Cell Biology Flashcards

Vocabulary flashcards about cell biology, covering topics such as mitosis, meiosis, cell cycle phases, and transport mechanisms.

Nucleus

Contains the majority of the cell’s genetic material and controls the function of the entire cell by regulating gene expression.

Gregor Mendel

Discovered the fundamental laws of inheritance, deducing that genes come in pairs and are inherited as distinct units, one from each parent.

Chromosome

Thread-like structures in which DNA is packed.

Gene

The hereditary unit consisting of a sequence of DNA, which gives instructions on how to express a hereditary character in an organism.

Centromere

The region joining two sister chromatids, dividing the chromosome into two sections called arms (p arm and q arm).

Chromatid

One-half of two identical copies of a replicated chromosome, formed from chromatin fibers.

Sister Chromatids (Dyads)

Joined chromatids that make up one arm.

Telomeres

Repetitive nucleotide sequences at the end of chromatids that protect the ends of chromosomes from damage and ensure equal partitioning of genetic materials during cell division.

Mitosis

Cell reproduction of somatic cells, resulting in daughter cells that are identical to parent cells.

Meiosis

Cell reproduction leading to the production of gametes (sex cells, reproductive cells, sperm and egg cells for humans).

Gap 0 phase (G0)

Resting phase of the cell where the cell stops dividing.

Interphase

Phase during which the cell grows and makes a copy of its DNA.

Prophase

Phase where chromosomes duplicate, the nuclear envelope shatters, and polar spindles form.

Metaphase

Phase where spindles are fully developed and chromosomes align at the center of the cell (metaphase plate).

Anaphase

Phase where sister chromatids separate and move to opposite poles of the cell.

Telophase

Phase where chromosomes are contained in the new nucleus of each forming daughter cell.

Cytokinesis

The division of the parent cell's cytoplasm into two daughter cells after telophase.

G1 Restriction Point

The point where the cell becomes committed to undergo cell division, ensuring it has the right size, nutrients, DNA integrity, and positive cues from neighbors.

G2 Checkpoint

Checkpoint that prevents cells from entering the mitotic phase if their chromosomes are found to contain defects, ensuring accurate replication.

M Checkpoint (Spindle Checkpoint)

Checkpoint that checks if all sister chromatids are attached to the spindle microtubules near the end of metaphase.

Cyclins

Proteins active in regulating the cell cycle.

Cyclin-dependent kinases (Cdks)

Enzymes activated by cyclin which modify some proteins in the cell so that cell division takes place as it should.

Meiosis

Division of a cell involving two fissions of a nucleus, resulting in four gametes (sex cells).

Chiasmata

Point where paired chromosomes remain in contact during prophase I and metaphase I of meiosis.

Crossing Over

Exchange of genes which increases genetic variability, beginning in prophase I of meiosis.

Recombination of DNA

Exchange of DNA molecules, happening between homologous chromosomes during prophase I of meiosis.

Aneuploidy

A gain or loss of chromosome from the normal count of 46 in humans.

Trisomy

The presence of an extra chromosome in cells.

Cloning

Also known as the biological process of creating an exact copy of a biological unit (DNA sequence, a cell, or an entire organism) from which it is derived through biotechnological methods.

Stem Cells

Undifferentiated cells that can be induced to develop into specialized cells and multiply through mitosis, found in embryonic and adult tissues.

Cell Membrane

Structure that envelops the entire cell and regulates substances that enter and leave the cell; selectively permeable to ions and organic molecules.

Passive Transport

Molecules move across cell membranes without the help of energy due to differences in chemical or electrical gradients.

Gradient

Imbalance in concentrations.

Chemical Gradient

Differences in concentrations of ions across a membrane.

Electrical Gradient

Differences in electrical charges of ions across a membrane.

Tonicity

Relative concentration of solutes in two fluids separated by a selectively permeable membrane.

Facilitated Diffusion

Diffusion facilitated by membrane transport channels.

Active Transport

Movement of molecules with the help of energy, against the flow of gradient.

Primary Active Transport

Uses ATP and ADP to move molecules across a membrane against the gradient.

Secondary Active Transport (Cotransport)

Uses the electrochemical gradient generated by primary active transport.

Bulk Transport

Movement of large quantities of materials in and out of the cell, requiring energy.

Endocytosis

A cell takes in particles from its external environment into the cell interior.

Phagocytosis

The cell surrounds the material with part of its membrane.

Pinocytosis

The cell engulfs drops of liquid, forms vesicles smaller than phagocytes, and brings them to the lysosome for digestion

Receptor-Mediated Endocytosis

The cell targets specific molecules that bind with protein receptors, located in coated pits, on the surface of a cell membrane.

Exocytosis

A cell exports materials out of the cell through secretory vesicles.

Hydrolytic enzyme

Enzymes that allow the hydrolysis of protein, fats, oils, and carbohydrates.

Endosome

The vacuole that contains the particle engulfed through phagocytosis.