Lecture 19 Flashcards
How do Metazoans reproduce?
Sexually
What tends to be the pattern of movement for Metazoa s throughout their lifetime?
They tend to have motile juveniles and sessile adults .
What are the required components of sexual reproduction?
Meiosis (2n—->1n) and Gamete Fusion (1n—->2n)
What types of cells are gametes?
Sexual cells
In terms of size, how can the gametes be classified?
Anisogamy (different sized) and Isogamy (same sized)
In what organisms do we tend to see more isogamy?
Protists.
Through what technique do animals asexually reproduce?
Through mitosis (2n —-> 2n)
Asexual reproduction is ancestral for _____.
Eukaryotes.
Is asexual reproduction more common or sexual reproduction?
Asexual reproduction.
What are the types of Asexual Reproduction?
Budding-Fragmentation-Fission
Define Budding
Deliberate, plant-like growth.
What is the main difference between fragmentation and fission?
Fragmentation is sometimes accidental but fission is always on purpose.
What are the main differences between sexual reproduction and asexual reproduction?
Sexual reproduction requires 2 individuals (gametes) and each individual only passes on half of its genome; asexual reproduction requires one individual and each individual passes on its whole genome.
Why did sexual reproduction evolve?
Genetic Recombination.
What are the main benefits of doing sexual reproduction?
Increase in genetic diversity and compensation for bad mutations.
Define Hermaphrodites
Organisms that have male and female gametes.
What are the different types of hermaphrodites?
Simultaneous and Sequential.
Define Simultaneous Hermaphrodites
They have testes and ovaries at the same time; sperm and egg production at the same time.
Define Sequential Hermaphrodites
They start out as one sex and transition to another.
What are all the differences between sexual and asexual reproduction?
Sexual reproduction slower, needs a partner, meiosis based, and encourages high genetic diversity and aids local adaptation; asexual reproduction is faster, needs no partner, mitosis based, and is highly effective in stable environments.
Reproduction is _____; what does this mean?
Costly; it means that animals reproduce only when resources are plentiful.
What are the different types of fertilization?
Internal and External
What are some things to note about external fertilization?
Spawning is another name for it and it requires water.
What are some things to note about internal fertilization?
Spermatophores are included and terrestrial adaptations occur.
