ZOO201 Final Term Past Papers Updated 2022 by Sulman Ali

ZOO201 ANIMAL DIVERSITY INVERTEBRATES FINAL TERM

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FINAL TERM 2022

BY SULMAN ALI

what is trapping

Animal trapping, or simply trapping or gin, is the use of a device to remotely catch an animal. Animals may be trapped for a variety of purposes, including food, the fur trade, hunting, pest control, and wildlife management.

Define Flukes?

The approximately eight thousand species of parasitic flatworms in the class Trematoda (Gr. trematodes, perforated form) are collectively called flukes, which describes their wide, flat shape. Almost all adult flukes are parasites of vertebrates, whereas immature stages may be found in vertebrates or invertebrates, or encysted on plants.

Define Ocelli:

Ocelli are concerned in some way with flight, and insects which are good at flying tend to have well developed ocelli. Ocelli consist of 500 to1,000 receptor cells beneath a single cuticular lens. Ocelli are sensitive to changes in light intensity. Ocelli are simple photoreceptors. They consist of a single lens and several sensory cells.

Acoelomate Examples

Examples of acoelomates are found in the kingdom Animalia and the phylum Platyhelminthes. Commonly known as flatworms, Others are parasitic and often pathogenic organisms that live within other animal organisms. Examples of flatworms include planarians, flukes, and tapeworms. Ribbon worms of the phylum Nemertea have historically been considered to be acoelomates. However, these mainly free-living worms have a specialized cavity called a rhynchocoel that some consider to be a true coelom.

Determinate cleavage:

Cleavage is a process of rapid mitotic cell divisions of the zygote to form number of cells for building up the offspring’s body. It results in developmental fate of cells being set early in embryo development. Cell division in a fertilized or unfertilized egg resulting in daughter cells that are no longer able to produce a complete embryo by themselves.

Write down the body form of sponges?

Zoologist have described three sponge body forms:

1. Asconoid
2. Syconoid
3. Leuconoid

1=The simplest and least common sponge body form is the ascon. Simplest type of canal system found in asconoid sponges. Ascon sponges are vaselike. Ostia are the outer openings of porocytes and lead directly to a chamber called the spongocoal

2=In the sycon body form, the sponge wall appears folded. Water enters a sycon sponge through openings called dermal pores.

3=Leucon sponges have an extensively branched canal system. Water enters the sponge through ostia and moves through branched incurrents canals, which lead to Choanocyte-lined chambers.

Write characteristics of class cestoda:

•  Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes);
•  they are ribbonlike worms as adults, known as tapeworms.
•  Their bodies consist of many similar units, known as proglottids.
•  Species of the other subclass, Cestodaria, are mainly fish parasites.
•  Cestodes have no gut or mouth and absorb nutrients from the host's alimentary tract by their tegument, through which gas exchange also takes place.
•  The tegument also protects the parasite from the host's digestive enzymes and allows it to transfer molecules back to the host.
•  Reproduction: Cestodes are exclusively hermaphrodites, cross-fertilization is the norm. During copulation, the cirri of one individual connect with those of the other through the genital pore and then spermatozoa are exchanged.

Alarm Pheromones:

Alarm pheromones are defined as chemical substances, produced and released by an organism, that warn or alertanother of the same species of impending danger. Its provide the Alarm signals visual or auditory.

Describe the life cycle of insect?

Some insects (like butterflies, but also beetles, flies, and bees) develop by complete metamorphosis with 4 life stages: egg, larva, pupa, and adult.

Describe the Mating behavior of Insects?

•  Most insects have complex mating behaviors for locating and recognizing a potential mate, for positioning a mate for copulation, or for pacifying an aggressive mate.
•  Mating behavior may involve pheromones (moths, order Lepidoptera), visual signals (fireflies, order Coleoptera), and auditory signals (cicadas, order Homoptera; and grasshoppers, crickets, and katydids, order Orthoptera)
•  Once other stimuli have brought the male and female together, tactile stimuli from the antennae and other appendages help position the insects for mating.
•  Mating behavior starts by locating mates. Male and female have different strategies toward copulation and reproduction.
•  After locating mates is courtship; one male and female have encountered each other, they may proceed directly to copulation or may first engage in various rituals, collectively known as courtship.
•  The final ritual is copulation.

Importance of Soil Dwelling Insects

•  Weed Killers: So many insects feed upon unwanted weeds just the same manner they do with the cultivated crops.
•  Scavengers: Insects which feed on dead and decaying matter of plants and animals are called as scavengers.
•  Aeration and turnover of the soil: As decomposers, insects help create top soil, the nutrientrich layer of soil that helps plants grow.
•  Promotion of decay process: In many ecosystems millipedes (Diplopoda) have special importance as decomposers.
•  Role in food chain: Food for other animals: Many insects live on grass and plants for food. food insects but in-turn they become prey to many birds, amphibians, fishes, lizards, and other animals.

Describe the ventilating process in Insects?

Most insects have ventilating mechanisms that move air into and out of the tracheal system.

•  Insects do not breathe through their mouths as we do.
•  The do not have lungs and their blood, which is a watery, yellowish liquid, does not carry oxygen and carbon dioxide around their bodies.
•  Insects have a system of tubes, called tracheae, instead of lungs.
•  These tracheae penetrate right through the insect's body.
•  Air enters the tracheae by pores called spiracles.
•  These spiracles are found on each side of the insect's abdomen. Each segment of the abdomen has a pair of spiracles.
•  As oxygen diffuses from the tracheae to the body tissues, and is not replaced by carbon dioxide, a vacuum is created that draws more air into the spiracles. This process is called passive suction.

Describe the role of Pedicellariae in sea urchin?

•  The pedicellariae of sea urchins have either two or three jaws and connect to the body wall by a relatively long stalk.
•  They clean the body of debris and capture planktonic larvae, which provide an extra source of food.
•  Pedicellariae of some sea urchins contain venom sacs and are grooved or hollow to inject venom into a predator, such as a sea star.
•  Each pedicellariae is an effector organ with its own set of muscles, neuropils, and sensory receptors and is therefore capable of reflex responses to the environment.

Define pinacocytes?

Thin, flat cells, called pinacocytes, line the outer surface of a sponge. Pinacocytes may be mildly contractile and their contraction may change the shape of some sponges. In a number of sponges, some pinacocytes are specialized into tube like, contractile pinacocytes, which can regulate water circulation.

Describe the life cycle of Spider?

The spider life cycle has three stages of development: egg, spiderling and adult. Depending on the species, spiders can lay up to 3,000 eggs, usually in one or more silk sacs. In some spider species, the female dies after laying the eggs. Others carry the egg sac in the chelicerae or attach it to their spinnerets.

Describe the Nervous System of Star Fish?

The nervous system of sea stars consists of a nerve ring that encircles the mouth and radial nerves that extend into each arm. • Radial nerves lie within the ambulacral groove, just oral to the radial canal of the water-vascular system and the radial strands of the hemal system. • Radial nerves coordinate the functions of tube feet. • Other nervous elements are in the form of a nerve net associated with the body wall. • The nervous system of the starfish is very simple, there is no brain and there are not even any ganglia to coordinate movement.

Which are soil dwelling Insects?

Soil-dwelling insects play important roles in aeration, drainage, and turnover of soil, and they Promote decay processes. Other insects serve important roles in food webs. • Soil-dwelling insects are hidden in the soil and hard to detect until the sudden appearance of damage.

Hemimetabolous:

In incomplete metamorphosis, only some parts of the animal’s body change during metamorphosis. Animals that only partially change their bodies as they mature are called “hemimetabolous”