Biology Mitosis and Meiosis Terms

Spindle Fibers

protein fibers that attach to the centromeres of chromosomes

Centromere

where microtubules attach themselves to on a chromosome

Sister Chromatids

two identical copies of the same chromosome formed by DNA replication, attached to each other by a centromere

Homologous Chromosome

pair of chromosomes with the same gene sequence… one paternal and one maternal

Chromatin

a mixture of DNA and proteins that form the chromosomes

Chromosome

threadlike structures made of protein and a single molecule of DNA

Centrioles

paired barrel-shaped organelles... near the nuclear envelope; spindle forms from

Nuclear Membrane 

a double layer that encloses the cell's nucleus

Centrosome

an organelle near the nucleus that contains centrioles and from which spindle fibers develop

spindle fibers start forming

Prophase

chromosomes line up along center of the cell

Metaphase

sister chromatids separate into individual chromosomes and are moved apart to opposite ends of the cell

Anaphase

chromosomes gather at opposite ends of the cell and decondense

Telophase

nuclear envelope breaks down

Prophase

chromatin condenses into chromosomes

Prophase

each chromosome is connected to a spindle fiber at its centromere

Metaphase

nuclear envelopes will reform

Telophase

cytoplasm pinches in half (division of cytoplasm)

Cytokinesis (technically separate from mitosis but I'm including it in here)

type of reproduction of mitosis

asexual

type of reproduction of meiosis

sexual

type of reproduction of binary fission, fragmentation and budding

asexual

Binary Fission

type of asexual reproduction where a parent cell divides, resulting in two identical cells; typically occurs in prokaryotes such as bacteria

Mitosis

type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus

Meiosis

type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell (the production of gametes)

Budding

type of asexual reproduction where the formation of an outgrowth (bud) from an organism; the bud is capable of developing into a new individual

Fragmentation

type of asexual reproduction or cloning, where an organism is split into fragments; each of these fragments develops into mature, fully grown individuals that are clones of the original organism

What is phase during the cell cycle when a cell grows, replicates DNA, and prepares for division?

Interphase

most of cell growth occurs during this phase

G1

DNA replication

S

prepares for cell division (by synthesizing organelles and molecules required for cell division)

G2

synthesis of new proteins and organelles for DNA replication

G1

results in 2 sets of chromosomes

S

The period of growth that occurs between cell division. _

Interphase

The series of events that cells go through as they grow and divide. _

Cell Cycle

Unwinding, base pairing and joining

3 main steps of DNA Replication

• The weak hydrogen bonds joining the nitrogenous bases in the middle of the DNA strand are broken by Helicase.

• The DNA strands pull apart and free DNA nucleotides begin to pair up with their complementary nucleotide on the parent strand with the help of DNA Polymerase.

• DNA ligase bonds Okazaki fragments on the 3’ to 5’ side to glue the strand of DNA together.

• 2 complete, identical sets of DNA are created; one for each of the 2 new cells.

DNA Replication steps