INTRODUCTION TO BIOLOGY PROCTORED EXAM | PENN FOSTER
INTRO TO BIOLOGY PROCTORED FINAL EXAM WITH QUESTIONS
AND ANSWERS SELF ASSESSMENT GUIDE GRADED A+ 2024 - PENN
FOSTER
Explain the elements necessary for a controlled experiment, what’s the controlled group and what's
the experimental group what variables are explain the difference between controlled variables
manipulated variables and responding variables in a well-designed experiment.
A controlled experiment requires a control group which doesn’t receive the experimental treatment and an
experimental group which does receive experimental treatment besides experimental treatment all other
conditions are kept the same variables are the factors that can influence the outcome of an experiment
controlled variables don't change and are the same between the control group and the experimental group
manipulated or independent variables are intentionally changed and experimental group responding
variables are the result of the change in experimental group
Compare and contrast a nonpolar covalent bonds and a polar covalent bonds how are these bonds
formed. How are the electrons distributed in the molecules of these bonds give an example of each
type of these bonds
A nonpolar and a polar covalent bond are both types of covalent bonds which are formed through two
atoms sharing electrons and both types of bonds these shared electrons typically filled the outermost shell
of the electrons. In polar covalent bonds the electrons are not shared equally between two atoms. one of
the atoms Is more electronegative then the other so one end of the bond develops a partial negative
charge and the other end of the bond develops a partially positive charge. The bonds between hydrogen
and oxygen and water provide a good example of a polar covalent bond. In nonpolar covalent bonds the
electrons are shared equally it's between the two atoms so no partial charges are formed. A good example
of a non polar covalent bond is the bond between oxygen atoms in a molecule of oxygen gas O2 or the
bond between chlorine atoms in the molecule of chlorine gas CL2.
Outline structure proteins. Describe the monomers that make up proteins and define the
differences between proteins peptides and polypeptides. Explain the four levels of protein structure
from primary to quaternary protein structure.
Proteins are polymers of amino acids which are molecules that have both an amine and a carboxyl
function group attached to a alpha carbon. Organisms. Typically use 20 amino acid to build proteins.
Peptides are short changes of amino acids. Polypeptides are long chains of polypeptides and proteins can
be formed from one or several peptide chains.
The primary Structure of a protein is its amino acid structure. The secondary structure of a protein. Is
how hydrogen bonding. Between amino acids and a protein form local structures such as alpha helices and
beta sheet
The tertiary structures of a protein is how it exists in three dimensions, and the quaternary structure of a
protein is how multiple polypeptide chains interact with each other to form a functional protein.
Name three organelles unique eukaryotes and describe their functions.
The nucleus stores cellular DNA and direct cellular activity by controlling DNA transcription and
synthesis.The smooth endoplasmic reticulum doesn’t have ribosomes on its surface or has very few. Its
function is to synthesize lipids.The Golgi apparatus processes and packages the proteins and lipids
introduced by the endoplasmic reticulum.Mitochondria are responsible for carrying out cellular
respiration and thereby produce energy for the cell in the form of ATP.
,Lysosomes breakdown damaged cellular materials and salvage useful scraps of cellular material to be
reused.
Describe how an Organism responds to environmental stimuli to maintain a dynamic equilibrium
near a set point using a negative feedback loop. Give an example of a feedback loop to maintain
homeostasis.
Organisms function best with internal conditions near a specific value called the set point. This might be
an ideal body temperature, blood sugar level, or other value. Environmental changes, called stimuli,
cause the value to move away from the set point. On a cold day, the Organism is too cold or after eating
blood sugar spikes. The body then uses a negative feedback loop to move the value back towards a set
point and maintain homeostasis.A negative feedback loop is a process that changes the direction of or
reduces the stimuli. With the example of increased blood sugar after eating, the feedback loop works to
decrease blood sugar until homeostasis near the set point is restored.
Distinguish between a stem cell and a red blood cell. What’s the level of potency in each of these
cells? What’s the function of each of these cells?
