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22 Cards in this Set
- Front
- Back
asexual reproduction
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creation of new offspring who’s genetic information comes from a single parent without the fusion of gametes
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Sexual
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creation of offspring by the fusion of haploid gametes to form a zygote (fertilized egg)
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mechanisms of asexual reproduction
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fission, budding, fragmentation, regeneration
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ovum
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unfertilized egg
-large and nonmotile |
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spermatozoon
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male gamete
-small, motile cell |
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fission
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the separation of a parent into two or more individuals of approx. equal size
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budding
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new individuals splitting off from existing ones
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fragmentation
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breaking of the body into several pieces, some or all of which develop into adults
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regeneration
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the regrowth of body parts from pieces of an organism
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advantages of asexual reproduction
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-no competition for mate
-create lots of offspring in little time -advantage in stable environments b/c it ensures successful genotype are produced precisely (clones) |
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parthenogenesis
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process by which the egg develops without being fertilized
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hermaphroditism
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an individual has both male and female reproductive systems
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sequential hermaphrodism
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when an individual reverses its sex during its lifetime
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protogynous
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born female and transitions to male
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protandrous
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born male and transitions to female
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fertilization
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the union of sperm and egg
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external fertilization
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eggs are laid by female and fertilized by male in the environment
Eggs are shed by the female and fertilized by the male in the environment -Almost exclusively in moist habitats -Other Factors for external fertilization include: Courtship Behavior, Temperature, or Length of Day -Temperature and day length may cause the population to release the gametes at once or chemical signals such as Pheromones. |
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internal fertilization
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sperm are deposited in or near the female reproductive tract
-Requires sophisticated reproductive systems Organs that deliver sperm and receptacles for its storage and transport to ripe eggs *Species with internal fertilization usually produce fewer zygotes but provides more parental protection than species with external fertilization -Produces few zygotes; results in greater protection and parental care of young -Types of Protection: eggshells, embryo developing in reproductive tract of female, and parental care -Examples: Birds, reptiles and monotremes have amniotic eggs w/ calcium and protein shells -Marsupials retain embryos for short periods of time before letting it crawl out and develop in the pouch -Placental Mammals develop entirely in the uterus, being nourished by the placenta |
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advantages of sexual reproduction
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genetic variation
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gonads
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the organs that produce gametes in most animals
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spermatheca
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a sac in which sperm is stored for a year or more
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claoca
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opening to the outside from the digestive, excretory, and reproductive trace
-in most non-mammalian vertebrates |