• a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
• a solid ball of cells resulting from division of a fertilized ovum, and from which a blastula is
• a mammalian blastula in which some differentiation of cells has occurred.
• an unborn or unhatched offspring in the process of development.
• an unborn offspring of a mammal, in particular an unborn human baby more than eight
weeks after conception.
• a baby from birth to four week
The Amphibian Reproductive Cycle
A jelly-like eggs are laid in
water, hatch into legless
tadpoles with gills, the
tadpoles grow one set of
legs, then they
metamorphose into an airbreathing froglet with a tail.
Froglets lose their tails as
they grow into adult frogs. A
lot of amphibians lay their
eggs out of water, finding
interesting ways to keep
their eggs and tadpoles wet.
EGG: unborn stage.
LARVA: the active immature form of an insect, esp. one
that differs greatly from the adult and forms the stage
between egg and pupa, e.g., a caterpillar or grub.
PUPA: an insect in its inactive immature form between larva
and adult, e.g., a chrysalis.
ADULT: final, breeding stage (they usually grow wings)
• Asexual reproduction is natural “cloning.”
Parts of the plant, such as leaves or stems,
produce roots and become an independent
• Sexual reproduction requires fusion of male
cells in the pollen grain with female cells in
Terms to know:
• Haploid: having a single set of chromosomes
in each cell.
• Diploid: having two sets of chromosomes in
• Mitosis: cell division, which produces two
genetically identical cells.
• Meiosis: reduction division, which produces
four haploid reproductive cells.
Plant Life Cycle
Alternation of Generations
• Plants have a double life cycle with two
– Sporophyte: diploid, produce haploid spores by
– Gametophyte: haploid, produce gametes by
Mosses, ferns, and related plants have motile,
• Flowers are complete if they have all
parts, and perfect if they have both
male and female parts.
• Grass flowers: incomplete, usually
imperfect (separate male and female
• A tulip is complete (though the sepals
are the same color as the petals) and