Biology Chapter 12- Mitosis

Mitosis

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

Meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

cell cycle

The life of a cell from its formation to its own division or death.

Genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

Histones

protein molecules around which DNA is tightly coiled in chromatin

somatic cells (soma means body)

2N (diploid)

Gametes

reproductive cells (N) haploids

sister chromatids

DNA is replicated and still connected

How many chromosomes do humans have?

23 chromosomes but 46 total

Centromere

Region of a chromosome where the two sister chromatids attach

mitotic phase

stage of the cell cycle when a cell is actively dividing - consists of two phases.

Cytokinesis

division of the cytoplasm and organelles to form two separate daughter cells.

G1 Phase (Gap 1)

stage of interphase in which cell grows and performs its normal functions.

S (DNA Synthesis)

Results in each chromosome being composed of two sister chromatids. DNA replicates.

G2 Phase (Gap 2 Phase)

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

Mitosis phases in order

G1, S, G2, Cytokinesis

Cytokinesis

division of the cytoplasm to form two separate daughter cells.

Molecular control system

Regulates the eukaryotic cell cycle

How is plant cell cytokinesis different from animal cell cytokenesis?

plant cells deposit vesicules to form a cell plate, animal cells form a cleavage furrow.

G0

Which of the following is the correct order of events in the cell cycle?

G₁, S, G₂, mitosis, cytokinesis

The genetic material is duplicated during?

S phase

Alignment of the chromosomes at the equator of the spindle is characteristic of?

metaphase

. ______ occurs when sister chromatids separate?

anaphase

The mitotic spindle is a microtubular structure that is involved in?

separation of sister chromatids on homologous chromosomes

what is not a hallmark of prophase?

nuclear envelope is visible

Cyclin-dependent kinase (CDK) is

an enzyme that attaches phosphate groups to other proteins

Chromosomes are composed of

DNA and proteins

A normal human cell containing 44 autosomes and two Y chromosomes is a

somatic cell of a male

The two homologous chromosomes separate during

anaphase 1