A stem cell has a high level of potency because it’s undifferentiated or only partially differentiated. The
function. A stem cells is to differentiate into specialized cells and generate new cells to repair worn or
injured tissues. Red blood cells are unipotent and fully differentiated. Their functions is to transport
oxygen and carbon dioxide in the blood, and their structures is optimized for them to reform gas
exchange and flow through blood vessels.
Explain the function of enzyme ribulose bisphosphate carboxylase, also called RuBisCO. What
reaction does this enzyme catalyze, and why is this important?
RuBisCO catalyze carbon fixation in plants where carbon dioxide is added to A 5 carbon molecule to
form 2 3 carbon molecules. 1. 5 biphosphate and 3-carbon molecules formed by the reaction are
glyceraldehyde 3-phosphate. This is a step in the Calvin cycle, which are the light independent reactions
in photosynthesis. This is important because carbon fixation is how atmospheric carbon dioxide is
converted into sugars.
Compare. And contrast two types of cellular respiration. Please highlight the similarities between
these processes as well as their differences. What’s the final electron acceptor in each process?
Which process is more efficient?
Cellular respiration can be aerobic or anaerobic. Both types use of respiration use glucose to produce
energy in the form of ATP. Both types of respiration begin with glycolysis taking place in the cytoplasm,
but diverge after the PYRUVATE Is formed. PYRUVATE Acts as the final electron acceptor in the
cytoplasm in anaerobic respiration while it is transported to the mitochondria for the remainder of the
aerobic respiration.Aerobic respiration requires oxygen as the final electron acceptor, and it is much more
efficient. The starting materials for aerobic respiration are oxygen and glucose, and the final product Are.
Carbon dioxide. Water and ATP.Anaerobic respiration works in the absence of oxygen using.
PYRUVATE. As the final electron acceptor. The starting material for anaerobic respiration is glucose.
And the final products are ATP and lactic acid or ethanol.
,Our cell cycle checkpoints. What’s the function of a cell cycle checkpoint and the cell cycle
regulators?
Checkpoints are ways to sell minimizes the risk of an error being introduced during the cell cycle and
propagated to future generations of the cell. At the G1 checkpoint, cells must be ready to divide before
moving forward. At the G2 checkpoint, cellular DNA needs to be intact and undamaged before moving
forward. At the M checkpoint. The spindle fibers must be properly attached to the sister chromatids
before the cell moves forward.Cell cycle regulators provide feedback that contribute to the decision of
whether a cell proceeds past a checkpoint. The function of cell cycle checkpoints in the cell cycle
regulators is to ensure that a cell can successfully divide and to minimize errors introduced during
cellular division.
Snapdragon plans with a capital R, Capital R. Genotype. Have red flowers. And plants with.
Lowercase R, lowercase R. Genotype. Have white flowers. And plans with a. Capital R, lowercase
R. Have pink flowers. Explain why this illustrates an exception to the Mendel’s laws. And which of
Mendel’s laws? This isn’t an observation too. A red flowering plant and a white flowering plant.
Are crossbred. What are the genotypes and phenotypes discovered in the F1 generation? What are
the genotypes and phenotypes observed in the FQ generation?
This illustrates incomplete dominance, which is an exception to Mendels law of dominance. Even in well
is dominant over the other allele. The genotype would produce red flowers rather than intermediate
genotype with pink flowers. The F1 generation of a cross between a. RR. Plant and an rr. Plant. Would
have all. Rr. Genotypes with pink flowers. The F2 generation would be between the two RR and 2 rr, 25%
of the plants would be RR. And have red flowers. 50% of plants would be Rr, And 25% of the plants
would be rr and have white flowers.
Compare and contrast transcription and translation describe how these processes are related.
Transcription and translation are both steps in the gene expression. These processes are related because
they are sequential. Transcription happens first, and translation uses the M RNA product of the
transcription as input To create a polypeptide.
