Question

Explain the scientific method and how it’s used to reveal an accurate understanding of living things; distinguish information resulting from scientific inquiry from that based on anecdotes and deceptive, non-scientific studies. Describe the chemistry of living things and relate biochemicals and their reactions to energy transformations between organisms and their environments; explain the conversion of light energy to chemical energy resulting in the connection between producers and consumers. Describe the variation of cell structures among organisms and contrast them with non-living particles such as viruses; explain how cell anatomy and function impacts the organism as a whole. Explain the various ways that cells reproduce and how they relate to DNA replication and inheritance; relate molecular, chromosomal, and cellular activities to genetic variation and evolutionary change. Explain the process of gene expression and regulation and how gene products result in the characteristics of organisms; describe how these genetic processes contribute to adaptive change from generation to generation. Understand commonly used biotechnologies, recognize their practical applications and ability to reveal evolutionary relationships and change; recognize the responsibility associated with the correct use and interpretation of these technologies.

Answer 1

• 1. Generally certain characteristics are observed to characterize living things, which include:

1. Observation for growth:

• The dimensions of the sample are measured, in terms of length, width and height to decimal units.
• The mass of the sample is measured to decimals units.
• The sample is then incubated at different temperatures for different period.
• Final dimensions and mass are measured and compared with initial measurements.

2. Observation for reproduction:

• Microscopic, Cytometric or other cell count methods may be used to observe unit or cell count of the specimen.
• The initial measurement may be compared after incubation of cells over time.

3. Observation for use of energy.

• The sample may be subjected to light and dark period for a time range.
• Sample may also be grown on minimal or basal media, with varying nutrient sources, with varying ranges of pH and incubation over temperature range and time range.
• Observation are calculated in terms of growth.

4. Observation for response to stimulus:

• The physical properties like shape, color, surface characteristics like smooth, rough, protrusions etc. are observed.
• The specimen is subjected to stimuli: temperature range, pH range, light intensity, electric stimulus, sound variation, magnetic field, etc.
• Observation is made in term of:

1. Movement- whole body, part, or protrusion or cell surface movements.

2. Change in physical characteristics- color, shape, dimension alteration.

3. Change in bio-chemical or physiological properties of sample, like production of new chemicals, secretions, proteins etc.

• 2. The systemic approach to obtain knowledge about natural world is Science.

This is because of following aspects

• Science provides basic knowledge about understanding life.
• A lay man may also gain knowledge about scientific proceedings and making consent decision. But the knowledge should be appropriate, trustworthy and a source of reliable authority.
• The reliability of a scientific knowledge should have credentials, proper affiliations, peer reviewed, analyzed by critical thinking.
• Thus,Scientific theory is described as tentative propositions to provide explanation of natural world phenomenon, which are repeatedly confirmed through observation and experiment.
• Scientific methods are empirical methods, used with proper evidences to prove a theory.
• It includes rigorous and systematics procedures, to eliminate errors and discrepancies to obtain a result and reach to a conclusion

The steps include:

1. To consider an idea to conduct the experiment related to the aim.

Variables may be included during the experiment, which include:

• Independent variable: variable which is altered during experiment.
• Dependent variable: Variable whose effect is altered due to the variation in the independent variable.
• Controlled variable: Variable that is constant for the specific experiment.

2. Deduce a hypothesis based on observation, that is needed to be proven.

3. Theory relates to explanation of the data.

4. When the data prove the hypothesis, it becomes the law.

• 3. Energy transformation:

• In an ecosystem, energy flow initiates at the producer level.
• Phototrophs can capture light energy with help of photosynthetic pigments, including chlorophylls, bacteriochlorophylls and accessory pigments.
• During the process of photosynthesis, light energy is converted to chemical energy, which generates energy in form of the “assimilatory power”, or ATP.
• The energy then flows to the primary consumers, who feed directly on the producers, then to the secondary consumers feeding on primary consumer.
• The energy in the cell is liberated as heat during metabolic reaction, or decomposition of body.

• 4. light energy chemical energy:

During the process of photosynthesis, light energy is converted to chemical energy, which generates energy in form of the “assimilatory power”, or ATP.

Photosynthetic organisms and plants, have pigments, that can absorb a specific quantum (absorption spectra) of light energy or photons.

This absorption of light energy, to generate ATP from ADP and Pi, can be quantified using Planck’s equation.

Plank’s theory describes that, energy transfer of energy is in form of unit known as quantum. In case of light, the quantum is referred to as photon. The energy of each quantum, is directly proportional to the frequency of radiation.

Thus, Plank’s equation states:

λ (2.99792458 × 108 m

• 5. Variation in cell structure:

• 1. Bacteria:

• Prokaryotic characteristics (Pro= primitive, Karyon = nucleus)
• Nucleus lacks membrane and nucleolus, is present as nucleoid material.
• Unicellular, complex organelles absent.
• Cell wall is present made of peptidoglycan with muramic acid.
• Membrane lipids have ester, straight chain fatty acids.
• Methionine formylated.
• Asexual mode of reproduction
• Autotrophic- photosynthetic or chemosynthetic. Heterotrophic- chemo-litho or organotrophic.
• Photosynthetic pigments may be present in some species.
• Movement by flagella.

• 2. Archaea:

• Prokaryotic characteristics (Pro= primitive, Karyon = nucleus)
• Nucleus lacks membrane and nucleolus, is present as nucleoid material.
• Unicellular, complex organelles absent.
• Cell walls do not have muramic acids.
• Membrane lipids have ether, branched aliphatic chains.
• Methionine not formylated.
• Asexual mode of reproduction
• Extremophiles are present, methanogens, methanotrophs.
• Chemosynthesis, photosynthetic pigments not present.
• Heterotrophic absorption

• 3. Eukarya:

• Eukaryotic organisms (Eu=True, Karyon = nucleus).
• Unicellular or multicellular.
• Nucleus with membrane and nucleolus, chromosomes.
• Cell wall if present is mainly cellulosic.
• Complex membrane bound organelles present.
• Membrane lipids have ester, straight chain fatty acids.
• Methionine formylated.
• Photosynthesis with chlorophylls, also heterotrophic.
• Flagella is present, is 9+2 orientation.

Virus:

• Viruses are very small infectious particles, of about 20-400 nanometers in diameter. Viruses comprise of nucleic acid (DNA or RNA), enclosed within a proteinaceous coat or capsid.