DNA Flashcards
(14 cards)
what does the nucleus contain?
genetic material in the form of chromosomes
what are chromosomes?
coiled up DNA molecules
what dooes chromosomes carry?
larfe number of genes,
-different genes control development of different characteristics e.h hair colour
what are body cells made up from?
2 copies of female and male chromosomes
hoow many chromosimes make up a human?
23 pairs = 46
when cells divide what is the name of this process?
mitosis
what do multicellar organisms use mitosis for?
grow or replace damaged cells
how does a cell grow and replicats DNA before mitosis?
-DNA spreads out into LONG STRINGS
-before it divides cell grows to increas amount of SUBCELLULAR STRUCTURES e.g mitochondria
-then DNA duplicates forms 2 seperate arms = X chromosomes
explain the process of mitosis?
-2 arms get pulled apart to opposite ends/poles
-membranes form around each set of chromosomes
-(becomes new nuclei)
=lastly cytoplasm & cell mebranes divides
==== produced 2 idenctical duaghter cells
(same DNA)
-
whats binary fisson?
-circulare DNA & PLASMIDS replicate
-cells gets bigger
-circular DNA strands move to opposite poles
-cytoplasm begins to divide - new cell walls form
-cytoplasm divids = 2 new daughter cells produced
from binary fission what does each daughter cell contain?
-one copy of circular DNA & various number of plasmids
how do prokaryotic cells replicate/divide?
binary fission
how often do bacteria cells divide?
mean time is 30 mins
how can u cacualate mean amount of diviosons?
-time / mean divioson time
-2 ^n of step 1
