D2.1 SL / HL Flashcards
Cell Theory
a scientific theory that states that all living things are made up of cells, and that all cells come from other cells
cellular division
the process by which a cell splits into two or more daughter cells
Binary fission
a type of asexual reproduction where a cell splits into two identical daughter cells
Mitosis
a process in which a cell’s nucleus divides into two identical nuclei, which then produces two identical daughter cells
Meiosis
a type of cell division that produces gametes, or sex cells, like sperm and eggs
daughter cells
cells that are formed when a parent cell divides
parent cell
a cell that divides to produce new cells, called daughter cells
Cytokinesis
the physical process that divides a cell’s cytoplasm into two daughter cells
multinucleated skeletal muscle cells
muscle fibers that contain more than one nucleus
Contractile ring
a ring-shaped structure that constricts a cell during cytokinesis, the final stage of cell division
cleavage furrow
an indentation in the surface of a dividing cell that separates the cell into two daughter cells
Vesicles
a small, fluid-filled sac within a cell that is bound by a membrane
cellulose
a natural polymer and carbohydrate that makes up the cell walls of plants
cell plate
a structure that forms in a plant cell during cytokinesis, separating the cytoplasm of two daughter cells
plasmodesmata
channels that connect plant cells, allowing molecules to move between them
Unequal cytokinesis
a type of cell division where the cytoplasm is divided unevenly, resulting in daughter cells of different sizes
Budding
a type of asexual reproduction where a new organism grows from a bud on a parent organism
Oogenesis
the process of creating female gametes, or ova, in the ovaries
polar body
a small haploid cell that is formed at the same time as an egg cell during oogenesis, but generally does not have the ability to be fertilized
Haploid
the presence of a single set of chromosomes in an organism’s cells
Diploid
the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair
Nuclear division
the process by which a cell’s nucleus divides before the cell itself divides
chromosomes
thread-like structures in the nucleus of cells that carry DNA, which contains genetic information
anucleated
a cell lacks a nucleus
reduction division
a type of cell division that reduces the number of chromosomes in a cell by half
recombination
the process of exchanging genetic material between or within chromosomes
centromere
a constricted region of a chromosome that helps divide DNA during cell division
chromatids
one of the two identical halves of a chromosome that has been copied in preparation for cell division
cohesin protein
a protein complex that holds together sister chromatids during cell division
replicated chromosomes
chromosomes that have been duplicated to create identical copies of themselves
Sister chromatids
identical copies of a chromosome that are joined at the centromere
histone
a protein in the nucleus of a cell that helps organize DNA into chromosomes and regulate gene activity
nucleosome
a DNA segment wrapped around a core of proteins, which is the fundamental unit of chromatin
Euchromatin
a loosely packed form of chromatin that is rich in genes and is often actively transcribed
heterochromatin
a chromosomal region that is dense and compact, and contains repetitive DNA sequences
microtubules (spindle fibers)
Long protein fibers called microtubules extend from the centrioles in all possible directions, forming what is called a spindle
tubulin
a protein that makes up microtubules, which are hollow tubes that help cells move and divide
MTOCs (microtubule organizing centers)
a structure found in eukaryotic cells from which microtubules emerge
kinetochore
large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters
interphase
the stage of the cell cycle when a cell grows, replicates its DNA, and prepares for cell division
G1 phase
the growth phase, where cells are provisioned with metabolites while most biosynthesis occurs
S phase
a stage of the cell cycle when DNA is copied
G2 phase
the second growth period of the cell cycle following DNA replication and preceding prophase, during which the cell forms the materials that make up the spindle
G0 phase
the phase in the cell cycle in which the cell is neither dividing nor preparing for division
Prophase
the first stage of cell division in mitosis and meiosis.It’s characterized by the condensation of chromosomes and the formation of the mitotic spindle
Metaphase
a stage of cell division where chromosomes condense and align in the middle of a cell
metaphase plate
an imaginary line that runs through the center of a cell during metaphase, a stage of cell division.Chromosomes line up along the metaphase plate, which is equidistant from the cell’s two poles
Anapahse
the stage of cell division when duplicated chromosomes separate and move to opposite ends of a cell
Telophase
the final stage of cell division in mitosis or meiosis, when chromosomes are separated into two new nuclei
homologous chromosomes
pairs of chromosomes in a cell that have the same genes in the same order, but may have slight variations
bivalents
a pair of homologous chromosomes that are connected by crossovers and sister chromatid cohesion
Crossing-over
the process of exchanging DNA between homologous chromosomes during meiosis
non-sister chromatids
chromatids that come from different homologous chromosomes
Random orientation
the random arrangement of homologous chromosomes during metaphase I of meiosis
Fertilization
the process when two gametes, or sex cells, fuse to create a zygote
diploid zygote
a fertilized egg cell that contains two sets of chromosomes, one from each parent
non-disjunction
a biological error that occurs when chromosomes fail to separate during cell division
Trisomy
a genetic condition where a person has three copies of a chromosome instead of the normal two
Monosomy
a condition where a cell or organism has one copy of a chromosome instead of the usual two
Trisomy 21 (Down syndrome)
a genetic condition that occurs when a person has an extra copy of chromosome 21
Chiasma
the point where two non-sister chromatids of homologous chromosomes touch
recombinant chromatids
chromatids that contain a combination of maternal and paternal genes
