Biology Ch 2
What is a stem cell?
undifferentiated cell that can differentiate into one or
more specialised cell types
What are adult stem cells?
stem cells from adults that can only differentiate into
certain specialised cells
What are embryonic stem cells?
stem cells from embryos that can differentiate into any
specialised cell
What is therapeutic cloning?
patient’s cells are used to create an early embryo clone
of themselves – stem cells from the embryo can then be
used to treat the patient’s medical conditions
What is cell division by mitosis?
body cells divide to form two identical daughter cells
What is the purpose of mitosis?
growth and repair of cells, asexual reproduction
What happens during the first stage of the cell cycle?
cell grows bigger, chromosomes duplicate, number
of subcellular structures (e.g., ribosomes and
mitochondria) increases
What happens during mitosis?
one set of chromosomes is pulled to each end of the cell
and the nucleus divides
2nd stage of the cell cycle
What happens during the third stage of the cell cycle?
the cytoplasm and cell membrane divide, forming two
identical daughter cells
What happens during stage 1 of the cell cycle?
increase in number of sub-cellular structures, such as ribosomes and mitochondria.
cell grows bigger
DNA replicates (chromosomes are duplicated)