quiz 2 bio (2.6-2.12) Flashcards
what is a chromatin
- thin thread of dna like pile of spaghetti
- found in cell nucleus
- condenses to form chromosomes
what are chromosomes
- condensed chromatins (condensed dna)
what are chromatids
- half of a chromosome (when chromosome splits into two chromatids during cell division)
chromatin during cell division
when cells divide..
- chromatin condenses to form chromosomes
- chromosomes split into two chromatids
- chromatid becomes chromosome in their new cell
how many chromosomes do humans have
46 in total, 23 pairs
diploid definition
containing two complete sets of chromosomes, each parent contributing one chromosome to the pair. result of sexual reproduction
haploid definition
having half of 23 pairs of chromosomes (ex. egg cell or sperm cell)
zygote definition
-a fertilized egg
- is a diploid
longest phase of cell cycle?
interphase (around 80%)
stages of mitosis?
prophase, metaphase, anaphase, telophase
what happens during prophase?
- nuclear membrane disappears
- nucleolus disappears
- spindle fibres grow out of centrioles, attach to centromeres
- centrioles move to opposite sides of cell
- chromosomes get thicker
sister chromatids definition
duplicated chromosomes attached with a centremere
centromere definition
part where sister chromatids join
what happens during metaphase?
- spindle fibres pull chromosomes to middle of cell
- checks that chromosomes are in a line and attached to spindle fibres
what happens during anaphase?
- centromeres separate and daughter chromosomes are pulled to centrioles by spindle fibres
daughter chromosome definition
when sister chromatids separate and become individual structures (during anaphase)
what happens during telophase?
- nuclear membrane forms again
- nucleolus reappears
- daughter chromosomes become chromatin
what happens during cytokinesis?
- occurs right after mitosis
- cell membrane pinches together and forms two identical daughter cells
how does mitosis + cytokinesis in plant cells work
- plants lack centrioles but still have spindle fibres
- vesicles from golgi bodies fuse in the middle of cell to form a cell plate which has materials to create a cell wall and separate daughter cells
what is cancer
uncontrolled growth of abnormal cells
what is the branch of medicine dedicated to cancer called
oncology
how are cancer cells different from normal cells?
- cells don’t listen to apoptosis signals, keep dividing
- cancer cells grow to rapidly to have a specialized function
- cannot be identified by immune system as abnormal
what is a tumour suppressor gene
- prevent uncontrolled cell growth
- faulty tumor suppressor genes can lead to cancer and tumours
what are hereditary mutations
- cell mutations passed down from parents
- mutation is present in all cell of body for whole life