Reproduction & Development Flashcards
Asexual Reproduction
Produce offspring genetically identical to parent
Advantageous when environmental conditions are stable
Fission
Asexual Reproduction
The separation of an organism into 2 new cells
Budding
Asexual Reproduction
Involves splitting off of new individuals from existing ones
Fragmentation
Asexual Reproduction
When single parent breaks into parts that regenerate into new individuals
Parthenogenesis
Asexual Reproduction
Involves development of egg without fertilization, result adult = haploid
Testes
Make gonads; site of sperm formation
Vas Deferens
The duct that carries sperm during ejaculation from epididymus to penis
Prostate Gland
Secrete semen directly into urethra
Scrotum
Holds testes; the colder the temperature there enables sperm to survive
Urethra
Tube that carries semen & urine
Ovary
Meiosis & where secondary oocyte forms prior to birth
Oviduct/Fallopian Tube
Where fertilization occurs; after ovulation, egg moves through oviduct to uterus
Uterus
Where embryo develops
Vagina
Birth canal; baby passes through cervix into it
Cervix
Mouth of uterus
Endometrium
Lining of uterus
Follicular Phase
Follicles grow & secrete increasing amounts of estrogens in response to FSH from anterior pituitary
Spermatogenesis
Process of sperm production, continuous process - begins as LH induces testes to produce testosterone - together FSH & testosterone stimulate sperm production in testes
Oogenesis
Production of ova by meiotic cell division
Cleavage Furrow
Embryonic Development
Rapid mitotic cell division of zygote that begins immediately after fertilization, produce blastula
Gastrulation
Embryonic Development
Process by which blastula develops into a gastrula
Organogenesis
Embryonic Development
Process by which cells continue to differentiate, producing organs from the 3 embryonic germ layers
Chorion
Bird Embryo
Under shell, allows for diffusion of respiratory gases between outside environment & inside of cell
Yolk Sac
Bird Embryo
Encloses the yolk, the food for the growing embryo
Amnion
Bird Embryo
Encloses the embryo in protective amniotic fluid
Allantois
Bird Embryo
Like placenta in mammals
Is the conduit for respiratory gases to & from embryo, where nitrogenous waste uric acid accumulates until chick hatches
Reproductive Cycles
Controlled by a combination of hormonal & environmental cues
Sexual Reproduction
Offers increased variation among offspring & the possibility of greater reproductive success in a changing environment
Hermaphrodites
Can mate with any animal of their species
Both animals act as male & female, and both donate & receive sperm
Advantages of Asexual Reproduction
Enables reproduction without a mate
Creates numerous offspring quickly
No expenditure of energy
Advantages of Sexual Reproduction
Variation
Offspring is product of both parents, may be better to survive than either
Semen
Nutritive fluid that carries sperm
Menstrual Cycle
Series of changes in the ovary & uterus that is controlled by the interaction of hormones
Ovulation
Secondary oocyte ruptures out of ovaries in response to increase in LH from anterior pituitary
Follicles
Several tiny cavities in ovaries
Luteal Phase
After ovulation
Corpus luteum forms & secretes estrogen & progesterone that thicken the endometrium
Menstruation
If implantation of embryo does not occur
Buildup of lining of uterus breaks down & is shed
Corpus Luteum
Cavity the follicle left behind
Blastula
Fluid-filled ball of cells produced at the end of cleavage
Blastomeres
Individual cells of blastula
Blastocoel
Fluid-filled center
Gastrula
Three-layered embryo
Consist of ectoderm, endoderm & mesoderm that will develop into parts of the adult animal
Extraembryonic Membrane
Structures that arise outside the bird embryo
