1. Comparing Life Cycles
4.10C – explore, illustrate, and compare life cycles in living organisms
5.10C – describe the differences between complete and incomplete metamorphosis of insects

2. Vocabulary
Cycle- A series of repeating events that usually lead back to a starting point. Metamorphosis- A physical or structural change (transformation).
This slide contains key vocabulary terms and definitions.

3. Life Cycle Table Species Egg Larva / Nymph Pupa Adult Housefly
8-12 hrs
5 days
4-5 days
2 weeks
Monarch Butterfly
4 days
10 days
2-6 weeks
Ladybug
3-9 months
Using the table you can compare and contrast the life cycles of the housefly, monarch butterfly, and ladybug.

4. Is this an example of complete or incomplete metamorphosis
Is this an example of complete or incomplete metamorphosis? How do you know?
The fly passes through four life stages. The cycle begins with the adult laying the eggs. These stages are egg, larva (maggot), pupa, and adult. The egg stage usually requires 8-10 hours for completion. The larva stage takes about 5 days and the pupa stage usually takes about 4-5 days. Therefore it will take approximately 10 days to develop from the egg stage to adulthood.

5. Is this an example of complete or incomplete metamorphosis
Is this an example of complete or incomplete metamorphosis? How do you know?
The butterfly also goes through four life stages. The cycle begins with the adult laying the eggs. The egg stage is where the primary early development takes place regarding hereditary traits, or characteristics. In the larva stage it is in the form of a caterpillar. This is the primary eating and growth stage for the insect. The pupa is the transformation stage. It is at this stage inside the cocoon that the spectacular transformation takes place. Finally, the butterfly emerges from the pupa as an adult.

6. Is this an example of complete or incomplete metamorphosis
Is this an example of complete or incomplete metamorphosis? How do you know?
The ladybug also goes through four life stages. The cycle begins with the adult lady bug laying tiny, yellow eggs on a leaf. The eggs hatch within 3-4 days. Then, small black larva hatch from the egg. The larva attach to a leaf or stem. The larva skin splits open to expose the pupa that is covered to protect the insect while it continues its metamorphic process. Finally, the ladybug emerges from the pupa. Is this complete or incomplete metamorphosis? Complete – the larva looks nothing like the adult.

7. Is this an example of complete or incomplete metamorphosis
Is this an example of complete or incomplete metamorphosis? How do you know?
Life Cycle of a Cricket
Notice there is no pupa or larva stage in this life cycle – incomplete metamorphosis. Only three stages which include the egg, the nymph (which is a smaller version of the adult), and the adult stage.

8. Tadpole (back legs form)
Life Cycle of a Frog
Eggs
Tadpole
Tadpole (back legs form)
Froglet
Adult Frog
10 days
At 10 days the tadpole leaves the egg.
At 8 weeks the back legs have formed.
At weeks the tail begins to disappear.
It takes about 3 years for the frog to reach adult hood.
(Interpreting diagrams) Discuss with students the life cycle of the frog using the table.

9. 1 5 2 Can you label the steps? 3 4 Eggs Adult Frog Tadpole
Tadpole with legs 3
The frog goes through five life stages. The cycle begins with the adult laying the eggs in water (spawning) (Stage 1). Approximately 7-10 days later the tadpoles hatch from the eggs. At this point the tadpole has poorly developed gills, mouth, and tail (Stage 2). About 6-8 weeks later the back legs form (Stage 3). At about weeks the tail shortens and the legs are more developed (Stage 4). Between weeks the frog will reach adulthood and the process starts again (Stage 5). 4
Froglet

10. Comparing Tadpoles to Frogs
Tadpoles have gills.
They lose their gills and breathe with lungs.
Tadpoles have tails.
They lose their tails when they become frogs.
Tadpoles cannot reproduce.
Frogs can reproduce.
Tadpoles cannot live on land.
Frogs can live on land.
Comparing Tadpoles to Frogs. Tadpoles have gills to survive under water. As frogs, they lose their gills and breathe with lungs. Tadpoles have tails, but they lose their tails when they become frogs. Tadpoles cannot reproduce since they are young and underdeveloped. As frogs, they have the ability to reproduce. Tadpoles cannot live on land, but frogs can.

11. Life Cycle of a Bean Plant
1. Seed is planted
2. Seedling grows roots
4. Plant is fully grown; bean pod begins to grow
3. Plant pushes above the soil; leaves begin to form

12. Check your Understanding
What is the major difference between a complete metamorphosis and an incomplete metamorphosis?
What does this illustration show?
Complete metamorphosis has 4 stages and the hatched insect does not look anything like the adult it will become; incomplete metamorphosis is when the newly hatched insect looks like a smaller version of the adult.
The life cycle of a butterfly – complete metamorphosis

13. 3. Describe the life cycle shown in this illustration.
What type of life cycle is described below?
Egg  nymph  adult
The acorn is the seed that gets planted in the ground. The seed grows into a sapling plant which then becomes the oak tree. The oak tree then drops acorns to the ground and the cycle begins again.
The acorn is the seed that once buried in the ground grows. The seed grows into a sapling plant which then becomes the oak tree.
Incomplete metamorphosis – only 3 stages