Biology Unit 8, Cell Division, All Key Terms

cell division

cells split to create more cells

mitosis

asexual cell division; cells split to form 2 exact copies

parent cell

original cell before cell division

daughter cell

two new cells that result from mitosis

replication / duplication / reproduction

process of making a copy

surface area

measurement of the outer surface of an object

volume

Amount of space inside an object

surface area to volume ratio (SA:V)

comparison of surface area to volume of an object like a cell; as objects grow, volume grows faster than surface area

sexual reproduction

new cells or organisms are created using 2 parents or parent cells

asexual reproduction

new cells or organisms are created from 1 parent or parent cell

gamete

sex cells created by meiosis such as sperm and egg

meiosis

sexual cell division; cells split to form gametes (sex cells) with 1/2 a copy of the parent's DNA

zygote

a fertilized egg

chromosomes

threadlike structures made of chromatin (condensed DNA)

chromatin

clusters of DNA and proteins found in the nucleus

somatic cells

body cells; any cells in the body except gametes (sex cells)

centromere

spot on chromatids where sister chromatids attach; spindle fibers attach here during mitosis

chromatid

1 of 2 "sister chromatids" of a duplicated chromosome

sister chromatids

joined copies of the original chromosome

plasmid

circular piece of DNA located in many prokaryote cells

centrioles

in animal cells, an organelle that aids in cell division by attaching to spindle fibers

centrosome

in animal cells, an organelle that splits into 2 centrioles before cell division

spindle fibers

strings of protein that pull chromatids apart during cell division

cell equator

middle of a cell that is in the process of dividing; where chromosomes line up during cell division

poles (of a cell)

opposite ends of a cell during cell division; where chromatids go during the last phases of cell division

cytokinesis

movement of organelles and cytoplasm to daughter cells, during the last phases of cell division

cell plate

a wall that forms between 2 dividing plant cells

apoptosis

programmed cell death

cyclins

proteins that control the timing of the cell cycle

internal regulators

proteins that respond to events inside the cell; they help control the timing of the cell cycle

external regulators

proteins that respond to events outside the cell; they help control the timing of the cell cycle

mutation

change or error in DNA

mutagen

something that causes mutations in DNA

cancer

uncontrolled cell division or growth

metastasis

spread of cancer cells beyond the original tumor

galls

tumors in plants

cell differentiation

cell become specialized for a specific function

stem cell

cell that are NOT yet specialized and can become any type of specialized cell

p53 protein

stops the cell cycle if DNA is damaged

carcinogen

cancer-causing substance

totipotent stem cells

stem cells that can become any type of cell including placental cells;

pluripotent stem cells

stem cells that can become any type of cell in the body but not placental cells

multipotent stem cells

stem cells that can become any of a few cell types

induced stem cells

any cells that have been reprogrammed to be stem cells, by scientists