Protists - Examples and Characteristics of Protists

len Alfred Ajibola - Sun, 28th April, 2019 @ 14:35: PM

Topics in Biology

Tropical savanna explained with its characteristics Ecological pyramid explained with its importance and limitations Hindbrain: Medulla Oblongata and its features Food web explained with examples Biology Scheme of Work, SS1, First Term Biology Scheme of Work, SS1, 2nd Term Biology Scheme of Work, SS1, 3rd Term Male accessory sex organs: Seminal vesicles and bulbourethral glands Scrotum and its contents: Testicles Brain: Introduction to the human brain Forebrain: Lobes of the cerebrum and their functions Cerebellum: Parts and functions of the cerebellum Midbrain: Division and functions of the midbrain Negative feedback mechanism in homeostasis Arterial disorders explained with their causes Types of desert and their characteristics Characteristics of tropical rainforest Swamp forest: What are swamp forests? Characteristics of swamp forests Savanna biome: Concept of the savanna

Academic Questions in Biology

Please click here to see all Questions and Answers

In a food chain, the primary consumers are classified under trophic level  _____.

  • A. Zero

  • B. One

  • C. Two

  • D. Three

  • E. Four

  • F. Five

Cold blooded animals are referred to as _____.

  • A. Homeotherms

  • B. Endotherms

  • C. Poilokitherms

  • D. Ectotherms

  • E. Thermotherms

  • F. None of the above

All reptiles are vertebrates.

  • A. True

  • B. False

_____ cells are responsible for the formation of osteoblasts.

  • A. Osteocytes
  • B. Chondrocytes
  • C. Chondroblasts
  • D. Osteoclasts
  • E. Osteoprogenitor cells
  • F. Osteoblastic

_____ is a bone that constitute the axial skeleton.

  • A. Clavicle
  • B. Scapula
  • C. Patella
  • D. Radius
  • E. Sternum
  • F. Femur

Which of the following is false concerning cartilages and bones?

  • A. Cartilage does not have a direct blood supply while bones have direct blood supply
  • B. The process of ossification replaces a cartilage to bone
  • C. The protein that makes up cartilage is called chondrin while that that makes up bone is called ossein
  • D. Cartilage grows from both ends while bones grow from one of its epiphysis
  • E. They both have living cells within them
  • F. Haversian system is absent in cartilage but present in bones

A diagram showing the movement of energy through a food chain is called a _____.

  • A. Food Chain
  • B. Food Web
  • C. Food Energy
  • D. Food Link
  • E. Food Flow
  • F. Food Pyramid

Which of the following is NOT a part of the wrist bones (or carpal bones)?

  • A. Cuboid
  • B. Scaphoid
  • C. Hamate
  • D. Triquetral
  • E. Pisiform
  • F. Trapezium

What are living organisms?

A living organism is defined as anything that has life. We know for sure that plants and animals are living organisms because they fulfill all the basic characteristics necessary for life.

Below are the basic characteristics of life:

  1. Movement
  2. Respiration
  3. Nutrition
  4. Irritability
  5. Growth
  6. Reproduction
  7. Death
  8. Adaptation
  9. Competition
  10. Please read more on basic characteristics of life here.

It is noteworthy to state that plants and animals are not the only forms of living organisms. In this regard, we have other forms of living organisms that aren't plants nor animals.

There are millions of organisms that are neither plants nor animals. Generally, the classification of organisms into kingdoms have given more insight about life. Meanwhile, recall that biology is the study of life.

You can read amazing facts in biology here.

Anything that has life must belong to a kingdom.

Classification of living organisms

As stated earlier, living organisms are classified into kingdoms. As an instance, human beings, insects and birds are all classified under kingdom 'animalia'. Also, trees, shrubs and grasses are generally classified into the kingdom 'plantae'.

Below are the respective kingdoms with regards to the classification of living organisms:

1. Archae: They include those bacteria that survive under extreme environmental conditions like the hot acidic springs and salt lakes. The kingdom 'archae' may also also be referred to as archaebacteria.

