiogram (ECG or EKG)
An electrocardiogram is the record of the currents that travel through the
heart muscle. The characteristic shape of ECG graphs is generated from the
different stages in the cardiac cycle.
Answer #15:
Explanation:
gel electrophoresis
Gel electrophoresis is a technique for separating nucleic acids or proteins
according to their sizes and electrical charges through an electric field in a
gel made of polymer.
HighFour Biology
Category D: Grades 11 – 12
Round 8
Friday, April 22, 2016
The use of calculator is not required.
Answer #16:
Explanation
interferons
Interferons are proteins with antiviral or immune regulatory functions.
They belong to the larger group of glycoprotein cytokines secreted by host
lymphocytes. The activation of interferons ultimately leads to the clearance
of the pathogen or tumor cells from the organism.
Answer #17:
Explanation:
P site / peptidyl-tRNA binding site
The P site or the peptidyl-tRNA binding site holds the tRNA which carries
the growing polypeptide chain. During the initiation of translation, the P
site holds the initiator tRNA for Met.
Answer #18:
Explanation:
utricle and saccule
The chambers called utricle and saccule participate in the sense of balance
and open into the three semicircular canals. They contain a sheet of hair
cells that project into a gelatinous material with many small calcium
carbonate particles embedded onto it.
Answer #19:
Explanation:
leptin
Leptin acts as a satiety factor in regulating appetite. The exact nature of
leptin remains unknown. For instance, it has complex functions, including in
the development of the nervous system. It also apparently fails in eliciting a
response from the brain’s satiety center when present in abnormally high
amounts.
Answer #20:
Explanation:
rhodopsin
Rhodopsin is the visual pigment of rods. It consists of both retinal and
opsin. As light is absorbed by rhodopsin, the retinal changes shape and
dissociates from the opsin.