Cell Division Chp14 Flashcards
What is cell continuity
means that all cells develop from pre-existing cells
What is a chromosome
coiled threads of DNA and protein that become visible in the nucleus at cell division
What is a gene
a section of DNA that contains instructions for the formation of a protein
What is a haploid cell
a cell with one set of chromosomes
What is diploid cell
a cell that has 2 sets of chromosomes
What is a homologous pair
two chromosomes of similar size with the same sequence of genes
What is the cell cycle
the changes that take place in a cell during the period between one cell division and the next
What is interphase
the phase in the cell cycle when the cell is not dividing
What is mitosis
a form of nuclear division in which one nucleus divides to form two nuclei, each containing the same number of chromosomes with identical genes
Function of mitosis in unicellular organisms
reproduction
Function of mitosis in multicellular organisms
growth and repair
What is cancer
a group of disorders in which certain cells lose their ability to control both the rate of mitosis and the number of times mitosis takes place
`What is a benign tumour
when the cells stop dividing after some time
What is a malignant tumour
the uncontrolled multiplication of abnormal cells
Causes of cancer
carcinogens (cigarette smoke, ultraviolet radiation, pesticides)
What is meiosis
a form of nuclear division in which the four daughter nuclei have half the number of chromosomes as the parent nuclei
Function of meiosis
allows for variation and sexual reproduction
Phases of mitosis
Prophase, metaphase, Anaphase, Telophase
What happens in prophase
spindle fibres form, nuclear membrane and nucleolus break down
What happens in metaphase
spindle fibres attach to the centromere, chromosomes line up at the equator
What happens in anaphase
spindle fibres contract pulling chromosomes to the poles
What happens in telophase
Chromatin form, nuclear membrane forms, spindle fibres breakdown, nucleolus forms
Cell division in animals
forms a cleavage furrow
Cell division in plant cells
vesicles form cell plate
