MCQ : Diversity In Living Organisms - 1 - Class 9 MCQ

Those organisms which freely interbreed are known as species. And group of species or the freely interbreeding organism constitutes Genus.

Member of Porifera: Spongilla
Porifera is a phylum of animals that includes sponges. Among the various species of sponges, Spongilla is a commonly known member of the Porifera phylum. Here are some key details about Spongilla:
- Spongilla:
- Spongilla is a freshwater sponge that belongs to the class Demospongiae within the phylum Porifera.
- It is commonly found in freshwater habitats such as lakes, ponds, and slow-moving streams.
- Spongilla has a porous body structure with numerous canals and chambers that allow water to flow through them.
- It obtains its nutrition by filtering organic particles and microscopic organisms from the water it inhabits.
- Spongilla plays an important role in freshwater ecosystems as a filter-feeder, contributing to the overall water quality.
- It reproduces both sexually and asexually, with the ability to regenerate from fragments or form gemmules for survival during unfavorable conditions.
- Spongilla can vary in color, ranging from green, brown, or grey, depending on the species and environmental factors.
Therefore, Spongilla is a member of Porifera and represents the diversity of sponges within this phylum.

Answer:
The correct answer is D: community.
A community is a group of different species that live and interact with each other in a specific ecosystem. In this case, the forest ecosystem consists of plants, animals, and protists, all of which interact and depend on each other for survival.
Here is a detailed explanation of why D is the correct answer:
1. Definition of a community:
- A community refers to all the living organisms in a particular area that interact with each other.
- It includes plants, animals, and other organisms such as protists.
2. Plants, animals, and protists in a forest:
- Forests are home to a wide variety of plants, animals, and protists.
- Plants include trees, shrubs, and various types of vegetation.
- Animals can range from large mammals to insects and birds.
- Protists are microscopic organisms such as algae and fungi.
3. Interactions within the forest community:
- In a forest, plants provide oxygen, shelter, and food sources for animals and protists.
- Animals, in turn, help disperse seeds, pollinate flowers, and control populations of other organisms.
- Protists play important roles in nutrient cycling, decomposition, and symbiotic relationships with other organisms.
4. Dependence and interconnections:
- All organisms in the forest community depend on each other for survival.
- For example, animals rely on plants for food and shelter, while plants rely on animals for pollination and seed dispersal.
- Protists contribute to the overall balance and functioning of the ecosystem.
5. Importance of studying forest communities:
- Understanding the interactions and relationships within a forest community is crucial for conservation and management.
- By studying the community, scientists can better understand the effects of disturbances, such as deforestation or invasive species, on the ecosystem as a whole.
- Conservation efforts can be targeted towards preserving biodiversity and maintaining the health of the entire forest community.
In conclusion, the plants, animals, and protists living in a forest make up a community, which refers to the interactions and interdependencies among different species within a specific ecosystem.

Leech is a member of Phylum Annelida. Members of Phylum Annelida have body surface marked out into segments or metameres, its body surface is covered by cuticles. Thus, it is called ringworm. Starfish belong to Echinodermata and snails belong to Mollusca.
Hence the correct answer is option “A”

Explanation:
The taxonomic hierarchy is a system used to categorize and classify organisms based on their characteristics and evolutionary relationships. It consists of several levels, including species, genus, family, order, class, phylum, kingdom, and domain. As one moves up the hierarchy from Species to Kingdom, the number of common characteristics generally decreases. This can be explained by the following points:
1. Diversity of Species: There are millions of different species on Earth, each with its own unique set of characteristics. As we move up the hierarchy, we are grouping together more and more species that share common characteristics, but also have their own unique features.
2. Increasing Generalization: At the species level, organisms are very specific and have distinct characteristics that differentiate them from other species. However, as we move up the hierarchy, the groups become more general and encompass a wider range of organisms. This means that the common characteristics shared by organisms in higher taxonomic levels are fewer and more general.
3. Evolutionary Divergence: As organisms evolve and adapt to different environments, they develop new characteristics that help them survive and reproduce. This leads to the formation of new species with distinct features. Therefore, as we move up the taxonomic hierarchy, the number of common characteristics decreases due to the increasing divergence of species.
In conclusion, as one goes from Species to Kingdom in a taxonomic hierarchy, the number of common characteristics generally decreases. This is because higher taxonomic levels encompass a wider range of organisms with fewer shared characteristics.