2. Monera: The organisms found here are called monerans. They include bacteria and blue-green algae.

3. Protista: The organisms found here are called protists. Protists are the focus of this article.

4. Fungi: Organisms belonging to this kingdom are generally called fungi. Mushrooms and yeasts are examples of fungi.

5. Plantae: The organisms found here are called plants. All plants belong to this kingdom.
Please read on the differences between plants and crops here.

6. Animalia: All animals belong to this kingdom. Ants, hydra, cats, fishes, birds, reptiles and humans belong to kingdom animalia.
Please read on reptiles and their characteristics here.

The classification above was developed by a Swedish botanist named Carolus Linnaeus (1701 - 1778). This is the modern method of classification; and it's termed 'taxonomy' or 'systematics'.

What are Protists?

Protists are neither plants nor animals nor fungi nor bacteria; they are simply 'protists'.

In simple terms, an organism belonging to kingdom protista is referred to as a protist; just as those belonging to kingdom plantae are called plants.

All protists are eukaryotic organisms. Being eukaryotic imply that their cell structure has a nucleus bordered by a membrane. They also have organelles in their cytoplasm.

Generally, protists live in an aquatic or fluidly or moist habitat.

Please read on swamp forests here.

All protists do not share similar characteristics. This is because some have got 'animal-like' characteristics while others are 'plant-like'. An animal-like protist means that such protists have got some features found in animals. For instance, their cells have a cell membrane. Meanwhile, recall that all animals have a cell membrane as the outermost layer of their cell.

When a protist is plant-like, it means that they have cell wall and chloroplast respectively. In this regard, such plant-like protists can manufacture their own food. Also, recall that all plants have chloroplasts and a cellulose cell wall.

Please read more on autotrophic nutrition here.

Understand that a few protists can be fungi-like since they may reproduce by forming spores.

Generally, all protists are commonly grouped together because they do not specifically fit into any other kingdom.

Examples of protists includes: amoeba, paramecium, euglena, chlamydomonas, plasmodium, kelp, slime molds and water molds.

Some protists are single celled (unicellular) while others are colonial (form colonies) and multicellular (made up of more than one cell).

In terms of size, a few protist can be very large. An example of a large protist is the kelp. However, most protists are microscopic in size. Examples are amoeba,. paramecium and euglena.

A protist can can be free-living or parasitic. An example of a free-living protist is the amoeba. Conversely, a plasmodium is a parasitic protist. Also, understand that a few protist may be saprophytic.

Below is a diagram showing various Protists.

Protists - Len Academy


Characteristics of Protists


1. Locomotion

This is the ability of an organism to move from one point to another.

Although some protists are non-motile (cannot move from one point to another), others exhibit locomotion via a variety of locomotary organelles.

Below are some protists and their locomotary organelles:

  • Amoeba --> Pseudopodia
  • Paramecium -->  Cilia
  • Euglena --> Flagella
  • Chlamydomonas --> Flagella

Examples of non-motile protist are plasmodium and Toxoplasma gondii.

Note: Slime mold and water mold are protists that exhibit little movement.

Please read on some Amazing Facts in Biology here.


2. Nutrition

Certain protists are photosynthetic autotrophs (that is, they can manufacture food by utilizing the energy from sunlight). Examples are euglena and algae.

Conversely, some are heterotrophic (that is, they cannot produce their own food and hence rely on readymade food). Examples are amoeba and paramecium.

The protist plasmodium is the causative agent for malaria. (It is sometimes referred to as the malaria parasite). It undergoes a parasitic kind of nutrition; which is a type of heterotrophic mode of nutrition.

Please read on Micro-organisms causing Food, Water and Air Borne Diseases here.

Note: Some protists are both autotrophic and heterotrophic. Euglena is an example.


3. Cell Structure

Most are unicellular. Amoeba, paramecium, euglena, chlamydomonas and  plasmodium are examples of unicelluler protist.

A few protists are multicellular; for example, kelp, slime molds and algae.


4. Reproduction

Reproduction is typically asexual but sometimes, sexual reproduction does occur.

Binary fission is a form of asexual reproduction that occurs in Amoeba.

