Developmental Biology - I Lab Experiments

The sperm is elongated (800 microns), with a head (pear-shaped) and a filament. The egg is tiny, creamy, and flaccid, with a yolk-rich cytoplasm and a female pronucleus.

A mixture of methylene blue and eosin dyes used to stain biological samples, highlighting different cellular components.

The head of the sperm, containing the nucleus, stains purple in a Giemsa-stained sample.

Samples are fixed in alcohol, stained with a Giemsa solution, and then destained/cleared/mounted. Requirements include alcohol-fixed smears, Giemsa stain, distilled buffered water (pH 7.2), alcohol grades, and acetone.

A small, unsegmented nematode worm used as a model organism in developmental and molecular biology research.

An adult hermaphrodite C. elegans has precisely 959 somatic cells, whose lineage is precisely known

An organism that is commonly studied to understand basic biological concepts which can then be applied to more complex organisms

Body cells in any organism.

The larva between molts.

Stage where larva transforms into adult, body hardens and shortens.

Dormant embryonic tissues that develop into adult structures.

Breakdown of larval tissues to create adult structures; material and energy source.

Size varies by species; males and females may differ.

Differences in size or appearance between males and females.

Specialized glands on male beetle legs, absent in females; used for identification.

Consists of egg, larva, pupa, and adult stages.

Ovoid and bright white

Lasts 3.5-5 days in ideal lab conditions

Worm-like and yellowish

2-3 weeks for T. castaneum and T. confusum

Light colored, white or yellowish

Gin traps on abdominal segments for defense

Females have larger genital papillae

7-11 months (T. castaneum and T. confusum)

A biological process of transformation where an organism undergoes significant changes in its physical form and structure, often involving distinct stages of development, as seen in insects like butterflies.

The stages are egg, larva (caterpillar), pupa (chrysalis), and adult butterfly.

A hardened case secreted by the larva of some insects, like flies, where the pupa develops inside.

Caterpillars mainly feed on plants, which provide them with the necessary nutrients and energy for growth.

Butterfly pupae, also called chrysalises, are often exposed, while moth pupae are typically protected inside a silken cocoon.

Appendages with two branches, an exopod and an endopod, found in some crustaceans.

A larval stage in some crustaceans, characterized by a segmented body and biramous appendages.

A larval stage in crabs, with a broad, crab-like body and uniramous thoracic appendages.

A modified zoea larva found in Mantis shrimp, characterized by a slender body and a large raptorial claw.

The idea that the development of an organism (ontogeny) reflects its evolutionary history (phylogeny).

A primitive larval form found in many crustaceans, with three pairs of appendages.

Larvae are important for understanding crustacean evolution, identifying relationships between species, and aiding in species distribution.

The transformation of an immature larval form into a sexually mature adult.

A larval stage in sponge development, characterized by an ovoid shape with an anterior half of small flagellated cells and a posterior half of larger, non-flagellated cells. It develops from a stomoblastula by inversion and leads a free-swimming existence before settling and developing into a young sponge.

The flattened, ciliated, bilaterally symmetric, free-swimming larval stage of various cnidarian species and some ctenophores. It can develop from a fertilized egg of a medusa (Scyphozoans and Hydrozoans) or from a polyp (Anthozoans).

A parasitic larval stage in the life cycle of some trematodes (flukes), particularly the liver fluke. It is oval-shaped, about 0.25 to 0.35 mm in length, and gives rise to cercaria larvae.

The free-living larval stage of a liver fluke, characterized by a flat, oval body and a long, muscular tail. It is the fourth larval stage in the life cycle, produced by the redia larva.

A tiny opening on the surface of a sponge larva (amphiblastula).

A specialized cell in sponges responsible for secreting spicules.

The hard, supportive structures in sponges made of calcium carbonate or silica.

Amoebocytes are found inside the central cavity of the amphiblastula larva. They are responsible for various functions, including the movement of nutrients and waste within the larva.