Asexual and Sexual Reproduction
p. 132-133, 135
Asexual Reproduction
• The production of individuals without ____________________________ (sex cells).
• Offspring are genetically identical to the parent and called _____________________________.
• Occurs in:
? ________________________________________________________________________
? ________________________________________________________________________
? ________________________________________________________________________
Fission
• _________________________ fission
? The body of the parent divides by _____________________ into 2 approximately equal parts
? Each part grows into an individual similar to the _________________________
? Ex: _____________________________________________________________________
• _________________________ fission
? The ________________________ divides repeatedly before division of the cytoplasm
? Produces many daughter cells _______________________________________
? Ex: spore formation
___________________________________
• ___________________________ division of an organism
• New individual arises as an __________________________________ (bud) of its parent
• Develops organs like those of the parent
• Detaches itself
• Ex: ______________________________________
Gemmulation
• Formation of a new individual from an _______________________________ of cells surrounded by a resistant capsule (gemmule)
• Gemmules often form in the ____________________, survive the _______________________ in the dried or frozen body of the parent, and become active and grow in the _______________
• Ex: __________________________
Fragmentation
• _________________________________________ animal breaks into 2 or more parts
• Each fragment is capable of becoming a ______________________________________________
• Ex: ______________________________
Sexual Reproduction
• Production of individuals from gametes
• Bisexual (biparental) reproduction
? involves 2 separate parents
• Hermaphroditism
• Parthenogenesis
Bisexual Reproducion
• Production of offspring formed by the union of gametes from 2 genetically __________________________ parents
• Offspring have a _________________________________________ genotype
• Parents are characteristically of different __________________________
? _______________________
? _______________________
• Distinctions between male and female are based on the _____________________________ and _________________________ of the gametes they produce.
• Ovum (____________________)
? Produced by _______________________________
? Large (because of stored __________________________ to sustain early development)
? ___________________________________________
? Produced in relatively __________________________________ #’s
• Spermatozoon (_____________________)
? Produced by _________________________________
? __________________________________
? __________________________________
? Produced in ______________________________________ #’s
• Meisois
? Gamete-producing nuclear division
? Chromosomes split _____________________
? Cell divides _______________________
? End result – ______________________________________________________________
___________________________________________________________________________
• Fertilization
? 2 haploid gametes are combined to restore the normal (diploid) chromosomal # of the species
? Fertilized egg is called the ___________________________
• Genetic ______________________________, due to meiosis and fertilization, is the great strength of sexual reproduction.
? Provides ___________________________ genetic combinations
Sex Organs
• Primary Sex Organs
? _____________________________
• Produce _____________________________ (gametes)
• Testis – produce ______________________
• Ovary – produce ______________________
• Accessory sex organs
? ___________________________ and ____________________________ germ cells
Disadvantages of Sexual Reproduction
• ______________________________________________________________________________
• ______________________________________________________________________________
• ______________________________________________________________________________
Advantages to Sexual Reproduction
• ______________________________________________________________________________
? Produces novel genotypes that ______________________________________________
____________________________________________________ may survive and reproduce
• ______________________________________________________________________________
? Allows a species to _________________________ to changing environments