Problem 69 - Objective Biology for NEET

Question

Example of ctenophores is (a) Pleurobrachia (b) Ctenoplana (c) Both (a) and (b) (d) None of these

Step-by-Step Solution

Answer

The correct answer is (c) Both (a) and (b). Both Pleurobrachia and Ctenoplana are examples of ctenophores.

Step 1: Identify the biological concept

Determine which biology area this addresses.

Step 2: Recall relevant principles

Review key concepts.

Step 3: Apply knowledge

Use biological reasoning.

Step 4: State the answer

The answer is: The correct answer is (c) Both (a) and (b). Both Pleurobrachia and Ctenoplana are examples of ctenophores.

Key Concepts

Pleurobrachia

The Pleurobrachia, often known as the "Sea Gooseberry," is a fascinating example of a ctenophore. These creatures are found widely across the world's oceans, known for their round, almost ball-like shape.
Pleurobrachia are small, transparent gelatinous animals characterized by their bioluminescent properties. Often they exhibit beautiful patterns of light, making them mesmerizing to observe in their dark marine environments.
One of the most notable features of the Pleurobrachia is its eight rows of cilia that look like "combs". These combs glide along their surface and help them swim efficiently through the water. This movement is quite graceful, allowing them to drift and move while catching plankton with their tentacles.
Here are some key features of Pleurobrachia:

• Round, transparent body
• Eight ciliary combs for locomotion
• Bioluminescence
• Plankton-based diet

Understanding Pleurobrachia gives insight into the delicate and complex nature of marine ecosystems.

Ctenoplana

Ctenoplana is another intriguing member of the ctenophore family. Unlike the more spherical Pleurobrachia, Ctenoplana has a more flattened or elongated appearance. This unique shape helps them navigate through different marine environments effectively.
Ctenoplana are known for their remarkable adaptation skills. They do not have the same comb-like rows that Pleurobrachia have, but they still exhibit cilia on their bodies to aid their movement through water.
Another notable aspect of Ctenoplana is their lifestyle, often attaching themselves to surfaces like rocks or seagrasses in the ocean. This further illustrates their adaptability in various marine habitats.

• Flattened, elongated body form
• Presence of cilia for movement
• Adaptability to different marine environments

Marine Biology

Marine biology is the study of life in ocean environments. It covers an incredible diversity of organisms, from tiny plankton to giant whales. Ctenophores like Pleurobrachia and Ctenoplana fall under this study, adding to the complexity of the marine food web.
Exploring the marine world, marine biologists like to understand how these creatures interact with their environments. They study aspects such as organism behaviors, reproduction, and feeding habits. The study of ctenophores helps highlight the evolutionary adaptability and ecological roles these simple yet complex creatures play in ocean ecosystems.
Key areas of focus in marine biology:

• Ecosystems and habitats
• Marine biodiversity
• Interactions between marine organisms

Learning about marine biology expands our understanding of our planet and the crucial balance within ocean environments.

Comb Jellies

Comb jellies, or ctenophores, are mesmerizing creatures that inhabit marine environments worldwide. Named for their distinctive 'combs' made of ciliary rows, these jelly-like animals use their combs to move gracefully through water.
Comb jellies differ significantly from jellyfish, as they lack stinging cells and instead rely on sticky cells called colloblasts to catch their prey. This makes them unique in how they interact with their environment and capture food like plankton.
They are believed to be among the oldest existing animal lineages, giving scientists a glimpse into early evolutionary processes. Their role in marine biology is substantial, as they serve as both predators and prey within their ecosystems.

• Use ciliation for movement
• Lack stinging cells, using colloblasts instead
• Ancient evolutionary lineage

Through studying comb jellies, we can learn a lot about oceanic life's intricacy and history.