ZOO201 Midterm Guess Paper Updated 2022 by Badsha Ali

ZOO201 Complete 100% guess paper · by Badsha Ali · 1= write down 3 Characteristics of Phylum Arthropods

•  They have paired jointed appendages.
•  Ecdysis or molting takes place during growth.
•  They have ventral nervous system.
•  Coelom reduced to cavities. These cavities are reduced to gonads and sometimes excretory organs.

2=Short note on rotifers

•  They are abundant in most fresh water habitats.
•  A few species (less than 10%) are marine.
•  Some have beautiful colors, although most are transparent, and some have odd and bizarre shapes.
•  They are triploblastic, bilateral, unsegmented, and pseudo coelomate.

3=Excretory system

The systems that excrete wastes from the body. For example, the system of organs that regulates the amount of water in the body and filters and eliminates from the blood the wastes produced by metabolism.

4=Excretory system in earthworm:

Excretion in earthworm is performed by long, thin and coiled tubules known as nephridia. It is found in all segment except first two. They are the small microscopic coiled tube with the thin wall which is glandular and vascular. According to location, nephridia are of three types they are:

•  Septal nephridia
•  Pharyngeal nephridia
•  Integumentary nephridia

5=Function of pellicles in protozoans:

Most protozoans are enclosed by a skeletal structure known as the pellicle consisting of the plasma membrane and underlying cytoskeleton (with additional membranes, microtubules, microfilaments, or plates of cellulose or protein). The pellicle maintains the shape of the cell.

6=Difference between phylum arthropod and annelids:

7=Typhlosole:

A longitudinal fold of the intestinal wall in certain invertebrates that increases the absorptive and digestive surface area of the intestine. Typhlosoles occur in bivalve mollusks, lampreys and some annelids and echinoderms.

8=Dioecious and monoecious:

The plants or organisms that have both female and male sexual organs or flowers on the same plant are called Monoecious plants. Examples, banana, Squash, Earthworms, slugs, jellyfish and planarians

The plants or organisms that have separate female and male sexual organs or flowers are called dioecious plants. Examples, holly plants, ginkgo tree, Mammals, birds, reptiles and insects.

9=Tubular system in nematodes:

Nematodes are tubular in shape and are considered pseudo coelomates because of they do not possess a true coelom. Nematodes do not have a well-developed excretory system, but do have a complete digestive system. Nematodes possess the ability to shed their exoskeleton in order to grow, a process called ecdysis.

10=Evolutionary adaptations process of parasitic nematodes:

The main evolutionary innovation of nematodes is their complete digestive system, which contains two openings (a mouth and anus).

Since the ingestion and the defecation processes can occur at different extremities of the digestive tube, organisms with a complete digestive system have the advantage of being able to

Annelids

Arthropods

From head to tail, metameric segmentation is observed where the body is segmented. The body is not completely segmented due to incomplete metameric segmentation.

Annelids' circulatory systems are closed. Arthropods have a free-flowing circulatory system.

The body is divided into several segments that are all the same. The body is divided into several specialized sections.

Annelids do not have appendages. Arthropods have appendages that are joined together.

They are known as segmented worms. Animals with jointed legs are what they are called.

The true body cavity they have is called a coelom. The presence of a blood-filled body cavity, known as a 'hemocoel.'

The majority of annelids are hermaphrodites. For example, Earthworm. They are divided into two sexes. For example, Crab. ingest new food while the residue of already eaten food is still inside the body and has not yet been eliminated.

1. They have high reproductive potential.
2. Their life cycles increase the likelihood of transmission from one host to another.
3. They develop an enzyme resistant cuticle, resistant eggs, and encysted larvae.

11=Difference between monophyletic and paraphyletic and polyphyletic:

Monophyletic group is a group of organisms that includes an ancestral species and its entire descendent species. Monophyleyic group is also known as a clade. A clade is a natural kind of a group that is very important in phylogenetic classification. Monophyletic groups are created based on the shared derived characteristics. Hence, monophyletic group can visualize relationships among the organisms in a phylogenetic tree.

Paraphylatic group is a group of organisms that consist of an ancestral species and some of its descendant species. Not all the descendent species are included in this group. Paraphyletic group is nearly monophyletic. The paraphyletic group is created based on the symplesiomorphy. Some well known paraphyletic taxa are Pisces and Reptilia.

A polyphyletic taxon is a group of organisms that lack a common ancestor. The polyphyletic group consists of unrelated organisms who are descended from more than one ancestor. It is kind of an unnatural group of organisms. Normally when a polyphyletic taxon is found, it is reclassified since it is a totally unnatural assemblage.

12=Spongocoel:

The simplest and least common sponge body form is the ascon. Ascon sponges are vase like. Ostia are the outer openings of porocytes and lead directly to a chamber called the spongocoel.

13=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.

Determinate cleavage: It results in developmental fate of cells being set early in embryo development.

14=Circulatory system of cephalopods:

Cephalopods are the only molluscs with a closed circulatory system. Coleoids have two gill hearts (also known as branchial hearts) that move blood through the capillaries of the gills. A single systemic heart then pumps the oxygenated blood through the rest of the body.