Earth and Life Science - Reproduction in Animals

Lesson Objectives

• Identify types of asexual and sexual reproduction in animals.
• Describe different ways representative animals reproduce.
• Understand the importance of reproduction for the continuity of life.

Types of Reproduction

Asexual Reproduction

• Definition: New individuals form from a single parent's cells.
• Common in plants, less common in animals.
• No union of gametes (sperm and egg cells); offspring are similar or identical to the parent.
• Does not alter chromosome number.
• No mate required for reproduction.

Types of Asexual Reproduction

• Binary Fission: Organism divides into two, each growing into a new organism.
  • Example: Amoeba, cyanobacteria, paramecium.
• Budding: New individual grows from the parent and eventually detaches.
  • Example: Hydra, yeast.
• Fragmentation: Parent breaks into pieces, each developing into a new organism.
  • Example: Fungi, worms, sea stars, flatworms, sponges.
• Parthenogenesis: Female offspring develop from unfertilized eggs.
  • Example: Bees, ants, aphids.
• Transverse Fission: Organism divides, with each part regenerating missing parts to become a complete animal.

Sexual Reproduction

• Definition: New organisms form from two organisms using gametes.
• Sperm (male gamete) fuses with egg (female gamete) to form a zygote.
• Results in genetically diverse offspring different from both parents.
• Example organisms: Humans, frogs, fish, cats, dogs.

Methods of Reproduction

Oviparous Animals

• Lay eggs with little or no embryonic development within the parent.

Viviparous Animals

• Bring forth live young developed inside the parent's body.
• Directly give birth to their kind, which grow up and live.

Key Differences Between Asexual and Sexual Reproduction

• Asexual reproduction involves one parent; sexual reproduction involves two parents.
• Asexual reproduction results in offspring genetically similar to the parent; sexual reproduction results in genetically diverse offspring.

Activity and Terminology

• Identify organisms as reproducing asexually (A) or sexually (S).
  • Example: Yeast (A), Rabbit (S).
• Complete terms related to reproductive methods using vowels.
  • Examples: IS2X51L (Asexual), FR1GM2NT1T34N (Fragmentation).

Reflection Questions

• Observe and compare images to identify similarities or differences in reproductive methods.

These notes provide an overview of the main concepts related to animal reproduction covered in this lesson, including the types and methods of both asexual and sexual reproduction.