You can easily identify the difference between invertebrates and plants by looking at their physical features because there is a substantial difference in their morphologies.
Are Plants Invertebrates? Plants are not invertebrates because they belong to the kingdom Plantae, possess a cell wall, reproduce by sexual and asexual means, live in varying habitats, and remain fixed at locations. They are autotrophic organisms or producers, while invertebrates are heterotrophs.
Animals are classified into vertebrates and invertebrates based on the difference in the presence of spines, as a few animals lack backbone and internal skeletons.
Plants are an entirely different category of living organisms and are not considered invertebrates or vertebrates because they are not animals.
What is considered an invertebrate?
Invertebrates are animals with distinguishing characteristics, like the absence of a vertebral column, making them different from vertebrates because they possess spines.
It involves many organisms with unicellular or multicellular bodies, like protozoa, crustaceans, and arthropods living on land and in marine environments.
Moreover, these organisms are tiny to medium-sized creatures ranging between microscopic ticks or mites and giant squids.
Some have segmented bodies and possess six legs, like ants, bees, termites, beetles, and flies, while others have wingless bodies and eight legs, like tarantulas and spiders.
However, earthworms and snails have soft bodies and lack legs as they crawl on the ground by contracting their muscular bodies. Others are water-dwelling creatures, like crabs and shrimps.
Almost 85 to 90% of animals’ population on earth are invertebrates as they occupy varying habitats and adapt to different living conditions: deserts, wettest rainforests, and deep oceans.
This group of invertebrates does not include plants because these belong to a different kingdom due to extreme variations in lifestyle, behavior, and morphological features.
Why are plants not invertebrates?
There are many differences between plants and invertebrates at the molecular or cellular level as the structure of their cell varies, leading to many other changes in their behavior and habitat.
Belong to Kingdom Plantae
They belong to a separate kingdom because they do not share morphological and behavioral characteristics with animals, so Linnaeus classified them into a separate group.
Moreover, these living organisms have their distinct divisions, including bryophytes consisting of non-vascular plants like mosses, hornworts, and liverworts.
Gymnosperms are seed-producing plants, but their seeds are not covered by fruits, like conifers and gnetophytes, while angiosperms are flowering plants having seeds within a fruit.
Furthermore, it includes ferns or horsetails that are seedless and homosporous, having a vascular system and producing megaphylls.
However, there are different divisions of invertebrates, like mollusks, annelids, and arthropods, containing organisms that cannot reach a height of several feet above the ground.
There is a difference in their methods of obtaining food because plants are autotrophic organisms and prepare their food through a process of photosynthesis.
Moreover, they are also known as producers because they consume light and carbon dioxide to produce complex carbohydrates and oxygen.
However, invertebrates are heterotrophic organisms dependent on their food on trees and other animals because they cannot prepare their food.
Accordingly, they suck secretions or floral nectar and eat tiny insects and smaller animals to meet their body requirements for energy.
So, they are different from invertebrates in their mode of nutrition because plants are producers while they depend on nature for food and are known as consumers.
Possess cell wall and chloroplast
You can see changes between these two different types of living organisms at the cellular level because their cell structure is different to some extent.
Plants possess cell walls containing cellulose microfibrils, hemicellulose, or pectin molecules, while cells in invertebrates do not have cell walls as they only contain a cell membrane.
In addition, the cell wall helps maintain a rigid structure to keep the internal content within the cell so that it can tolerate osmotic and mechanical stress.
They have chloroplasts and plastids involved in photosynthesis, which are absent in soft-bodied animals because they do not capture light to use it for photosynthesis.
Moreover, their cells store energy in different forms, as plants store it as starch, while animals make glycogen to conserve energy for later use.
Remain fixed at locations
Plants cannot move to different locations and remain fixed in their place due to their roots expanding deep into the soil, providing good support to their bodies.
These roots anchor it within the soil by reaching a depth of a few meters so the plant remains upright in a single location. They can bend and grow higher but remain fixed in one place.
Many irregular root hair or branches emerge from the main root within the soil that help improve the stability during strong wind or other external stresses.
In contrast, the invertebrates have legs to support movement on the ground, while some contract their body muscles to crawl on solid surfaces.
The marine creatures move by water currents as their bodies reach different locations by following the water current direction as water pushes their bodies along it.
Difference of morphology
Many morphological variations are there between plants and invertebrates as their bodies are organized into different manners and have different shapes and sizes.
The plant body is divided into 6 distinct parts, including the roots, seeds, leaves, flowers, stems, and fruits that can be clearly distinguished from each other.
However, the body of invertebrates contains 3 major segments, including the head, thorax, and abdomen, while they also possess 6 legs, 2 antennae, mandibles, and a few other structures.
Plants do not possess any chewing, biting, and stinging organs for defensive purposes that are present in invertebrates because they have their own defense system.
In addition, you can find a lot of variations in the body length, height, and shapes of both living organisms, but their basic body plan differs.
Plants have sexual and asexual reproduction, while invertebrates can only reproduce by sexual means in which every offspring differs from a parent.
The sperms and eggs fertilize together to produce offspring in animals, and a few flowering plants are dependent on pollination involving the transfer of pollens to female reproductive organs.
However, the asexual reproduction in plants produces offspring genetically identical to their parents. Apomixis is common in plants involving the production of seeds without fertilization.
In addition, vegetative reproduction, budding, binary fission, parthenogenesis, and fragmentation are also common ways of reproducing asexually that are not common in animals.
Are there any similarities between plants and invertebrates?
Plants and invertebrates are completely different living organisms as they belong to two different kingdoms due to extreme variations in their features and evolutionary histories.
They have different body plans, live in different habitats, and obtain food using other methods. However, these two distinct organisms have some similarities, as both are eukaryotes.
They are multicellular organisms containing millions of cells that collectively form tissues and organs responsible for various functions.
In addition, plants have cuticles on their outer surface for protection from the environment, and invertebrates, particularly arthropods, have exoskeletons to protect internal body tissues.
Moreover, both organisms can reproduce sexually, fertilizing male sperm with female eggs to produce offspring or seeds.
Furthermore, both can detach their body parts after an injury or a threat, as plants can remove their leaves or branches, while some invertebrates detach their limbs to ensure survival.