Transcript SEXUAL & ASEXUAL REPRODUCTION INVOLVE CELL DIVISION

SEXUAL & ASEXUAL
REPRODUCTION INVOLVE
CELL DIVISION
• ASEXUAL REPRODUCTION INVOLVES
ONE PARENT: through binary fission,
budding, & regeneration
– One organism makes 1 or more new organisms
that are identical to itself & live independently
of it. Are genetically identical.
• SEXUAL REPRODUCTION INVOLVES 2
PARENT ORGANISMS
ASEXUAL REPRODUCTION
• Binary fission occurs in prokaryotes; interphase &
cytokinesis, but no mitosis (because no nucleus).
Parent organism splits in 2, making 2 genetically
identical, independent daughter cells. Since all
prokaryotes are single-celled, cell division &
reproduction by binary fission are the same thing.
• Budding occurs in both uni- & multi-cellular
organism. Buds form on a part of the body as a cell
with the same genetic material as the parent. It
grows until it forms a complete or nearly complete
new organism identical to the parent. Usually it will
break off & be independent.
• Some yeast cells & single-celled organisms
reproduce asexually by budding. But most occurs in
multicellular organisms (hydras & kalanchoe plant)
ASEXUAL REPRODUCTION
• REGENERATION: the
process of new tissue
growth at the site of a
wound or lost limb.
• This can be asexual
reproduction (starfish cut
in half form 2)
• Plant cuttings can form
identical independent
plants.
• GENERATION TIME:
time it takes for one
generation to produce
offspring.
• For bacteria, this is less
than 30 minutes; so in 1
hour bacteria can increase
to 4X the original
number.
• This is why you can get
sick so quickly from
them.
• Rare genetic changes are
more likely to occur in
bacteria due to gener.time
SEXUAL V. ASEXUAL
REPRODUCTION
• Reproduction of
multicellular organisms
often involves sexual
reproduction & asexual
cell division.
• If you grow a plant from
a cutting, the new plant
will be genetically
identical to the parent.
But if plants grow from
seeds they have DNA
from 2 parents (sperm &
egg unite) and may look
different from one parent.
• Cell division is part of
both sexual & asexual
reproduction.
• Mitosis produces cells
identical to parent cells.
• Diversity of life on Earth
due in part to combining
genetic material from 2
parents in sexual
reproduction.