Show:
A. Unity and Diversity
B. Form and Function
C. Interaction and Interdependence
D. Continuity and Change
Nature of Science
100

Describe one physical property of water that makes it essential for life.

Water has a high thermal conductivity, which allows it to absorb and transfer heat. This is important for regulating the temperature of living organisms.

100

Describe the role of carbohydrates in providing energy for living organisms.

Carbohydrates are a major source of energy for many organisms. 

Monosaccharides like glucose can be broken down through cellular respiration to release energy in the form of ATP.

100

Describe the role of enzymes in the regulation of metabolic processes.

At least 1

Enzymes are biological catalysts that speed up the rates of chemical reactions in living organisms. 

By lowering the activation energy required for reactions, enzymes allow metabolic processes to occur at physiologically relevant rates.

Feedback inhibition helps regulate metabolic processes that produce or break down substances

100

Describe the semi-conservative nature of DNA replication.

At least 2 of thesE: 

The key points about the semi-conservative nature of DNA replication are:

  • Both original DNA strands are used as templates to guide the synthesis of new strands.
  • The new strands are formed by adding nucleotides one by one, with each new nucleotide being complementary to the corresponding nucleotide on the template strand.
  • When replication is complete, there are two DNA molecules, each composed of one original strand and one newly synthesized strand.
100

What are the 11 key aspects of the nature of science as described in the textbook?

At least 4 of the following

  1. Observations and experiments
  2. Measurements
  3. Evidence
  4. Patterns and trends
  5. Hypotheses
  6. Falsification
  7. Models
  8. Uncertainty
  9. Creativity
  10. Collaboration
  11. Ethical considerations
200

Outline the role of hydrogen bonding in the structure and function of DNA.

The double helix structure of DNA is stabilized by hydrogen bonding between the complementary base pairs (A-T and C-G). 

This hydrogen bonding allows genetic information to be replicated and expressed accurately.

200

Outline the structure and function of phospholipids in cell membranes.

2 of the following: 

Phospholipids are the main structural component of cell membranes. The phospholipid molecule has a hydrophilic head and two hydrophobic fatty acid tails. 

Phospholipids have an amphipathic structure allows phospholipids to self-assemble into a bilayer

Amphipathic structure allows for selectively permeable barrier of the cell membrane.

200

Outline the key steps involved in the light-dependent reactions of photosynthesis.

At least 3 in correct order:

The light-dependent reactions of photosynthesis occur in the thylakoid membranes of chloroplasts. 

These steps include:

light absorption by chlorophyll

the light-induced splitting of water

the transfer of electrons through the electron transport chain

the generation of ATP and NADPH using the proton gradient.

200

Outline the key steps involved in the process of protein synthesis.

At least 3 of the following in correct order

Protein synthesis occurs in two main stages - transcription and translation. 

Transcription involves the synthesis of messenger RNA (mRNA) from a DNA template

Using RNA Polymerase

Translation uses the mRNA as a template to direct the synthesis of a polypeptide chain at the ribosome

Using the Ribosome

Codons are converted into amino acids with the help of t-RNA's anticodons and their associated amino acids that are added to the chain

The polypeptide chain stops being produced when a stop codon is reached

200

What is the type of reasoning that involves going from specific observations to develop a general theory?

Inductive Reasoning

Biologists noticed a trend or pattern in their observations of cells, which led them to develop the cell theory through inductive reasoning (going from specific observations to a general theory).

300

Explain how the principle of complementary base pairing contributes to the replication of genetic information in DNA.

The complementary base pairing between adenine and thymine, and cytosine and guanine, allows the double helix structure of DNA to be replicated accurately. 

This base pairing ensures that the genetic information is accurately copied during DNA replication.

300

Explain how the structure of proteins relates to their function in biological systems.

2 of the following

The unique three-dimensional structure of proteins is determined by the sequence and interactions of their constituent amino acids (or named examples of bonds). 

The primary structure of proteins, or arrangement of 21 amino acids, allows for essentially limitless combinations for limitless functions.

This structure is crucial for the diverse functions of proteins, such as catalysis, transport, structural support, and cell signaling.


300

Explain how the structure of the electron transport chain in mitochondria is adapted to its function in cellular respiration.

2 of following: 

The inner mitochondrial membrane contains the enzymes and cofactors of the electron transport chain. 

The highly folded cristae structure of this membrane provides a large surface area 

High SA accommodates the protein complexes involved in the transfer of electrons and the pumping of protons to generate 

The proton gradient used for ATP synthesis.

300

Explain how mutations can alter the structure and function of proteins.

Any 2 of the following

Mutations are changes in the DNA sequence that can lead to alterations in the amino acid sequence of the resulting protein. 

