cell division & growth Flashcards
cellular differeniation
the specilaised adaptations of a cell to perform it’s function
chromosomes in human cells
humans have diploid chromosomes (paired) and their is 22 somatic pairs + 1 pair detemining sex (23pairs, 46 chromosomes)
zygotes
reproductive cells (eggs and sperm) which are haploid as they only contain 1 of the pair of chronomsomes
chronomosomes determining gender
X+X=girl, X+Y=boy (sperm determines gender as all egg cells have X chromosome)
stages of life cycle of a cell
Interphase (Growth 1 + Synthesis+ Growth 2 ), Mitosis, Cytokensis
interphase
cell spends most of its life here and carries out cells functions, is cyclis (as it moves from 1 stage to the next in order)
G1
newly formed cell grows to full size, replensished organelles and carries out it’s function
Synthesis
cell continues to carry out it’s function and DNA is used as template to be replicated
G2
cell continues to carry out function and prepares for cell division
mitosis
where a cell divides in 2 making 2 identical daughter cells (diploid making diploid cells), each idenitcal daughter cell gets 1 chromatid from each of the chromones in a pair
4 stages of mitosis
prophase, metaphase, anaphase, telophase
cytokinesis
the process where the cytoplasm divides to produce 2 new cells, occurs immdeiately after mitosiss and marks cell death and the beginning of a new cell cycle
meiosis
cell division producing zygotes as 1 diploid cell produces 4 haploid non-identical daughter cells (each daugter cell gets only 1 chromoid)
process of meiosis
1) chromosomes duplicate to form chromatids
2) 4 chromatids form a terad as they cross over causing mixing of genetic info
3) cell divides producing 2x diploid cells genetically different from parent
4) the 2 diploid duaghter cell then divides again to form 2 non-identical haploid daughter cells (no replication of DNA therefore each duaghter cells only gets 1 copy of a chromosome- not in pairs!)
cell organisation
specialised cells-> tissues -> organs -> organ systems
