Chapter 18 Flashcards
Define and give examples of Parthenogenesis, Budding, Fragmentation, and Fission.
Fission: organisms appear to split itself into two parts and, if necessary, regenerate the missing parts of each new organism. Ex. Planarians and Sea anemones (Cnidaria)
Budding: asexual repro that results from the outgrowth of a part of the body leading to a separation of the “bud” from the original organism and the formation of two individuals, one smaller than the other. Ex. Hydras
Fragmentation: the breaking of an individual into parts followed by regeneration. Ex sponges
Parthenogenesis: Egg developes into an individual without being fertilized. Ex. invertebrates (water fleas, ants)
Define the internal fertilization concepts or Viviparity, Ovoviviparity, and Oviparity.
Oviparity: fertilized eggs are laid outside the female’s body and develope there recieving nourishment from the yolk that is part of the egg.
Viviparity: the young are born alive. They obtaine their nourishment from the female born in verying states of maturity.
Ovoviviparity: fertilized eggs are retained in the female, and the nourishment from the egg’s yolk. They either stay inside of the female or she lays the eggs right before they hatch
What are the three germ layers and what do they give rise to?
Ectoderm: gives rise to the nervous sytem and epidermis
Mesoderm: gives rise to the body’s muscle cells and connective tissues
Endoderm: gives rise to the gut and many internal organs
Define eacch of the following procedures: Vasectomy and Tubectomy
Vasectomy: a section of the vas deferens is removed, preventing sperm from
being passed out of the body during ejaculation and preventing fertilization.
Tubectomy: in that the oviducts
are severed and sealed, preventing sperm from
reaching the egg
What is gametogenesis?
The production of sperm and eggs
What are the functions of the hormone testosterone?
Stimulating spermatogenesis and development of secondary sexual characteristics in genetic males
What are the characteristic of each trimester and labor? In which trimester is exposure to toxins more dangerous?
1st: Embryo merges with the endometrium and placenta form
2nd: Fetus becomes active and the mother usually feels the first movements
3rd: the most rapid growth during pregnancy as all organ systems continue to grow and develop
Labor: muscular contractions to expel fetus and placenta from the uterus
What happens to primitive gonads when testosterone is absent during development?
Primitive gonads develop into ovaries
What are hermaphrodites?
Animals that have both male and female reproductive parts
What does the ovarian cycle govern?
The preparation of endocrine tissues and the release of eggs
What does the menstrual cycle govern?
The preparation and maintenance of the uterine lining
