Flashcards in Chapter 6.2 Deck (14):
How does nature ensure sexual reproduction to occur within the same species?
Sperm and egg cells have unique proteins and sugars on their surface.
The fertilization of an egg will occur only if the right sugar meets the right protein of the same species.
What are the 3 stages of reproduction?
mating, fertilization, development
What is the difference between external fertilization and internal fertilization?
External: Sperm and egg cell unites outside the bodies of the parents
Internal: Sperm is deposited inside the female's body where it meets the egg cell
What type of organisms use external fertilization?
Aquatic animals and plants.
ex: sea urchins, fish, mosses
What are the advantages of external fertilization?
Little energy is required to find a mate, large numbers of offspring can be produced at one time
What are the disadvantages of external fertilization?
Zygotes are unprotected and often preyed upon. Parents do not care for offspring so few survive adulthood
What type of organisms use internal fertilization?
mostly land animals and plants
ex: humans, snakes, flowering plants
What are the advantages of internal fertilization?
More offspring survive because of embryo protection and parental care
What are the disadvantages of internal fertilization?
Requires more energy to find a mate and results in fewer zygotes produced
What type of fertilization is pollination
What happens during pollination?
Male gametes are transferred from the male reproductive system (stomen) to the female reproductive part of the plant (pistil)
Pollen grains carry the sperm cells in a protective case to the ovaries
What are other methods of pollination?
Some plants that do not attract pollinators release their pollen into the air.
Seeds or cones are carried by the wind or birds.
What are the advantages of sexual reproduction? (4)
1. Very little energy required to find a mate (external)
2. Greater numbers of offspring can repopulate an area after a disaster (external)
3. More protection is given to the embryo and more parental care is given to offspring (internal)
4. Offspring are genetically different from their parents so the may survive new diseases or other threats that appear in a population*