Chapter 10 - Cell division Flashcards
anaphase
chromatid pairs are pulled away by spindle fibres to opposite poles.
anaphase 1
homologous chromosomes separate. the sister chromatids are not identical as of the allel exchange.
anaphase 2`
sister chromatids separate
benign
not able to spread to other parts of the body
cancer
uncontrolled division of the cells
carcinogen
environmental factors that can cause cancer, if they damage DNA it can lead to mutation that results in uncontrolled cell growth and division. UV, smoking tobacco, viruses like HPV
cell cycle
events that take place from one cell division to the next. (interphase and mitotic phase)
chiasma
point at which crossing over occurs between chromatids. sig. in prophase 1 where recombination happens
crossing over
interchange of parts of chromatids of a homologous pair of chromosomes - creates new combination of alleles
cytokinesis
division of cytoplasm to form 2 daughter cells
diploid
46 chromosomes, 26 pairs of homologous chromosomes`
down syndrome
trisomy 21. Altered physical appearances, intellectual disability.
fertilisation
fusion of sperm and egg`
Gamete
sperm or ova
haploid number
23 chromosomes - one chromosome from each homologous pair
homologous chromosomes
pairs of chromosomes - similar in shape, size and gene that control same characteristics
independent assortment
random separation of the homologous chromosomes - separation doesn’t affect the separation of the other homologous chromosomes
interphase
stage where DNA molecules deplicate
Meiosis
type of cell division resulting in gametes (4 genetically different haploid cells from one diploid cell)
Metaphase
chromosomes line up at the equator of the cell
Malignant tumour
Able to spread to other parts of the body
Metastasis
Happens with malignant tumours, spreading of tumour cells to form secondary tumour in different parts of the body
mitosis
division of the nucleus, daughter nuclei have the same DNA as the parent cell
monosomy
only one copy of a chromosome instead of 2
non-dijunction
one or more of chromosome pairs fail to separate during meiosis
partial monosomy
part of a chromosome missing
partial trisomy
part of an extra chromosome
prophase
first stage of mitosis. Chromosomes become visible, spindle fibres form, nuclear membrane breaks down
prophase 1
in meiosis. recombination happens, exchanging segments of alleles between the paternal and maternal chromosomes. chromosomes visible, nuclear membrane breaks down etc
prophase 2
nuclear membrane disappears, spindle fibres form.
Secondary tumour
cancer that has spread from the original tumour - refers to malignant tumour
S phase in interphase
Synthesis phase where the DNA molecules duplicate
telophase
final stage of mitosis. daughter chromosomes group at opposite poles of the cell, nuclear membrane reforms, cell membrane begins to pinch inwards
trisomy
individual inherits an extra copy of a chromosome
tumour
abnormal mass of tissue resulting from an uncontrolled division of abnormal cells.
causes of cancer
genetic, unknown, certain carcinogens cause different types of cancer
importance early detection of cancer
treatment can occur at early stages of tumour growth, improves chance of successful treatment and recovery
cervical cancer
caused by human papillomavirus when it causes abnormal cervical cells to develop. Pap smear test to examine cervical cells for abnormalities that could develop into cancer
breast cancer
formed from uncontrolled division and replication of abnormal cells in the breast. Mammography scan
bowel cancer
in the colon or rectum in the large intestine. laboratory analysis of faeces for blood as most bowel cancers develop from polyps (polyps can bleed when they have been irritated)
prostate cancer
found in the prostate gland. biopsy is performed on tissue taken from the prostate gland when blood test (shows presence of a particular protein that is produced by prostate cancer) or physical examination (doctor feels prostate gland through the anus for any irregularities) shows the possibility of prostate cancer
