BIOLOGY 3.4

Cell Cycle

causes cell to divide into 2 daughter cells

cell division

Examples of Meiosis and Mitosis. used to make more cells and divide existing cells

cell plate

during cytokinesis a ______ forms to create a wall between the two daughter cells

centrosomes

Help assemble microtubules, used to move chromosomes during cell division

centriole

one of a pair of small cylindrical cell organelles near the nucleus in animal cells

nucleotide

the basic structural unit of nucleic acids

homologous chromosomes

control the same hereditary traits

centromere

a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape

chromatin

the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins

chromosome

a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order

sister chromatids

two identical chromatids

diploid number

cells containing 2 copies of each chromosome

haploid number

half of total chromosome number

cell cycle checkpoints

G1, R, S, G2, M (in order)

cyclins

a family of regulatory proteins that control the progression of the cell cycle

mutation

any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism

Proto-oncogenes

control timing of cell division

oncogenes

allows unlimited cell division

tumor suppressor gene

a suppressor gene that blocks unscheduled cell division

tumor

an abnormal new mass of tissue that serves no purpose

benign

not dangerous to health; not recurrent or progressive

malignant

dangerous to health; characterized by progressive and uncontrolled growth

cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division; it may spread to other parts of the body through the lymphatic system or the blood stream

carcinogen

any substance that produces cancer