Please read on Reproduction in Plants here.

Plasmodium falciparum may undergo sexual reproduction at some stages in it's life cycle.

Please read on the Male Reproductive System here.


5. Habitat

They generally live in an aquatic habitat. This is usually a fresh water in most cases. Fresh water habitat include ponds, lakes, rivers and streams.

Note: Seas and Oceans are salt water. Any water body that isn't a sea or an ocean is much likely to be a fresh water.

Please read on Tropical Rainforest and Savanna here.


6. They are Eukaryotic organisms 

Being eukaryotic implies that their cell structure have a well defined nucleus and cell membrane.

Need more answers to this topic? Please enter your search below:

Kindly share this article via the links below:


Please contact Alfred via the above whatsapp link for a comprehensive online academic coaching in Biology, Chemistry, Basic Science and ICT

Click here to read the amazing features of the Len Academy Smart School Software. However, contact Alfred through the above whatsapp link if you require a standard website for your business or school at an affordable price

Please click here to follow Len Academy on Google News.

Please like and follow our official facebook page here for great educational write-ups.

You can follow Len Academy on twitter here.Thank you.

Please Register here or Login here to contribute to this topic by commenting in the box below.

Amazing facts in Biology

Cockroach is the fastest land animal on six legs

Laughing ape - Len Academy

Like humans, all apes laugh when tickled

Ostrich eye and brain - Len Academy

An ostrich's eye is bigger than its brain

The upper front teeth are missing in giraffes. Meanwhile, like an adult human, a fully grown giraffe has 32 teeth but most are positioned at the back of their mouth

Slugs have four noses

Most insects hatch from egg but aphids give birth to their young alive

Bats aren't birds, rather, they are mammals. Infact, they are the second largest order of mammals after rodents. We have over 1,400 species of bat. Globally, they make up about 20% of all classified mammal species

Panda eating bamboo - Len Academy

99% of a panda's diet is bamboo. They may eat fish or other small animals occasionally

When attacked by insects, lima beans plant will often command parasitic wasps to their defence.

When the leaves of the lima bean's leaves are eaten by insects, the plant gives off a substance that signals parasitic wasps to swam in, destroying its enemies (the leaf-eating insects) in the process

Frogs drink water through their skin


For a thing to be considered living, it must possess all the basic characteristics of life. These include:

  1. Movement

  2. Respiration

  3. Nutrition

  4. Irritability or Sensitivity

  5. Growth

  6. Excretion

  7. Reproduction

  8. Death

  9. Adaptation

  10. Competition

Please read the explanations on all the basic characteristics of life here

During strenuous exercises like sprinting or running, your body may actually work in the shortage of oxygen. During this time, your body owes oxygen (called oxygen debt) and it must be replenished or repayed after the exercise is stopped. This is why you breathe excess of oxygen after you stopped the exercise.

This is the concept of anaerobic respiration

Food Chain - Len Academy

A food chain is a diagram that shows the relationship between plants and animals within a habitat on the basis of how they rely on each other for food.

Note: Habitat is a place where an organism live. It is of three types:

  • Terrestrial (Land)
  • Aquatic (Water)
  • Arboreal (Treetops)

You can read on food chain here

The term Biology originated from two Greek words. They are:

  • Bios: means life.

  • Logos: means knowledge or to study.

Biology can therefore be defined as the study of life

Anything that has life is generally considered as a living organism (or organism). All living organisms must be able to carry the following activities:

  1. Movement

  2. Respiration

  3. Nutrition

  4. Irritability or Sensitivity

  5. Growth

  6. Excretion

  7. Reproduction

  8. Death

  9. Adaptation

  10. Competition

The above listed points are often regarded as the basic characteristics of life. You can memorize them using the acronym -> MR. NIGER DAC.

You can read on the introduction to biology and the basic characteristics of life here

The gas used in the manufacture of food by plants is Carbon dioxide or Carbon(IV)oxide or CO2

Plants manufacture food through a process called photosynthesis.

Please read on photosynthesis here

It is noteworthy to state that plants are the only orgnisms that take away CO2 from the atmosphere