Bio midterm

What is a model in scientific terms?

A representation of phenomena used to describe and explain processes, such as photosynthesis or DNA structure.

What characterizes useful scientific evidence?

Empirical, reproducible, and supports or refutes hypotheses based on observations and experiments.

What are the steps of the scientific method?

Observation → Hypothesis → Experiment → Data Collection → Conclusion.

What is an independent variable?

The factor that is changed by the researcher in an experiment.

What is a dependent variable?

The measured response that is affected by the independent variable.

What is the function of enzymes?

Biological catalysts that speed up chemical reactions within cells.

What is the difference between saturated and unsaturated fatty acids?

Saturated fatty acids have no double bonds and are solid at room temperature, while unsaturated fatty acids have at least one double bond and are typically liquid.

What are the three components of nucleotides?

Phosphate group, five-carbon sugar, and nitrogenous base.

What is dehydration synthesis?

A reaction in which smaller molecules join together to make a larger molecule, releasing water as a by-product.

What does the pH scale measure?

The acidity or alkalinity of a solution.

Define homeostasis.

The maintenance of optimal internal conditions within an organism.

What is a prokaryotic cell?

A smaller cell type with no nucleus and circular DNA, where functions occur in the cytoplasm.

What is a eukaryotic cell?

A larger cell type with a nucleus and membrane-bound organelles.

What are the characteristics of living things?

Organization, growth and development, energy use, response to stimuli, homeostasis, reproduction, evolution.

What is the role of the chloroplasts?

To capture energy from sunlight and convert it into chemical energy.

How do scientists share findings?

Through peer-reviewed journals, conferences, and collaborations.

What is the definition of a biogeochemical cycle?

The cycling of matter among living and nonliving components of ecosystems.

What is the role of ribosomes?

The site of protein synthesis in the cell.

What is competitive exclusion principle?

No two species can occupy the same niche in the same habitat at the same time.

Describe the nitrogen cycle.

Nitrogen is fixed by bacteria, converted into usable forms for plants, and recycled through decomposition and denitrification.

What defines a climax community?

A stable, uniform community thought to be the 'end' of succession, though this is not always true.

What is the role of decomposers in an ecosystem?

To break down dead organisms and return nutrients to the soil.

What is a population density?

The number of individuals of a species per unit area.

What are limiting factors?

Factors that control the growth of a population.

What is synthesis in biological terms?

The process of creating larger molecules from smaller units, such as constructing proteins from amino acids.