Filaria isa disease caused by Wuchereria bancrofti, it is not an aquatic animal, whereas, Hydra is a coelentrate and is a freshwater organism. Jelly fish is a marine animal. Corals are cnidarians and Marine invertebrates.

Scientific name of an organism:
The scientific name of an organism is a unique binomial name given to it by scientists. It consists of two parts: the genus name and the species name. The scientific name is standardized and used by scientists all over the world to avoid confusion and ensure accurate communication. Let's break down the options given and determine the correct answer:
A: May refer to more than one species:
No, the scientific name of an organism is specific to a particular species. It helps to differentiate between different species and avoids ambiguity.
B: May have more than one genus:
No, the scientific name follows the binomial nomenclature system, which consists of a genus name and a species name. Each organism is assigned a unique combination of genus and species names.
C: Varies according to the native language of scientists:
No, the scientific name is an international standard and is independent of the native language of scientists. It is based on Latin or Greek roots and remains the same across different languages.
D: Is the same for scientists all over the world:
Yes, this is the correct answer. The scientific name of an organism is universally recognized and used by scientists worldwide. It ensures consistency and enables effective communication and identification of organisms.
In conclusion, the scientific name of an organism is the same for scientists all over the world. It follows a standardized system and consists of a unique combination of genus and species names.

Two-chambered heart occurs in fish.
Fish have a unique circulatory system compared to other animals. They have a two-chambered heart, which means their heart has two main chambers - the atrium and the ventricle. This type of heart structure is less complex than the hearts of other animals with more chambers.
Explanation:
Fish have a specialized circulatory system that allows them to efficiently extract oxygen from water and deliver it to their tissues. Here's how a two-chambered heart works in fish:
1. Atrium: The atrium is the upper chamber of the heart. It receives deoxygenated blood from the fish's body through the veins.
2. Ventricle: The ventricle is the lower chamber of the heart. It receives blood from the atrium and pumps it out to the fish's gills.
3. Gills: Fish have gills, which are specialized organs for gas exchange. As blood is pumped from the ventricle to the gills, it flows through the tiny blood vessels in the gills, where it picks up oxygen from the surrounding water and releases carbon dioxide.
4. Systemic circulation: After the blood is oxygenated in the gills, it is delivered to the fish's body tissues through a series of blood vessels. This is known as systemic circulation.
5. Deoxygenated blood: Once the oxygen is delivered to the body tissues, the blood becomes deoxygenated and returns to the heart through veins to start the cycle again.
It's important to note that fish have a single circulation system, meaning that oxygenated and deoxygenated blood mix together in their circulation. This is different from other animals, such as mammals and birds, which have a four-chambered heart and separate systemic and pulmonary circulation.
In conclusion, fish have a two-chambered heart, which is adapted to their aquatic lifestyle and allows them to efficiently extract oxygen from water. This type of heart structure is unique to fish and differs from the hearts of other animals.

The monerans , mostly bacteria, came first: more than 3 billion years ago.

Monerans are single-celled, with little internal structural complexity.

In spite of their structural simplicity, they represent great biochemical diversity.

Monerans include: producers (photosynthetic or chemosynthetic) and decomposers.

In gymnosperm, male and female gametophytes are within sporangia on sporophyte. Pollen grain in microsporangium is carried in the air and come in contact with ovule on megasporophyll. After fertilization, zygote forms embryo and ovule forms seed. Seeds are not covered. In bryophytes and pteridophytes, zygote produces sporophyte and there is no seed formation. In thallophyte, reproduction is mainly asexual and when sexual it is isogamous, anisogamous or oogamous.