Variation in the DNA coping and due to sexual reproduction is the only property which gives the basic design. Thus after a long period of time; due to evolution in various environmental conditions organisms have a varied body design; which ultimately helps in its survival.

Varied Body Design in Organisms: The Role of Body Plans

Organisms exhibit a wide range of body designs, which is a result of their evolutionary history and adaptation to different environments. These body designs, also known as body plans, are characterized by specific structural and functional features that distinguish one organism from another. The property that gives the basic difference in body design is called "body plan."

What is a Body Plan?
A body plan refers to the overall structural organization of an organism, including its body symmetry, segmentation, and arrangement of major organ systems. It serves as a blueprint for the development and functioning of an organism, determining its overall shape, mobility, feeding strategies, and other physiological characteristics.

Key Factors Influencing Body Plan Variation:
The variation in body design among organisms can be attributed to several key factors:

1. Evolutionary History: The diverse body plans observed in the living world today are the result of millions of years of evolution. The gradual accumulation of genetic mutations and natural selection has led to the development of different body designs that are better suited to specific ecological niches.

2. Environmental Pressures: Organisms are constantly subjected to selective pressures exerted by their environment. These pressures can include predation, resource availability, competition, and climate. Different environments favor the evolution of specific body plans that enhance an organism's survival and reproductive success.

3. Genetic Variation: Genetic variation within a population provides the raw material for evolutionary change. Mutations in the DNA sequence can introduce new traits or modify existing ones, leading to the development of novel body plans over time.

Types of Body Plans:
Organisms can be broadly classified into distinct body plan types, each exhibiting unique characteristics:

1. Radial Symmetry: Radially symmetrical organisms, such as jellyfish and sea anemones, possess body parts arranged around a central axis. This symmetry allows them to interact with their environment equally from all directions.

2. Bilateral Symmetry: Bilateral symmetry is observed in animals like humans, where the body can be divided into two mirror-image halves along a sagittal plane. This design aids in directed movement and the development of specialized sensory organs.

3. Segmentation: Many organisms, such as earthworms and arthropods, exhibit segmentation, where their bodies are divided into repeated units called segments. This allows for greater flexibility, specialization, and redundancy of body parts.

4. Body Cavity: The presence or absence of a body cavity also influences body design. Organisms with a true body cavity, like humans, possess well-defined spaces between the body layers that allow for the development and movement of internal organs.

Conclusion:
The varied body designs observed in organisms are a result of their evolutionary history, environmental pressures, genetic variation, and the specific body plan types they possess. These body plans enable organisms to adapt to their surroundings, perform essential functions, and thrive in diverse ecological niches. Understanding the basic differences in body design is crucial in unraveling the complexity and diversity of life on Earth.