cell growth vocab

Cell Cycle

The process of cellular reproduction, occurring in three main stages:interphase (growth), mitosis (nuclear division), and cytokinesis (cytoplasm division).

Primase

Enzyme that adds a short segment of RNA, called an RNA primer, on each DNA strand as the helix unwinds.

Telomere

Protective cap made of DNA that is found on the ends of a chromosome.

Mitosis

In eukaryotic cells, a process of cell division that forms two new nuclei, each with the same number of chromosomes.

DNA Ligase

Enzyme that chemically links DNA fragments together.

DNA Helicase

Enzyme that unwinds and unzips the double helix.

Cytokinesis

Third main stage of the cell cycle during which a cell's cytoplasm divides, creating a new cell.

Centrioles

Cell structures found in animal cells that help initiate the development of the spindle for mitosis.

Replication

Process of copying DNA prior to cell division.

Chromosome

In a eukaryotic cell, a structure in the nucleus made up of DNA and protein; in a prokaryotic cell, the main ring of DNA.

Interphase

First stage of the cell cycle during which a cell grows, matures, and replicates its DNA.

Cell Division

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

Sister Chromatid

Structure that contains identical DNA copies, formed during DNA replication, and joined at the centromere.

Chromatin

Relaxed form of DNA in the nucleus of a cell.

Centromere

The region of the cell structure that joins two sister chromatids and holds them together during mitosis.

Semiconservative Replication

Method of DNA replication in which parental strands separate, act as templates, and produce molecules of DNA with one parental and one new strand.

Prophase

First and longest phase of mitosis where the cell's chromatin condenses into visible chromosomes.

Metaphase

Second phase of mitosis where chromosomes line up across the center of the cell.

Anaphase

Third phase of mitosis where centromeres split, allowing sister chromatids to separate and become individual chromosomes.

Spindle Apparatus

A network of microtubules that appears during mitosis, helping guide chromatids to the ends of the cell.

Telophase

The last stage of mitosis in which nuclei reappear and two new nuclear membranes begin to form.

Cyclin

A family of closely related proteins that regulate the cell cycle in eukaryotic cells.

Cancer

A tumor in which cells begin dividing at an uncontrolled rate and become invasive.

Xylem

Vascular tissue that carries water upward from the roots in every part of a plant.

Phloem

Vascular tissue responsible for the transport of nutrients and carbohydrates produced by photosynthesis.

Nucleosome

Repeating subunit of chromatin fibers, consisting of DNA coiled around histones.

Epithelial

The thin tissue forming the outer layer of a body's surface and lining hollow structures.

Palisade Cells

Layer of tall, column-shaped cells just under the upper epidermis of a leaf.

Stomata

Openings in the underside of a leaf that allow carbon dioxide and oxygen to diffuse in and out.

Guard Cells

Specialized cells in the epidermis of plants that control the opening and closing of stomata by responding to changes in water pressure.

Okazaki Fragment

Short segment of DNA synthesized discontinuously in small segments in the 3' to 5' direction by DNA polymerase.

Asexual Reproduction

Process of reproduction involving a single parent that results in genetically identical offspring (e.g., budding, binary fission).

Synthesis

The production of chemical compounds by reaction from simpler materials.

Mutation

A change in the nucleotide-base sequence of a gene or DNA molecule.