Embryology: Reproduction Methods Quiz

Embryology

• Embryology is the study of the early development of living organisms
• All animals and plants can reproduce new individuals to ensure the survival of their kind
• Reproduction can be asexual or sexual

Asexual Reproduction

• Involves a single organism splitting, budding, or fragmenting to create two or more individuals

Types of Asexual Reproduction

• Splitting: The organism splits into two individuals (e.g., Paramecium)
• Budding: The organism produces a small bud that grows on the parent's body, then breaks off to become a new individual (e.g., Hydra)
• Fragmentation: The organism breaks into fragments, which grow into new organisms, sometimes forming a colony (e.g., yeast)

Sexual Reproduction

• Involves the fusion of two gametes (a male gamete, sperm and a female gamete, egg) to form a zygote (fertilized egg)
• The chromosomes of the sperm and egg combine to form the 2n chromosomes of the zygote
• The zygote undergoes embryonic development and cell division, resulting in a large number of somatic cells containing diploid chromosomes (2n), forming the embryo
• Gametogenesis is the process by which gametes (sperm and egg) are formed, containing haploid (n) chromosomes

Gametogenesis

• The process by which gametes (sperm and egg) are produced
• Involves the reduction of chromosome number to haploid sets in resulting gametes

Spermatogenesis

• The process of sperm production in the testicles
• Three phases:
  • Multiplication: Primordial germ cells undergo mitotic divisions creating spermatogonia
  • Growth: Spermatogonia grow to form primary spermatocytes with 2n chromosomes
  • Maturation: Primary spermatocytes undergo meiosis I and II, resulting in four spermatids with n chromosomes. Spermatids mature into spermatozoa (sperm) through a process called metamorphosis

Oogenesis

• The production of mature ova (egg cells) in the ovaries
• Ovaries contain primordial germ cells that undergo meiosis to form ova

Structure of a Spermatozoon (Sperm Cell)

• Includes an acrosome, nucleus, basal body, mitochondria, axoneme (tail)

Types of Sperm

• Various shapes and structures exist among animal species