How do prokaryotes reproduce?
Cloning process, one cell divides and give two identical cells.
How do eukaryotes reproduce?
What is budding or fission?
When an animal produces a copy of itself without embryonic development
What is pathogenesis?
An unfertilized egg develops into an embryo
What is sexual reproduction?
Union of male and female gametes. Two haploid sets of chromosomes that combine to form a new diploid set of chromosomes
What are homologous chromosomes?
A matched pair with one member of each pair from mother and father.
What are gametes?
Sperm and eggs that contain one member of each homologous pair (haploid number)
How is gamete cell division accomplished? Meiosis or meitosis?
Meiosis. -ONly one of the two sets of homologous chromosomes is distributed to daughter cells (haploid). -Each sperm and oocyte has a unique compliment of chromosomes
Reproductive strat: R-selected reprod. K-selected reprod. Intermediate.
R-selected reprod- Many offspring with no parental care and minimal nourishment. K-selected reprod- Relatively few offspring, most parental energy used for nourishing and protecting offspring. Intermediate- Some nourishment and parental care. (fish protecting hundreds of eggs)
Describe oviparous sexual reproduction.
Young develop in eggs after expulsion from mothers body. ex) fish and amphibians ovi=egg, parous=produced
describe Ovoviviparous sexual reproduction
Production of eggs that use yolk to develop partly or fully within the body of mother ex)birds. Offspring are born live. Vivi=live
Describe viviparous sexual reproduction
Production of young within the mother's body that use maternal blood nutrients to develop and emerge live ex) mammals.
What is altricial parental care?
Altricial- absolutely dependant on continued parental care.
What is precocial parental care?
Precocial- require minimal parental care.
Discuss seasonal breeders
Seasonal anestrus, prevents females from giving birth when survival of the offspring is unlikely. Most give birth in spring. -Partly controlled by circannual clocks to be wary of photoperiod and other env. conditions.
Discuss synchronization and mating behaviour
Env cues, pheromones and other signals serve as synchronizing signals. -Elaborate courtship displays advertise the genetic fitness of the male
What are some secondary sexual characteristics?
-External characteristics, not directly involved with reprod (antlers). to distinguish males form females. -Body configuration, hair distribution, feather colouration and sexual weaponry.
What are the two male reprod functions?
Production of sperm continuously and delivery of sperm to the female.
Simplex: Single uterine body
Duplex: two cervical canals that separate each uterine horn into distinct compartments
Bicornuate: small uterine body and two uterine horns (cornua)
Differenciate between zygote, embryo and fetus
Zygote- before cell division (after fertilization, but before cell division)
Embryo- product of fertilization. ESpecially during early development when tissue differentiation is taking place.
Fetus- features are discernible and connected to mother through placenta for gestation.
In male insects what is the site of spermatogenesis
Sperm tubes in the testes
What are the sex chromosomes of
How is gonadal sex determined?
The absence or presence of a Y chromosome in mammals
What does the SRY gene do?
What happens when Wolffian ducts regress?
Wolffian duct (male ducts) regress due to anti-müllerian hormone--> Female reproductive tract.
Have Mullerian ducts, no testies
Where does spermatogenesis take place in mammals?
The seminiferous tubules
What is Cryptorchidism?
Undescended testes that interfere with spermatogenesis due to temperature.
Where is testosterone secreted?
The connective tissue between the seminiferous tubules
What are the effects of testosterone:
1. reproductive system
2. Sex-specific tissues
3. Other reprod effects
What are the effects of testosterone on:
-Secondary sexual characteristics