Biology Semester 2 Exam Vocabulary Practice

A comprehensive collection of vocabulary terms covering cell biology, energy, genetics, and evolutionary science based on the Semester 2 Exam Study Guide.

Compound/Light Microscope

A tool used to view small specimens using visible light and multiple lenses to magnify the image.

Eukaryotes

Cells that contain a nucleus and membrane-bound organelles.

Prokaryotes

Cells that lack a nucleus and membrane-bound organelles.

Plasma Membrane

A cell boundary composed of various components that regulates membrane transport and maintains cellular integrity.

Hypertonic

A solution state where there is a higher concentration of solute compared to the inside of a cell, causing water to exit the cell.

Hypotonic

A solution state where there is a lower concentration of solute compared to the inside of a cell, causing water to enter the cell.

Isotonic

A solution state where the concentration of solute is equal to the concentration inside the cell, resulting in no net water movement.

Autotroph

An organism that can produce its own food and energy from inorganic substances.

Heterotroph

An organism that must consume other organisms to obtain energy.

ATP (Adenosine Triphosphate)

The primary energy carrier molecule in cells; it releases energy when a phosphate bond is broken.

Photosynthesis Equation

$$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$$

Chlorophyll

The primary pigment found in the chloroplasts of plants and other photosynthetic organisms.

Calvin Cycle (Light-Independent Stage)

The second stage of photosynthesis that occurs in the stroma; it uses ATP and NADPH to convert $CO_2$ into glucose.

Aerobic

Processes or organisms that require oxygen to produce energy.

Anaerobic

Processes or organisms that do not require oxygen to produce energy.

Cellular Respiration Equation

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$$

Lactic Acid Fermentation

A type of anaerobic respiration occurring in animal muscle cells and some bacteria that produces lactic acid as a main product.

Alcoholic Fermentation

A type of anaerobic respiration occurring in yeast and some bacteria that produces ethanol and $CO_2$.

Cell Division

The process by which a parent cell divides into two or more daughter cells.

Mitosis

A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typically for growth and tissue repair.

Meiosis

A specialized type of cell division that reduces the chromosome number by half, creating four genetically distinct haploid gametes.

Interphase

The stage of the cell cycle where the cell grows ($G_1$), replicates its DNA ($S$), and prepares for division ($G_2$).

Chromosome

A threadlike structure of nucleic acids and protein found in the nucleus, carrying genetic information in the form of genes.

Chromatin

The material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed; the unorganized state of DNA when a cell is not dividing.

Cytokinesis

The division of the cytoplasm at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

Cancer

A disease caused by an uncontrolled division of abnormal cells in a part of the body.

Mutagen

A physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations.

mRNA (messenger RNA)

A single-stranded molecule of RNA that is complementary to one of the DNA strands of a gene and carries genetic information to the ribosome.

Transcription

The first stage of protein synthesis where a segment of DNA is copied into mRNA in the nucleus.

Translation

The second stage of protein synthesis where mRNA is decoded by a ribosome to produce a specific amino acid chain, or polypeptide.

Mutation

A change in the nucleotide sequence of the genome of an organism.

Crossing Over

The exchange of genetic material between homologous chromosomes during prophase I of meiosis, resulting in genetic variation.

Genetics

The branch of biology that deals with the study of heredity and the variation of inherited characteristics.

Gregor Mendel

The Austro-German scientist and Augustinian friar who is considered the "Father of Genetics."

Homozygous

An individual having two identical alleles of a particular gene (e.g., $AA$ or $aa$).

Heterozygous

An individual having two different alleles of a particular gene (e.g., $Aa$).

Phenotype

The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Genotype

The genetic constitution of an individual organism.

Allele

One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Sex-linked Trait

A trait that is controlled by a gene or an allele located on the sex chromosomes.

Autosomes

Any chromosome that is not a sex chromosome.

Adaptation

A change or the process of change by which an organism or species becomes better suited to its environment.

Natural Selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring; often described as "survival of the fittest."

Artificial Selection

The identification by humans of desirable traits in plants and animals and the steps taken to enhance and perpetuate those traits in future generations.