Draw a well labelled diagram of the internal anatomy of a Lancelets. Draw a well labelled diagram of the internal anatomy of a larva tunicate along with 6 characteristics feature of the organism; habitats; feeding etc. Well labelled diagram of the adult tunicate.

A well-labelled diagram of a lancelet (e.g., Branchiostoma) should show its elongated, fish-like body. Key internal structures include the notochord, dorsal hollow nerve cord, pharyngeal slits, endostyle, gill bars, atrium, atrial pore, intestine, hepatic cecum, and anus.

• Notochord: Provides skeletal support throughout life.
• Dorsal hollow nerve cord: Forms the central nervous system.
• Pharyngeal slits: Used for filter feeding and respiration.
• Endostyle: Produces mucus to trap food particles and is homologous to the thyroid gland.
• Gill bars: Support the pharyngeal slits and contain blood vessels for gas exchange.
• Atrium: A body cavity surrounding the pharynx, collecting filtered water.
• Atrial pore: Opening through which water exits the atrium.
• Intestine: Digests food.
• Hepatic cecum: A blind-ended diverticulum involved in digestion and absorption.
• Anus: Expels undigested waste.

A tunicate larva (e.g., ascidian tadpole larva) is free-swimming and resembles a tadpole. Essential labels include the notochord (in the tail), dorsal hollow nerve cord (in the tail and anterior body), pharynx with gill slits, adhesive papillae, otolith (statocyst), and ocellus (photoreceptor).

• Notochord: Provides support for the tail, aiding in swimming.
• Dorsal hollow nerve cord: Controls movement and sensory functions.
• Pharynx with gill slits: Involved in filter feeding and respiration.
• Adhesive papillae: Used for attachment to a substrate during metamorphosis.
• Otolith: A gravity-sensing organ, helping with orientation.
• Ocellus: A light-sensing organ, aiding in navigation.

Here are six characteristics:

1. Feature: Possesses all four chordate characteristics (notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail).
2. Habitat: Marine, free-swimming in the water column.
3. Feeding: Non-feeding; it is a dispersal stage.
4. Locomotion: Propels itself using its muscular tail.
5. Sensory organs: Has a light-sensitive ocellus and a gravity-sensing otolith.
6. Metamorphosis: Undergoes dramatic metamorphosis to an sessile adult form.

An adult tunicate (e.g., sea squirt) is sessile and sac-like. Important labels include the incurrent siphon, excurrent siphon, pharynx (branchial basket) with numerous stigmata (gill slits), endostyle, atrium, stomach, intestine, gonads, and heart.

• Incurrent siphon: Draws water into the body for feeding and respiration.
• Excurrent siphon: Expels filtered water and waste products.
• Pharynx (branchial basket) with stigmata: Filters food particles from water and facilitates gas exchange.
• Endostyle: Produces mucus to trap food particles in the pharynx.
• Atrium: A large cavity surrounding the pharynx, collecting filtered water.
• Stomach: Digests food particles.
• Intestine: Absorbs nutrients and forms fecal pellets.
• Gonads: Reproductive organs, producing gametes.
• Heart: Circulates blood in an open circulatory system.