PART I.
MULTIPLE CHOICE QUESTIONS [8 points]
Identify the correct answer.
Where does Earth's water come from?
1. Volcanic activity
2. Meteorites
3. Primordial soup
4. All of the above
Because water vapor and other volatile compounds were released from
the interior of the planet during volcanic eruptions.
Who was the first scientist to "cook" the primordial soup?
1. Charles Darwin
2. Stanley Miller
3. Alfred Russel Wallace
4. Louis Pasteur
In 1953, he conducted the Miller-Urey experiment, simulating early
Earth's conditions by creating a mixture of gases and subjecting it to
electric sparks.
What is the approximate age of Earth?
1. 3 million years
2. 5 billion years
3. 10,000 years
4. 1 billion years
The approximate age of Earth is indeed around 4.5 billion years.
What ion did the first life obtain from the sea vents?
1. Oxygen
2. Iron
3. Hydrogen
4. Sulphide
It is likely that the first living things obtained hydrogen ions from
hydrothermal vents. These sources release hot, mineral-rich fluids into
the ocean, creating a chemical gradient. Hydrogen helped early life
forms to survive and other things.
What is the role of ribozymes in early life?
1. Energy production
2. DNA replication
3. Protein synthesis
4. RNA cleavage and splicing
This allowed for RNA processing, including the removal of unnecessary
segments and the joining of functional RNA sequences, crucial for RNA
replication and the transmission of genetic information.
What is the primary form of genetic variation among humans?
1. Single-Nucleotide Polymorphisms (SNPs)
2. Insertions
3. Deletions
4. Translocations
They are variations in individual nucleotide base pairs within DNA
sequences and are widespread throughout the genome, influencing
traits such as appearance and susceptibility to disease.
Define sympatric speciation.
1. Speciation due to geographic barriers
2. Speciation occurring in the same location.
3. Formation of new species through hybridization
4. Evolution driven by ecological factors.
Sympatric speciation is when new species evolve from a single
ancestral species in the same habitat.
What does the term "Omnis cellula e cellula" mean?
1. Cells are the basic unit of life.
2. All cells arise from pre-existing cells.
3. Cells have a common ancestry
4. Cells are diverse in structure
This principle, proposed by Rudolf Virchow, emphasizes that new cells
are formed through cell division from existing cells, a fundamental
concept in biology known as the cell theory.
PART II. ESSAY QUESTIONS. [7 points]
9. Give one example of a species evolving into different forms.
An evolution that has different results is the monkey, which is said to give rise to
the homo sapiens, that is, the human being, and the same monkey but smaller
because the animals before were much larger.
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10. Explain how the Congo River affect chimps and bonobos evolution.
The Congo River affect chimpanzees and bonobos by acting as a barrier to gene
flow, driving divergent selection, and influencing genetic diversity within each
species.
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11. Name the two types of mechanisms preventing species from mating or
having viable offspring.
• ecological isolation
• geographic isolation.
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12. Name a contribution of Anton van Leeuwenhoek and Robert Hooke
to the early understanding of cells.
• Anton van Leeuwenhoek: First observation of single-celled
organisms.
• Robert Hooke: In his work "Micrographia", published in 1665,
Hooke provided illustrations and detailed descriptions of a
wide range of microscopic structures, including cells.
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13. Explain the role of ribosomes in prokaryotic cells.
Ribosomes help amino acids assemble to form proteins.
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14. Explain how the Human Genome Project contributes to our
understanding of genetic disorders.
The Human Genome Project is like a very large map of all the little parts that
make people unique. It's like an instruction book that contains all the things that
make us who we are, like the color of our eyes, the shape of our nose, and much
more. And it makes us humans understand each other better.
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15. Define the ecological species concept and provide an example.
This concept emphasizes the importance of understanding how species adapt to
their environment and use resources. An example may be the case of Darwin's
finches in the Galapagos Islands. These finches with a common ancestor have
adapted to different locations and each with a different beak.
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PART III. DATA-BASED QUESTIONS. [10 points]
Read the information and identify the missing organelles. (2 points each)
E
16. _ _Nucleus: The nucleus is the membrane-bound organelle that houses the
genetic material in the form of chromatin, comprising DNA and associated
proteins. As the central control center of the cell, the nucleus orchestrates
cellular activities by regulating gene expression, DNA replication, and RNA
synthesis, thereby governing growth, development, and maintenance of cellular
functions.
A
17. _ _Cell Membrane (Plasma Membrane): The cell membrane is a selectively
permeable phospholipid bilayer that encases the cell, serving as a dynamic
barrier that regulates the passage of ions, molecules, and signaling substances. It
facilitates cellular communication and maintains homeostasis by controlling the
exchange of materials between the internal and external environments.
D
18. _ _Endoplasmic Reticulum (ER): The endoplasmic reticulum is a complex
network of membranous structures involved in the synthesis, folding,
modification, and transport of proteins and lipids. The rough endoplasmic
reticulum (RER), studded with ribosomes, specializes in protein synthesis and
initial folding, while the smooth endoplasmic reticulum (SER) participates in lipid
metabolism, detoxification reactions, and calcium ion storage, collectively
contributing to cellular homeostasis and the maintenance of cellular structure.
19. _C_ Mitochondria: Mitochondria are double-membraned organelles
responsible for energy production through oxidative phosphorylation. Serving as
the powerhouse of the cell, mitochondria generate adenosine triphosphate (ATP)
by metabolizing nutrients through the citric acid cycle and the electron transport
chain. Additionally, mitochondria play a pivotal role in cellular signaling,
apoptosis, and contribute to cellular redox balance.
B
20._ _Cytoplasm: Cytoplasm is the semifluid matrix within the cell, composed
of water, ions, organic molecules, and various cellular structures. Acting as the
medium for biochemical reactions, the cytoplasm supports the movement and
interaction of organelles, facilitating essential cellular processes such as
metabolism, transport, and structural integrity.
