1. Asexual Reproduction Genes all come from one parent
Common to many invertebrates
Advantages
Enables animals to live in isolation – no need to locate mates
Organism can create numerous offspring in a short amount of time – rapidly colonize habitat
Advantageous in __________, favorable environments
Perpetuates successful genotypes precisely

2. Forms of Asexual Reproduction
_____________
separation of parent into two or more individuals of approximately equal size.
new individuals split off from existing ones
__________________
Broken off body part grows into new individual
Regeneration of body parts
_________________
Eggs develop without being fertilized
Queen Worker Drone

3. Forms of Asexual Reproduction
Parthenogenosis
Egg develops ___________ being fertilized
Adults produced by parthenogenesis are _____________
Example: drone (male) bees form from single unfertilized egg and do not need to undergo meiosis to make their own new reproductive cells
SOMETIMES, in certain species, whether parthenogenesis occurs may be determined by season/conditions
Favorable conditions leads to asexual repro.
Everythings going well, why change?
Environmental stress leads to sexual repro
If conditions are bad, better hope some variety will come up with a solution!

4. Sexual Reproduction
Creation of offspring by fusion of haploid gametes to form a zygote
Increases genetic variation
Probably enhances reproductive success when pathogens or other environmental factors ________ rapidly
If there’s variety, chances are better than someone will have a genetic solution to an environmental problem

5. Hermaphrodites
Each individual has both male and female reproductive systems
NOT ASEXUAL
Helps when finding a mate is not easy
Every individual encountered is a potential ___________ (as opposed to just ½ the individuals encountered)
Each partner donates sperm to female repro organs of the other.

6. TWO Types of Fertilization
Requires environment where egg/zygote can develop without drying out.
The eggs are unprotected and vulnerable to water loss, etc.
Thus, almost always occurs in ____________ areas

7. External Fertilization
Parents may not even make physical contact
Eggs/sperm released into water
Timing is still important
Some do use specific mates and mating behaviors
__________________ are used to draw animals together

8. External Fertilization
GENERAL rule
_______ of zygotes produced
_________ parental care
Have lots of babies and hope at least a few of them survive
Very small proportion of zygotes survive to full development

9. Internal Fertilization
Protects _________________
Neither sperm nor egg is ever exposed to environment
Sperm placed directly inside the female
Protects _______________
Embryos develop either:
Inside shelled eggs
Inside the female
Don’t come out until they can survive dry environment

10. Internal Fertilization
ALL internal fertilization requires
Sophisticated reproductive systems including organs that
deliver sperm
receptacles that receive, store and transport sperm to ripe eggs.
Cooperative behaviors leading to copulation
Uncharacteristic sexual behaviors are eliminated by ____________________________
Example – female spiders eat males if they don’t use the proper reproductive signals

11. Internal Fertilization
Generally produces _______________ zygotes than external
But proportion of zygotes that develop and survive is ____________. This is because of:
greater protection of eggs/zygotes/embryos
Within a shell OR
Within the female
Due to better parental care of eggs and offspring
Don’t abandon young

12. Internal Fertilization
Two possible outcomes:
_______________ to be laid on land
Reptiles, Birds
And 1 very small mammal group – montremes (platypus and spiny echidna)
Embryos develop _______________________
Mammals (placental and marsupial)
Both animal types are called ______________ due to the embryonic structures they share in common

13. AMNIOTES Amniotic eggs Shell is NOT the only part that protects
EXTRAEMBRYONIC MEMBRANES make the anmiontic egg successful
AMNION
surrounds baby with water
“little ocean”
Yolk Sac
Stored Food
Allantois
Waste sac
Chorion
Functions with allantois in GAS EXCHANGE

14. AMNIOTES Internal Development Mammals – Shelled egg not used, but
Amnion
Internal Development
Mammals –
both placental and marsupial
NOT monotremes (EGG LAYERS!)
Shelled egg not used, but
amnion present and
________ extraembryonic membranes give rise to ____________, etc.

15. Male Reproductive Organs
Testes
Seminiferous Tubules
Sperm production
Epididymis
Sperm maturation
Vas Deferens
Carry sperm to urethra
Urethra
exit body

16. Cross section through Sem. Tubule
Seminiferous Tubules
Highly coiled tubes
Sperm are formed HERE
____________ HAPPENS HERE!!
Also contain cells (Leydig cells) which make male hormones
Testosterone and other androgens
Cross section through Sem. Tubule

17. ___________________________
General term for creation of gametes
SEX CELLS
___________________
TWO TERMS
Spermatogenesis
Gametogenesis (meiosis) in males
Oogenesis
Gametogenesis (meiosis) in females

18. Spermatogenesis – MEIOSIS to create sperm
Least Mature
Also called
spermatogonium
Epididymis
Testis
Germ cell
(diploid)
Coiled
seminiferous
tubules 1°
spermatocyte
(diploid)
MEIOSIS I 2°
spermatocytes
(haploid)
MEIOSIS II
Vas deferens
Spermatids
(haploid)
Meiosis happens
Inside
Seminiferous
tubules
Most Mature
Spermatozoa
Cross-section of
seminiferous tubule

19. Spermatogenesis __________________________ Products of meiosis
____ created from each primary spermatocyte
____________________
Immature sperm
Tailess
Sertoli cells
Provide nourishment to spermatids as they further develop into sperm at center of seminiferous tubule

20. Mature Sperm Sperm structure Head Mid-piece Tail ___________________
Contains enzymes to penetrate egg
Nucleus
Males genetic contribution
Mid-piece
Mitochondria
For energy - swimming
Tail
Microtubules
____________

21. Fertilization Joining of sperm & egg sperm head (nucleus) enters egg

22. Female reproductive system
Ovaries
produces eggs & hormones
Uterus
nurtures fetus; lining builds up each month
Fallopian tubes
tubes for eggs to travel from ovaries to uterus
Called OVIDUCTS in every other animal
Cervix
opening to uterus, dilates 10cm (4 inches) for birthing baby
Vagina
birth canal

23. Female Reproductive Organs
Ovaries
Each ovary contains many follicles
___________________
One egg cell surrounded by follicle cells
Follicle cells nourish and protect developing egg
Follicle cells also produce primary female sex hormones
estrogens

25. Oogenesis Oogonia Primary oocyte Secondary oocyte ____________
Cells that create cells that undergo ________
________________
Repeatedly divide to create _______ oogonia
______________
Primary oocyte
Cell that has entered into _____________
Secondary oocyte
____________

26. Oogenesis ________ divisions
Make one really good egg and ___ polar bodies
Meiosis 1 completed
during egg maturation
ovulation
Meiosis 2 completed
triggered by fertilization

27. Reproductive hormones
LH & FSH
______________
from testes
functions
sperm production
2° sexual characteristics
_____________
from ___________
egg production
prepare uterus for fertilized egg
testes or ovaries