producing new cells Flashcards
mitosis function
when parent cell divides to produce 2 identical tissues
diploid
2 matching sets of chromosomes
cell division
provides new cells for growth, repairs damaged tissues and replaces dead or damaged cells
chromatid
2 threads in chromosomes that have replicated info
explain chromosome compliment
haploid is single with half the number of cells in a diploid cell
diploid cell 2 matching sets of chromosomes which is double the cells in haploid
to obtain full set of genetic info…
each daughter cell has same diploid chromosome complement as original parent cell
stage 1
- chromosomes appear as fine threads through nucleus
- each chromosomes double to become chromatid
stage 2
- chromosomes continue to shorten
- 2 identical chromatids joined at centromere
stage 3
- chromosomes line up at equator
- nuclear membrane disappears
stage 4
- chromatids pulled apart by contraction of spindle fibres
stage 5
- chromatids are the new chromosomes and clump together at poles of new cells
- nuclear membrane forms
stage 6
- cytoplasm divides
- chromosomes become less distinct
- 2 new daughter cells formed
stem cells
UNSPECIALISED cells which can divide indefinitely to self-renew
- involved in growth and repair of damaged tissues
- potential to become and type of cell in body
embryonic stem cells
give rise to all cells in animal body
hierarchy
cells –> tissues –> organs –> systems
specialised plant cell + function + feature
- root hair cell, absorbs water from soil, long finger like projections
- guard cells, control opening and closing of stomata, sausage shaped with chloroplast
- epidermal cells, protection, thin flat and transparent
- mesophyll cells, site of photosynthesis, contain chloroplasts
animal cell + function + feature
- red blood cell, transport oxygen, biconcave no nucleus haemoglobin large sa
- neurons, carry nerve impulses to diff body parts, long axon
- ovum, carries genetic info and fuses w sperm cell to produce zygote, composed of cytoplasm
- sperm cells, carries genetic info, tail allows sperm to swim
- stem cells, divide to produce new cells that become specialised, unspecialised cells capable of repeatedly dividing
tissues
similar specialised cells which group together to preform particular function
organs
tissues working together to form an organ which will preform specialised task
system
organs which work together to carry a particular job
why does the new cells produced have to be identical to original cell
so no genetic info lost and have full set of instructions for growth and development
