This document discusses several model organisms used in research: - The fruit fly Drosophila melanogaster and nematode Caenorhabditis elegans are widely used as they are inexpensive, easy to grow, and have short lifecycles. Their genetics are also well understood. - Sheep are used as a model for respiratory research due to anatomical similarities to humans. - Mice strains like C57BL/6 and BALB/c are commonly used. Zebrafish and medaka fish are used for developmental and genetic studies due to their optical transparency and short lifecycles. - Rats like the Sprague Dawley are also used as models in research.

11. Drosophila melanogaster
• The fruit fly (Drosophila melanogaster) is
one of the most studied organisms in the
animal kingdom.
• Drosophila, coupled with similarities in
development and behavior, the fruit fly has
served as a unique and sensitive model for
the study of human genetics and disease
Caenorhabditis elegans
• These small worms are highly prolific
reproducers with a short generation time,
easily grown under laboratory conditions,
and inexpensive to care for.
• Additionally, C. elegans is anatomically
simple and has a fully mapped nervous
system.
• It can serve as a model of both forward and
reverse genetics, with mutants, transgenics,
and knockouts easily created; and worms
that express GFP enable in vivo observation
of cellular and metabolic processes

12. Sheep
The anatomy and physiology of the sheep respiratory system is more similar to that of humans than rodents,
and has been proposed as a good model for vaccines, asthma pathogenesis and inhalation treatments.
Furthermore, it is a large animal (30–90 kg, according to sex and race) with well-studied anatomy and
physiology, is easy to cannulate, and provides ease in taking frequent and/or large samples.

16. Types of mice

18. Aquatic

21. ❖ Although developmental biology research of fish is primarily conducted
using the zebrafish, a small tropical fish or blowfish because of their short
generation time, the medaka is also interesting and unique for its smaller
genome size and its transparency, making their organs visible.
❖
The medaka genome project has gotten underway, and now, we can deal
with genetic variants in the pure strain. Therefore, investigations can be
made into the relation-ship among DNA, shape, and ecology.
❖
Medaka are omnivores and metabolize sugars and lipids in a manner
analogous to that of mammals.
MEDAKA FISH

25. Types of Rat

31. SPRAGUE DAWLEY
WISTAR RAT

33. Life cycle of Zebra Fish

35. Zygote development

36. Blastula Stage

37. Embryonic
Development-Gastrulation Stage

38. SEGMENTATION PERIOD

39. Pharyngula Period

40. Hatching Period

41. HYDRA -AQUATIC ANIMAL

47. LIFE CYCLE OF DROSOPHILA

49. LIFE CYCLE OF C. elegans

53. Genetic Information of Drosophila