Growth and development Flashcards
why are bacteria cells different from plant and animal cells?
they lack a ‘true’ nucleus, mitochondria and chloroplasts
what does the DNA look like in a bacteria cell?
a single circular strand or chromosome
Where is DNA found in a bacteria cell?
in the cytoplasm
what is the best measure of growth?
dry mass
what is the only way dry mass can be measure?
by killing the organism and driving off the water but it does measure the true growth of the whole organism
why do different parts of an organism grow at different rates compared to the whole organism?
because parts of the organism may be needed at different times during the life of the organism
what cells stay undifferentiated?
stem cells
what does undifferentiated mean?
that they can develop into different types of cells
how can stem cells be obtained?
from embryos
what can stem cells be used for?
medical conditions
why do people think extracting stem cells is wrong?
because embryos are destroyed
why do people think extracting stem cells is right?
because it can treat life-threatening diseases
what can embryonic stem cells do?
they can form a greater range of cell types and are easier to find
list some of the differences between plant and animal growth?
animals tend to only grow a certain size but plants carry on growing
plant cell division only happens in areas called meristems, found at the tips of roots and shoots
the main way that plants gain height is by cells enlarging rather than dividing
