Nature of Science and Cell Cycle Regulation

Flashcards defining core vocabulary terms from lecture notes on the nature of science, scientific method, eukaryotic cell cycle stages, cell cycle regulation proteins, and cancer development.

Biology

The study of life, derived from "bio" meaning life and "ology" meaning the study of.

Scientific Process

A method for describing and explaining the natural world that uses evidence to construct testable explanations and predictions of natural phenomena.

Science

A method for explaining the natural world using evidence to construct testable predictions, as well as the body of knowledge generated through this process.

Amoral

Neither moral nor immoral; characteristic of science because moral, ethical, and spiritual questions lie outside its domain.

Hypothesis

A tentative statement about the natural world leading to predictions that can be tested.

Independent Variable

The variable in an experiment that is systematically manipulated (the hypothesized cause) and plotted on the x-axis of a graph.

Dependent Variable

The outcome variable in an experiment that is measured (the effect) and plotted on the y-axis of a graph.

Controls

Variables in an experiment that a researcher attempts to keep constant to isolate the effect of the independent variable.

Scatter Plot

A type of graph used to display data when both the independent and dependent variables are continuous.

Bar Plot

A type of graph used when the predictor variable is categorical and the outcome variable is continuous.

Observation

The act of perceiving and recording data/facts about a natural phenomenon using the senses or scientific instruments.

Inference

A conclusion or interpretation drawn based on observed facts and data.

G1 Phase

The first growth phase of the eukaryotic cell cycle in which cell growth occurs prior to DNA synthesis.

S Phase

The synthesis phase of the cell cycle during which DNA replication occurs.

G2 Phase

The second growth phase of the cell cycle following DNA replication where further cell growth occurs prior to mitosis.

M Phase

The mitotic phase of the cell cycle during which nuclear division (mitosis) and cellular division (cytokinesis) take place to produce two daughter cells.

G0 Phase

A quiescent (dormant) state outside the active cell cycle where a cell undergoes no further growth or division.

Cell Cycle Checkpoint

Control mechanisms in the eukaryotic cell cycle (including G1 restriction, G2, and M checkpoints) that regulate cell cycle progression and ensure proper conditions before division.

p53 Protein

A cellular tumor suppressor protein that detects DNA damage and activates genes for p21, DNA repair mechanisms, or initiates apoptosis.

p21 Protein

A regulatory protein activated by p53 that halts the cell cycle by inhibiting Cdk/cyclin complexes.

Apoptosis

Programmed cell death that can be triggered when irreparable DNA or cellular damage occurs.

Rb Protein

A tumor suppressor protein that monitors cell size and inhibits DNA replication genes by binding to the transcription factor E2F.

E2F

A transcription factor that promotes the expression of genes needed for DNA replication, which is held in check by binding to the Rb protein.

Human Papillomavirus (HPV)

A common virus that infects host cells, causes abnormal cell reproduction, and disrupts cell cycle checkpoints through viral proteins E6 and E7.

E6 Protein

A viral protein produced by HPV that inhibits the function of the cellular p53 protein.

E7 Protein

A viral protein produced by HPV that inhibits the function of the cellular Rb protein.

Cancer

A state of uncontrolled cell growth often caused by mutations or viral proteins that disrupt normal cell cycle checkpoint mechanisms.