UNITS 4 Cell Communication & Cell Cycle

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size.

somatic cell

Any of the cells of a plant or animal except the reproductive cells.

sister chromatids

Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.

centromere

The region of the chromosome that holds the two sister chromatids together during mitosis.

centriole

In animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions.

cell cycle

Series of events that cells go through as they grow and divide.

mitosis

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes.

cytokinesis

Division of the cytoplasm to form two separate daughter cells.

interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases.

metaphase plate

Plane midway between the two poles of the cell where chromosomes line up during metaphase.

cleavage furrow

The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.

cell plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

cancer

Any malignant growth or tumor caused by abnormal and uncontrolled cell division.

asexual reproduction

One parent produces a genetically identical offspring by mitosis.

denaturation

In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. In DNA, the separation of the two strands of the double helix.

chlorophyll

Green pigment located within the chloroplasts.

granum

Stack of thylakoids.

thylakoid

Flattened membranes in the chloroplast where the light reactions take place.

light reaction

Part of photosynthesis that involves light. ATP and NADPH are produced. Takes place on the thylakoid membrane.

oxidizing agent

Accepts electrons and becomes reduced.

reducing agent

Donates electrons and becomes oxidized.

calvin cycle

Carbon fixation process in photosynthesis. Forms sugar and other organic compounds.

rubisco

The most abundant protein on earth. Performs Carbon Fixation in the Calvin Cycle.

transduction

The binding of the signal molecule changes the receptor protein in some way.

chromatin

The complex of DNA and proteins that makes up a eukaryotic chromosome.