Biology Jokes

Who says science jokes are not funny? Below you can see some of the best Biology jokes we know, along with short explanations of the more obscure of them.

Do you know any funny Biology jokes yourself? Let us know in the comment section below.

Two blood cells met and fell in love. Alas, it was all in vein.

A clever wordplay with the words “vein” and “vain”.

Pavlov is sitting at a pub, enjoying a pint. Suddenly the phone rings and he jumps up shouting, “Oh no, I forgot to feed the dog!”

Pavlov is a physiologist who used to ring a bell every time he fed his dogs. After some time, he noticed that ringing the bell by its own caused salivation in his dogs, even if he didn’t offer them any food.

“I wish I was adenine, then I could get paired with U.”

In RNA (Ribonucleic acid), adenine (A) makes a “base pair” with uracil (U).

“What did one sister chromatid say to the other?”
“Stop copying me.”

“Sister chromatids” are two identical chromatids (replicated chromosomes), which are joined with each other.

What does DNA stand for? National Dyslexia Association.

Dyslexia is a reading disorder, which causes various troubles during reading, even for people with normal intelligence. If read correctly, the abbreviation for National Dyslexia Association should be NDA, not DNA.

“What did the stimulus do to the neuron after they got married?”
“It carried it over the threshold.”

The “threshold” is the depolarization level over which a stimulus must carry the neuron, in order for an action potential to be fired.

An infectious disease enters a bar. The bartender says, “We don’t serve your kind here”. The disease replies, “Well, you are not a very good host.”

The word “host” has several meanings, one of which is “a person who accommodates guests”, and another one is “an animal or a plant in which a parasite lives”.

The scientists have just found the gene for shyness. They would have found it earlier, but it was hiding behind two other genes.

“What is the fastest way to determine the sex of a chromosome?”
“Pull down its genes.”

Word play with the words “genes” and “jeans”.

One lab rat says to another:
I’ve got my scientist so well trained that every time I push the buzzer, he brings me a snack.”

“Girl, you are so hot, you denature my proteins.”

When things get hot, proteins denature, i.e. lose their shape and structure.

“What did Gregor Mendel say when he founded genetics?”

Gregor Mendel made his experiments using pea plants.

“What is sleeping brain’s favorite rock band?”

REM stands for “rapid eye movement”, which occurs during sleep.

Puzzle Tournament 3

Puzzle Prime’s third puzzle tournament was organized on January 31, 2021. Congrats to Elyot G. who is once again a winner! You can see the problems and the rankings below.

Elyot G.

You have 60 minutes to solve 5 puzzles, each worth 1 point. Upload your solutions as a pdf, document, or image, using the form below. Good luck!

Time for work: 1 hour

1. Constellation

by Raindrinker

Connect the stars with lines, so that the number inside each star corresponds to the number of lines connected to it, and the number in each barrier corresponds to the number of lines intersecting it.

Note: The stars in the corners cannot be connected, since the lines would pass through other stars.


2. Lineon

by Blaž Gracar

Move one of the Friends to the Exit Point.

Draw lines to move Friends. A move is connecting a point on the Grid to another point on the Grid by drawing a straight line. The line can be made in any direction, as long as it connects exactly two points and doesn’t cross or touch another line.

You move each Friend as many times as it says on the Timeline, starting with the topmost Friend and continuing in the order all the way down to the bottom one.

One of the Friends must move to the Exit Point, but before he does that, each of the Key Points must be already connected with a line. A Wall is a double line and no Friend can cross or touch it.


3. Vinculus

by Dr. DJ Upton

Circles are particles and lines joining them are bonds. The objective is to find all the hidden values, following these four rules:

  1. Particle values must be the sum of their bond values.
  2. Particles can have the following values: 0, 1, 2, 4, 8, 12, 16.
  3. Bonds can have the following values: 0, 1, 2, 4.
  4. If two particles have the same value, the bond between them must have value 0.

4. Chess Connect

by Puzzle Prime

The starting and ending positions of 6 chess pieces are shown on the board. Find the trajectories of the pieces, if you know that they do not overlap and completely cover the board.

Notes: The pieces can not backtrack. Two trajectories can intersect diagonally but can not pass through the same square. Only the Knight has a discontinuous trajectory.


5. Murder Mystery

by Hiroji Osaka

In the three murder cases below, you can read the testimonies of all suspects. For each case, find who the killer is, knowing that no 2 people are in the same row or column, and that the killer was alone in a room with the victim.




Elyot G.010113
Leong W.010001
Chandan R.010001


The TOP 3 players will win codes for some of our favorite puzzle video games. Thanks to Other Tales Interactive, Thomas Bowker, and Daniel Nora for supporting our tournament.

Escape the Room: The Cursed Dollhouse


With the huge success of real-life Escape Rooms all around the world, more and more puzzle manufacturers have been trying to recreate the experience with their solve-at-home kits. ThinkFun‘s latest offering, Escape the Room: The Cursed Dollhouse, is possibly the closest you can get to the real thing, so far.

The setup of “The Cursed Dollhouse” is quick and simple. Within a few minutes you get to build a cardboard model of a dollhouse, turn on the recommended soundtrack of creepy music, and light up a few candles to get into the right mood. Once you do this, you can start reading the story of the house and unravel its mysteries.

