Biology 150 Fall 2025 Unit 1 Learning Objectives

These flashcards cover key vocabulary terms and definitions relevant to the learning objectives outlined in the Biology 150 Fall 2025 course material.

Scientific Method

A systematic procedure scientists use to investigate questions and test hypotheses.

Hypothesis

A proposed explanation for a phenomenon, which can be tested through experimentation.

Theory

A well-substantiated explanation of an aspect of the natural world that is based on a body of evidence.

Causation

Establishing that one event is the result of the occurrence of another event.

Correlation

A statistical measure that describes the extent to which two variables are related.

Null Hypothesis

A statement asserting that there is no significant effect or relationship between the variables.

Dependent Variable

The variable that is measured and affected in an experiment.

Independent Variable

The variable that is manipulated or changed in an experiment.

Control Group

The group in an experiment that does not receive treatment, serving as a benchmark.

Experimental Study

Research that tests a hypothesis by manipulating variables and observing effects.

Observational Study

Research that relies on observing variables without manipulating them.

Continuous Data

Data that can take any value within a range; often represented in graphs like line graphs.

Categorical Data

Data that can be divided into distinct categories; often represented in graphs like bar charts.

Line Graph

A type of graph that uses points connected by lines to show changes over time.

Scatterplot

A graph that displays values for two variables for a set of data.

Bar Graph

A graphical representation of data using bars of different heights or lengths.

Box and Whisker Graph

A graphic that displays data distributions through their quartiles.

Pie Chart

A circular chart divided into sectors, illustrating numerical proportions.

Nucleotide

The basic building block of DNA and RNA, composed of a sugar, phosphate group, and nitrogenous base.

Complementary Base Pairing

The pairing of nitrogenous bases in DNA and RNA according to specific rules (A with T, C with G).

Directionality of DNA

Refers to the orientation of the DNA strand, indicating the 5' to 3' directionality.

RNA

Ribonucleic acid, a molecule that plays a central role in the coding, decoding, regulation, and expression of genes.

Double Helix

The spiral shape of DNA formed by two strands of nucleotides.

Replication

The process of duplicating DNA before cell division.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process where the RNA is decoded to produce proteins.

Genotype

The genetic constitution of an organism, represented by alleles.

Phenotype

The observable characteristics or traits of an organism, related to its genotype.

Allele

An alternative form of a gene that can exist at a specific locus.

Ploidy

The number of sets of chromosomes in a cell.

Diploid

A cell with two complete sets of chromosomes, one from each parent.

Haploid

A cell containing a single set of chromosomes.

Homologous Chromosomes

Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Sister Chromatids

Identical copies of a chromosome, joined together by a centromere.

Point Mutation

A change in a single nucleotide base in a DNA sequence.

Silent Mutation

A mutation that does not alter the protein produced.

Missense Mutation

A mutation that results in a different amino acid being incorporated into a protein.

Nonsense Mutation

A mutation that creates a premature stop codon in the protein sequence.

Frameshift Mutation

A mutation that shifts the reading frame of the genetic message.

Meiosis

A type of cell division that reduces the chromosome number by half, producing gametes.

Gamete

A reproductive cell, such as sperm or egg, that carries half the genetic information.

Dominant Allele

An allele that expresses its phenotype even in the presence of a recessive allele.

Recessive Allele

An allele that expresses its phenotype only when two copies are present.

Punnett Square

A diagram used to predict the genotypes of offspring from genetic crosses.

Independent Assortment

The principle that alleles of different genes assort independently of one another during gamete formation.

Gene Linkage

The tendency of genes located close together on a chromosome to be inherited together.

Hardy-Weinberg Equilibrium

A principle that describes a non-evolving population where allele and genotype frequencies remain constant.

Gene Pool

The complete set of genetic information within a population.

Allele Frequency

The relative frequency of an allele at a genetic locus in a population.

Genotype Frequency

The proportion of a specific genotype within a population.

Phenotype Frequency

The ratio of individuals expressing a particular phenotype compared to the total population.