Transcript Animal Reproduction and Development

Animal Reproduction and
Development
Reproduction Song
Animals reproductive by asexual and sexual methods:
•Asexual is the production of offspring with genes all from one
individual, without the fusion of gametes.
•Sexual involves formation of gametes and fertilization, genetic
variation
Asexual Methods Include:
Budding in Hydra
Gemmules in Sponges
Starfish Regeneration
Parthenogenesis: an unfertilized egg develops
Honey bees: drones are males and are produced
parthenogeneticly and female workers and queens form from
fertilized eggs.
Queen
Worker (female)
Drone (male)
Sexual Reproduction
Hermaphroditism: individual has both male and female
reproductive systems
Earthworm
Fertilization can occur externally or internally
Aquatic animals tend to be external
Terrestrial animals tend to be internal
Development can be external in the water, external on land,
or internal.
Oviparous: lay eggs, Amniotic eggs are terrestrial eggs
Ovoviparous: live birth from eggs (some sharks and
snakes)
Viviparous: live placental birth
What are the adaptive values of each style off sexual animal
reproduction?
Number of Eggs: ?
Parental Care: ?
Habitat: ?
Introduction to Reproduction System
Complete the type of sexual reproduction typical of each group
Vertebrates
Fish
Amphibian
Reptile
Bird
Mammal
Fertilization
Development
Parental Care
Reproductive System of the Human Male
Male Reproductive System video
Male Reproductive System detailed video
The male reproductive
system produces sperm
cells and provides a
mechanism for delivering
them to the female's body.
Identify the role
of:
Testes
Epididymis
Vas deferens
Scrotum
Outline the functions of the male reproductive organs
Vasectomy Surgery video
Hormonal
control of the
Testes
Development of Eggs and Sperm
Spermatogenesis
Meiosis produces
gametes in the
seminiferous
tubules.
Close up look at
seminiferous tubules
video
Seminiferous Tubules synthesize sperm
Sperm cells
Sperm Structures
Female Reproductive System
Female Reproductive System
Female Reproductive System video
Ovary
Follicle
Oogenesis
This is the state of the egg
when fertilized
Stages of
Development in
the Ovary
Ovarian Cycle video
Identify the
stages of the
cycle
What
happens in
the ovary,
uterus, and
pituitary
glands?
Uterine Cycle video
Menopause: cessation
of cycle, ages 46-54,
ovaries lose response
to FSH & LH
Formation of the zygote and early post-fertilization events
Cleavage occurs over several days following
fertilization. The zygote divides as it travels through
the oviduct. By the time the cilia of the oviduct
deliver the embryo to the uterus, the embryo is a ball
of cells called a blastocyst. The blastocyst implants
in the endometrium.
A blastocyst forms nearly a
week after fertilization
Four membranes
protect and nourish the
embryo, which consists
of three tissue layers.
Nutrients and waste products are exchanged between the fetus and the
mother within the placenta. The umbilical vein (red) carries oxygen-rich
blood and nutrients to the fetus. The umbilical arteries are blue,
indicating that they carry oxygen-depleted blood and waste products
away from the fetus.
Placental circulation: materials are exchanged by diffusion,
active transport, and selective absorption. Not by direct blood
contact.
Structure and function of the placenta video
Human fetal development:
Amniotic Sac
5 weeks
Blood Incompatibility video
14 weeks
20 weeks
Hormonal induction of labor
Name the structures and its role in reproduction and metabolism
Name the structures and its role in reproduction and metabolism
Name the phases and
state of the organs.
Name the hormones:
Black:
Red:
Blue:
Green:
Animal Development
Epigenesis: animal
emerges gradually
from the egg
Preformation: shows
infant in sperm from
1694 engraving
“homunculus”
Fertilization in Mammals
Zona pellucida
Changes that occur in the egg after fertilization video
Cleavage partitions the zygote into many smaller cells
Rapid cell division without growth produces cells called
blastomeres.
• In both sea urchins and frogs first two cleavages are
vertical.
• The third division is horizontal.
• The result is an eight-celled embryo with two tiers of four
cells.
• Continued cleavage produces the morula.
• A blastocoel forms within the morula  blastula
View the sea urchin development video on the CD
Gastrulation rearranges
the blastula to form a threelayered embryo with a
primitive gut
Development after fertilization video
(triploblastic)
Organogenesis forms the organs from the three embryonic
germ layers
Organogenesis in a frog embryo
View frog development video on CD
Amniote embryos develop in a fluid-filled sac within a
shell or uterus
The amniote embryo is an adaptation for reproduction in the
terrestrial environment.
Shelled eggs of reptiles and birds.
Uterus of placental mammals.
Extraembryonic membranes in a chick
Identify the membranes that provide supporting functions
Protection from
mechanical
shock
Gas exchange
Disposal of uric
acid
Nutrient source
Extraembryonic membranes in a chick
How extraembryonic membranes support chick video
• The four extraembryonic membranes are the yolk sac,
amnion, chorion, and allantois.
– Cells of the yolk sac digest yolk providing nutrients to the
embryo.
– The amnion encloses the embryo in a fluid-filled amniotic
sac which protects the embryo from drying out.
– The chorion cushions the embryo against mechanical
shocks.
– The allantois functions as a disposal sac for uric acid.
Chick embryo 54 hours old
Most major organs have
formed
Formation of structures in embryo video
Early development of a
human embryo and its
extraembryonic
membranes
 Embryonic membranes – homologous with those of
shelled eggs.
 Chorion: completely surrounds the embryo and other
embryonic membranes.
 Amnion: encloses the embryo in a fluid-filled amniotic
cavity.
 Yolk sac: found below the developing embryo.
 Develops from the hypoblast.
 Site of early formation of blood cells which later
migrate to the embryo.
 Allantois: develops as an outpocketing of the
embryo’s rudimentary gut.
 Incorporated into the umbilical cord, where it forms
blood vessels.
• Organogenesis begins with the formation of the neural
tube, notochord, and somites.
Embryonic membranes – homologous with those of shelled eggs.
Impact of Drugs and Chemicals on Fetal Development video
During labor, hormones stimulate the uterus to contract. The
contractions push the baby out of the mother's body.
The Process of Birth