Biology I Exam Study Guide

These flashcards cover key concepts from the Biology I exam study guide, facilitating easier review and understanding of important topics.

What is a hypothesis in scientific terms?

A reasonable explanation of an observation or experimental result that can be tested.

What is the difference between a theory and a scientific law?

A theory is an explanation supported by evidence but may change, while a law describes universal facts supported by irrefutable data.

What are the three parts of the ATP molecule?

Adenine, ribose, and three phosphate groups.

Define osmosis.

The diffusion of water molecules from an area of higher water concentration to lower water concentration.

What is the purpose of meiosis?

To create gametes with half the number of chromosomes for sexual reproduction.

What is the structure that contains DNA in eukaryotic cells?

Nucleus.

Differentiate between prokaryotic and eukaryotic cells.

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.

What is the function of enzymes?

To serve as catalysts that accelerate chemical reactions in organisms.

What are the four main principles of natural selection?

Overproduction of Offspring, Variation, Adaptation, and Descent with Modification.

What is homeostasis?

An organism's ability to maintain a stable internal environment.

Define the term 'biomass pyramid.'

A model that shows the total mass of living organic matter at each trophic level in an ecosystem.

What do Punnett squares illustrate?

The probabilities of offspring inheriting specific traits based on the genetics of the parents.

What is the primary source of energy for most ecosystems?

Sunlight.

What is a gene?

A segment of DNA that codes for a protein and is located at a specific place on a chromosome.

Explain the difference between dominant and recessive alleles.

Dominant alleles will be expressed in the phenotype if present, while recessive alleles will not be expressed unless two copies are present.

What is meant by 'selective permeability' in relation to cell membranes?

The ability of a cell membrane to control what substances can enter or exit the cell.

Describe the term 'speciation.'

The process through which new species arise from preexisting species, usually through isolation or adaptation.

What is the role of ribosomes in the cell?

To serve as the site of protein synthesis.

What is genetic drift?

A random change in allele frequency within a population that can lead to a loss of genetic diversity.

What is the significance of the Hardy-Weinberg principle?

It describes the conditions required for a population to remain in genetic equilibrium, meaning allele frequencies won't change.

What are the three types of symbiotic relationships?

Mutualism, Commensalism, and Parasitism.