Examples of mutations and their corresponding effects: 

--> Insertion/Deletion = Frameshift (potential disruption to entire protein structure after that point or lead to nonsense mutation)

Substitution mutations, where one nucleotide is replaced by another, can change single codon and lead to a different amino acid being incorporated into the protein, altering structure

Nonsense mutations, where a codon is changed to a stop codon, result in a truncated, non-functional protein.

300

Explain how the concept of falsification is important to the nature of science, using an example from the textbook.

The concept of falsification is important to the nature of science because hypotheses can be proved false using other evidence, even though they can't be definitively proved true. This has led to paradigm shifts in science throughout history as new evidence emerges to challenge existing theories.


Even though some structures in living organisms do not consist of typical cells, the cell theory has not been completely disproven. Rather, the ability to falsify the theory through new observations has allowed it to be refined and improved over time. This process of challenging existing theories with new evidence is a key aspect of the nature of science.

The textbook emphasizes that while hypotheses cannot be definitively proven true, they can be shown to be false. This openness to falsification is what drives the evolution of scientific understanding and leads to paradigm shifts when new evidence contradicts prevailing theories.

400

Discuss the role of viruses in the evolution of life on Earth.

One of the following: 

Viruses may have played a role in the early evolution of life by transferring genetic material between primitive cells, contributing to the diversification of life. 

The constant evolutionary arms race between viruses and their hosts has likely driven the evolution of more complex cellular defense mechanisms.

400

Discuss the role of organelles in compartmentalizing cellular processes.

2 of the following:

The presence of membrane-bound organelles in eukaryotic cells allows for the spatial separation and specialized functions of different cellular processes. 

For example, the mitochondria are responsible for cellular respiration, the endoplasmic reticulum is involved in protein synthesis and modification, and the nucleus contains the genetic material. 

This compartmentalization increases the efficiency and regulation of these essential cellular activities.

400

Discuss the role of chemical signaling in the coordination of physiological processes in multicellular organisms.

Allow 2 of the following

Chemical signaling molecules, such as hormones allow for slower, longer term, more widespread effects in the body

And neurotransmitters, allow for faster, more targeted effects from transmission along synapses

For Example: 

hormones can coordinate responses to environmental stimuli such as daylight vs no light (night)

neurotransmitters facilitate rapid signaling between neurons for the control of body functions (muscle movement, reflexes)

400

Discuss the role of cell division in growth, repair, and reproduction.

At least one from each:

Growth:

  • Mitotic cell division allows for the increase in the number of cells, enabling the growth and development of an organism from a single zygote.
  • Rapidly dividing cells in tissues like the epidermis and bone marrow facilitate the growth and replacement of worn-out or damaged cells.

Repair:

  • Mitosis enables the replacement of damaged or dead cells, allowing for the repair and regeneration of tissues.
  • Stem cells, which can divide indefinitely, play a crucial role in replenishing specialized cells lost due to injury or disease.

Reproduction:

  • Meiotic cell division is essential for sexual reproduction, generating haploid gametes (sperm and eggs) that can fuse to form a diploid zygote.
  • The genetic recombination that occurs during meiosis increases the genetic diversity of offspring, which is important for adaptation and evolution.
400

Discuss how the use of models in science relates to the nature of science, drawing on examples from the textbook.

The use of models in science relates to the nature of science because scientists construct models as simplified explanations of their observations. While models often contain assumptions or unrealistic simplifications, the aim of science is to increase the complexity of the model and reduce its limitations over time.

500

Evaluate the importance of cladistic analysis in the classification of organisms.

Must have at least one of each strength and limitation: 


Strengths:

  • Water has a high specific heat capacity, meaning it requires a large amount of energy to raise its temperature. This provides thermal stability in aquatic environments, allowing organisms to maintain relatively constant body temperatures.
  • The high latent heat of vaporization of water helps regulate the temperature of aquatic environments, as energy is absorbed during evaporation, preventing rapid temperature changes.
  • The high thermal conductivity of water allows it to efficiently absorb and transfer heat, which is crucial for regulating the body temperatures of aquatic ectotherms.

Limitations:

  • The high specific heat capacity of water also means it takes a lot of energy to heat up, which can be a challenge for aquatic organisms that need to maintain their metabolic rates.
  • The high latent heat of vaporization requires a significant amount of energy input to cause phase changes, which can limit the ability of aquatic organisms to use evaporative cooling as an effective thermoregulatory mechanism.
  • The insulating properties of water can trap heat, potentially leading to thermal stress for organisms in stagnant or shallow aquatic environments during periods of high solar radiation.
500

Evaluate the adaptations of mitochondria and chloroplasts that allow them to carry out their specialized functions.

