Transcript asexual sexual repro 2014 show

REPRODUCTION
Sexual and Asexual
TWO MAIN PROCESSES
• Asexual Reproduction: only one parent is
needed, resulting in offspring that are
genetically identical to the parent
• Sexual Reproduction: requires two parents
who donate genes to the young, resulting in
offspring with a mix of inherited genes
Asexual Reproduction
• One parent produces genetically identical
offspring
– Used by many unicellular organisms, plants, and lower
animals
– each offspring has exactly the same heredity as its parent
– Usually rapid compared to sexual reproduction
– Requires much less energy to produce a new organism
Types of Asexual Reproduction
• Binary Fission: one cell divides into two
• Budding: one parent divides genetic information equally, but
cytoplasm unequally
• Sporulation: one parent makes spores which develop into offspring
• Regeneration: part of an organism can grow into a new organism
• Cloning: using genetic material from one organism to make a
genetically identical offspring
• Vegetative Propagation: part of a plant becomes a new plant
(runners, bulbs, cuttings, grafting)
Binary Fission
A form of Asexual Reproduction
• Simplest form of asexual reproduction
• Parent organism divides into two
• Approximately equal parts. Each daughter
cell becomes a new individual
Budding
Vegetative Propagation
A form of asexual reproduction
• part of a plant becomes a new plant (runners,
bulbs, cuttings, grafting, layering)
Regeneration
A form of Asexual Reproduction
• The ability to re-grow lost or damaged body
parts
• Example: Hydra, planaria, starfish, and
earthworm
• More complex animals less able to re-grow
parts. Crab can re-grow a claw. Some reptiles
can re-grow a tail. Most mammals can repair
damaged tissue but can not re-grow missing
parts.
Sporulation
• Spore Formation – spores
• Small specialized cells that contain a nucleus
and cytoplasm surrounded by a thick outside
wall which protects the spore
• Under the right conditions the spore can rise
to a new organism
• Found in bacteria, molds, yeast, mushrooms,
mosses, ferns and some protozoans.
On your own paper, make a graphic organizer on asexual reproduction: using
the processes of binary fission, budding, vegetative propagation and
regeneration.
Sexual Reproduction
Sexual Reproduction: requires two parents who donate
genes to the young, resulting in offspring with a mix of
inherited genes.
Sperm (male genetics) + Egg (female genetics) = Zygote
23 chromosomes
+ 23 chromosomes = 46
1 of the 23 chromosomes in each gamete is responsible
for sex determination of the offspring
Sperm= 1 sex chromosome (X or Y)
Egg = 1 sex chromosome (X or X)
Offspring can be XY (male) or XX (female)
Sexual Reproduction
male gamete
• Male Gamete
– Male sex cell
– Male germ cell
– Sperm
• Sperm facts
– Carry 23 chromosomes
– 1 responsible for the sex of the offspring
• Can be Y chromosome – determines male offspring
• Can be X chromosome – determines female offspring
Sexual Reproduction
Female gamete
• Female Gamete
– Female sex cell
– Female germ cell
– Egg
• Egg facts
– Carry 23 chromosomes
– 1 responsible for the sex of the offspring
• Can be X chromosome
Fertilization
• the union of an egg and sperm
• The result of this union is the production of a
zygote, or fertilized egg
Fertilized Egg - Zygote
• two parents donate genes to their young,
resulting in offspring with a mix of inherited
genes. These genes are donated through a
process called fertilization.
Day 5 after
fertilization