Chapter 46: Animal Reproduction Flashcards
Sexual reproduction
production of an offspring by fusion of a male haploid gamete (sperm) and female haploid gamete (egg) to form a diploid zygote; typically by meiosis
Asexual reproduction
production of an offspring without the fusion of egg and sperm and whose genes all come from one parent; typically by mitosis
Gamete
(typically) haploid cell involved in sexual reproduction (sperm, egg)
Zygote
a fertilized egg, (typically) diploid cell produced by fusion of sperm and egg
Fertilization
process of uniting haploid gametes to produce a diploid cell
Parthenogenesis
a form of asexual reproduction in which females produce off-spring that develop from unfertilized eggs
Hermaphrodite
an individual that functions as both male and female in sexual reproduction by producing both sperm and eggs
Conditions that are advantageous for asexual organisms
Stable environment and dispersal
Advantages of internal fertilization
ensuring paternity, less risk of desiccation of sperm/eggs, species-specific modifications that ensure mating success
External fertilization
Fertilization outside the female reproductive tract, females and males both release gametes into the environment where gametes unite
Internal fertilization
Fertilization inside the female reproductive tract, male deposits sperm in the female reproductive tract where gametes unite
Typically, animals that fertilize eggs internally produce _____ eggs than those with external fertilization, but a _____ number of zygotes survive
fewer; higher
Mammalian reproduction
sexual reproduction with internal fertilization
Penis
passageway for both urine and semen (sperm plus seminal fluid)
Testes
produce sperm and hormones
Seminal vesicles
nourish the sperm with a fructose-rich fluid; secrete ~60% of the total ejaculate volume