For Mitochondria and Chloroplast must have1 Strength, 1 Limitation:

Mitochondria and chloroplasts exhibit several structural adaptations that enable them to perform their essential roles in cellular respiration and photosynthesis, respectively.

Adaptations of Mitochondria: Strengths:

  • The outer membrane separates the contents of the mitochondrion from the rest of the cell, allowing for an optimal internal environment for ATP production.
  • The highly folded inner membrane provides a large surface area for the electron transport chain and ATP synthase enzymes involved in oxidative phosphorylation.
  • The matrix compartment contains the enzymes and substrates required for the citric acid cycle and other metabolic pathways that generate NADH and FADH2 for the electron transport chain.

Limitations:

  • Mitochondria require a constant supply of oxygen and organic molecules to sustain aerobic respiration, which can be limited in certain environments.
  • The double membrane structure requires significant energy investment for the maintenance of electrochemical gradients across the inner membrane.
  • Damage or dysfunction of mitochondria can disrupt cellular energy production, leading to various metabolic disorders.

Adaptations of Chloroplasts: Strengths:

  • The double membrane structure isolates the chloroplast contents and provides a controlled environment for photosynthesis.
  • The internal thylakoid membrane system contains the chlorophyll and other pigments necessary for light absorption and the light-dependent reactions of photosynthesis.
  • The stroma compartment contains the enzymes and substrates required for the Calvin cycle and other biosynthetic pathways.

Limitations:

  • Chloroplasts are dependent on the availability of light energy, which can be limiting in certain habitats or during periods of low light.
  • The complex photosynthetic machinery requires a significant investment of resources and energy to maintain and replicate.
  • Chloroplasts are vulnerable to damage from excessive light exposure or environmental stresses that can disrupt photosynthesis.
500

Evaluate the importance of enzyme regulation in maintaining metabolic homeostasis.

At least 3 of the following (must have one stength, one limitation)

Cells have hundreds of different enzymes that catalyze a wide range of metabolic reactions. 

Enzymes can be regulated through allosteric sites and non-competitive inhibition

Describes how competitive inhibition can also modulate enzyme activity.

Strengths of enzyme regulation:

  • Allows cells to control the rates of specific metabolic pathways by increasing or decreasing enzyme activity
  • Feedback inhibition prevents the buildup of end products, maintaining metabolic homeostasis
  • Enzyme regulation enables rapid responses to changes in environmental conditions or cellular needs
  • Compartmentalization of enzymes within organelles further enhances metabolic control

Limitations of enzyme regulation:

  • Complex regulatory mechanisms require significant energy investment and can be vulnerable to disruption
  • Enzyme dysfunction or dysregulation can lead to metabolic disorders and disease states
  • Regulatory pathways may become overwhelmed in extreme conditions, leading to loss of metabolic control
500

Discuss the importance of genetic, ecosystem, and species diversity in maintaining the stability and resilience of natural systems in the face of climate change.

Genetic Diversity:

  • Genetic variation within a population provides the raw material for natural selection to act upon, enabling organisms to evolve adaptations to new environmental conditions.
  • Diverse genotypes can confer different physiological, behavioral, or life history traits that allow some individuals to better cope with the impacts of climate change, such as increased temperatures or altered precipitation patterns.
  • Maintaining high levels of genetic diversity increases the chances that a population will contain individuals with the necessary adaptations to survive and reproduce under the altered environmental conditions.

Ecosystem Diversity:

  • Ecosystems with a greater diversity of species and functional groups are more likely to withstand and recover from the disruptions caused by climate change.
  • Redundancy in ecosystem functions, provided by multiple species performing similar roles, can help maintain essential processes like nutrient cycling, primary production, and decomposition even if some species are lost.
  • The heterogeneity of diverse ecosystems can create a variety of microhabitats, allowing some species to find refuge from the direct impacts of climate change.

Species Diversity:

  • A higher diversity of species within an ecosystem increases the range of adaptations and responses available to cope with environmental changes.
  • Diverse communities are more likely to contain species that are pre-adapted to the new conditions brought about by climate change, facilitating the maintenance of ecosystem structure and function.
  • The presence of species with different life histories, dispersal abilities, and environmental tolerances can promote the reorganization and reassembly of communities in the face of climate-driven disturbances.
500

Analyze how the nature of science has evolved over time, as demonstrated by a historical example from the textbook.

a historical example of how the nature of science has evolved over time - the development of the cell theory. Initially, biologists could only observe plant cells using early microscopes, but as technology improved, they were able to examine animal tissues as well. This led them to the general conclusion that all organisms are made of cells, even though some exceptions have since been discovered.