Once the function of DNA, name the three primary types of RNA. And list their functions.
DNA stores the genetic information for living organisms. Three types of RNA are mRNA, tRNA and
rRNA. mRNA is short for messenger RNA, and this is the transcription product that’s copied from a DNA
strand that is used as a template in the process of translation. tRNA, short for transfer RNA brings
specific amino acids to the growing polypeptide chain during translation. rRNA, short for ribosome
RNA, is part of the ribosome, which is the site of translation.
Describe why DNA replication is called semiconservative. Name two enzymes required for DNA
replication and explain their functions.
DNA replication is semiconservative because it uses each of the strands of a DNA double Helix as a
template, so that the two double helices produced after replication each have an old strand of DNA and a
newly synthesized strand of DNA. The enzyme helices unwinds a double strand of DNA and separates
the two strands to be used as templates. The enzyme Topa Amoris. Relaxes the DNA and controls the
supercoiling that occurs as the DNA double Helix is unwound.The enzyme primase is required to lay
down short stretches of RNA nucleotides that are complementary to the DNA template before DNA
, nucleotides can be added to the template. The enzyme DNA polymerase adds DNA nucleotides
complementary to the template strand to form a new strand of DNA. The enzyme laggies joins the
Okazaki fragments together to create a continuous DNA strand.
Assume that two genes follow a simple dominant recessive pattern of inheritance. With one located
on the autosomal chromosome and one located on the X chromosome. Two parents are
heterozygous for the autosomal gene KK. The father has a dominant L on the X chromosome X,
while the mother is heterozygous **. Which percentage of their children will exhibit the recessive
phenotypes? How is this different between the male and female offspring? What percentage of
offspring will be carriers for the recessive L of the X linked gene?
The autosomal gene will follow the classic mandolin inheritance with 25% of the children homozygous
dominant KK, 50% of the children heterozygous KK, and 25% of the children homozygous recessive
KK. For assessing, phenotype will be seen in 25% of the offspring with no difference between male and
female. Allele gene is different between males and females. Males do not receive excellent genes from
their fathers. So 50% of the male offspring will have the recessive phenotype with the X genotype and
50% of male offspring will have the dominant phenotype with the X genotype. Females do receive
excellent genes from their father. No female offspring will have the recessive X linked phenotype. 50% of
female offspring will be homozygous dominant for the X linked Gene ** and 50% of the female offspring
will have the dominant phenotype but the carriers that are recessive LL of the xling gene with The **
genotype.
Explain how usner, Lamarque, and Hutton and Lyle viewed the evolution of species, or how their
views influenced Charles Darwin.
Usher was an Irish Bishop who interpreted the Bible literally and advocated for creationism. He believed
that Earth was less than 6,000 years old. Usher’s views were popular during Darwin’s time. Making
Darwin’s deals on evolution controversial. Lamarck. Was an advocate of Transformationalism, and more
specifically the inheritance of acquired characteristics.This viewpoint stated that the organisms adapted to
their environments and acquired traits that can be inherited by future generations. While the mechanisms
of inheritance were incorrect. Lamarck was among the first scientists to publicly state a mechanism for
how organisms might evolve. Hutton and Lyle were geologists who advocated for the idealism of
uniformitarianism. They argue that the laws of physics and chemistry are constant, so the same laws that
govern geological events in the past continue to shape the earth today. Darwin applied this idea to
biology, recognizing that the changes in the past are analogous to those continuing today.
Outline the conditions required for the Hardy Weinberg principle to apply to a population. If these
conditions are met, how can this principle be used?
The Hardy Weinberg principle applies to the populations that are at equilibrium and aren’t evolving. The
Hardy Weinberg principle states that a low frequency of a population are stable if there are no genetic
mutations. The population is large and is unaffected by genetic drift. The population is isolated without
gene flow, mating is random and the natural selection is not occurring these conditions. Art often met. If
these conditions are met, the Hardy Weinberg property principle can be used to calculate allele
frequencies.