You begin the adventure in the living room, where you have to solve several puzzles, involving a broken bookshelf, a dusty carpet, and a spiderweb on the wall. Then, you make your way through the rest of the house: kitchen, bathroom, bedroom, until you get to the attic. Each of the rooms you visit contains multiple objects, including hidden ones, which you need to use in order to solve its three challenges. Once you solve a challenge, you get a cryptic symbol which you must enter in the “solution wheel”. Get the three symbols correctly and proceed to the next room.

As you progress, you will encounter various puzzles, including many mechanical ones. You will have to cut, fold, entangle, and do all kinds of fun activities. The puzzles are logical and satisfying to solve. There were one or two which my group found a bit confusing, but fortunately, ThinkFun has created a website, where players can get small hints without spoiling the entire puzzles. In the end, all participants were very happy with the time we spent playing together.

While the price of “The Cursed Dollhouse” is a bit steep, the game provides a lengthy and immersive experience which justifies the cost. It also can be replayed by another group of people using the provided printable forms from the official website.

  • 1-4 players, 13 years and up
  • over 30 puzzles to solve within 2.5 hours
  • realistic small-scale Escape Room experience
  • puzzles are re-printable from the official website


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Topple Magazine


Topple is a new online magazine that can be printed out and solved with pen and paper, the old-fashioned way. The price of each issue is just a meager $1, and for that amount you get a PDF of about 10 pages and up to 20 puzzles.

The authors of the magazine have put efforts to provide a large variety of puzzles, so that everyone will find something they like. There are interesting trivia questions, rebuses, grid logic puzzles, as well as some unique challenges I have never encountered before. The number of puzzles in the magazine keeps increasing with each next issue:

Issue 1: 7
Issue 2: 7
Issue 3: 10

Issue 4: 10
Issue 5: 10
Issue 6: 12

Issue 7: 16
Issue 8: 18
Issue 9: 18

The quality of the puzzles keeps improving as well, as you can see from these two identical puzzles, second one of which has updated artwork.

Before you purchase the magazine, you can take a look at the 4-page sampler we have provided below.

If you enjoy the Topple puzzles as much as we do, we recommend you to get the latest issue and then keep buying the older ones in a reverse order. At just $1, it will be hard to find something that provides better value for the money.

  • appropriate for all ages
  • PDF booklet for easy printing
  • about 10-20 puzzles per issue
  • fun old-school vibes
  • just $1


* This post contains affiliate links. We may receive a small compensation if you make a purchase.

Brain Drop Podcast

Brain Drop is a new puzzle podcast by Brian Hobbs, released on a (mostly) weekly basis. In each episode, Brian presents 3 new puzzles and shares the solutions of the puzzles from the previous week. He uses professional voicework, music, and sound effects, to set up the mood and make his show more entertaining. Click the banner below to check out Brain Drop and see if you can answer Brian’s latest set of puzzles!

Rapunzel and the Prince

The evil witch has left Rapunzel and the prince in the center of a completely dark, large, square prison room. The room is guarded by four silent monsters in each of its corners.  Rapunzel and the prince need to reach the only escape door located in the center of one of the walls, without getting near the foul beasts. How can they do this, considering they can not see anything and do not know in which direction to go?

The prince must stay in the center of the room and hold Rapunzel’s hair, gradually releasing it. Then, Rapunzel must walk in circles around the prince, until she gets to the walls and finds the escape door.

Is This Prime?

In the past few days, I, my friends, and a whole lot of Twitter people have been trying to beat each other’s scores in the game “Is This Prime?”.

The game itself is simple; you are shown random integers on the screen and you need to guess whether they are prime or composite. Since most presented numbers are between 1 and 200, after a couple of games, players naturally memorize them. However, this is a good opportunity for students to review some main number division rules.

  1. Numbers that end with an even digit are divisible by 2. If the number formed by the last 2 digits of a number is divisible by 4, the original number is also divisible by 4. If the number formed by the last 3 digits of a number is divisible by 8, the original number is also divisible by 8.
    • 536 is divisible by 2 because 6 is an even digit
    • 1348 is divisible by 4 because 48 is divisible by 4
    • 71824 is divisible by 8 because 824 is divisible by 8
  2. Numbers that end with 5 are divisible by 5. Numbers that end with 25, 50, 75, or 00 are divisible by 25.
    • 45 is divisible by 5
    • 675 is divisible by 25
  3. Numbers whose sum of digits is divisible by 3 are divisible by 3. Numbers whose sum of digits is divisible by 9 are divisible by 9.
    • 144 is divisible by 3 because 1+4+4=9 is divisible by 3
    • 1638 is divisible by 9 because 1+6+3+8=18 is divisible by 9
  4. If the difference between the sum of the digits in odd places and the sum of the digits in even places is divisible by 11, the number is divisible by 11.
    • 121 is divisible by 11 because 1+1-2=0 is divisible by 11
    • 209 is divisible by 11 because 2+9-0=11 is divisible by 11
    • 1628 is divisible by 11 because 1+2-6-8=-11 is divisible by 11
  5. If the number before the last digit minus twice the last digit is divisible by 7, the original number is also divisible by 7.
    • 161 is divisible by 7 because 16-2×1=14 is divisible by 7
    • 371 is divisible by 7 because 37-2×1=35 is divisible by 7
    • 1589 is divisible by 7 because 158-2×9=140 is divisible by 7

All the rules above apply in both directions, e.g. if the sum of the digits of a number is not divisible by 9, then the number itself is also not divisible by 9. There are more complicated rules that apply to larger numbers but the chances are you will never get to use them. If you are curious to learn more about them, go to the bottom of this article.

Once we know the main number division rules well, we are ready to play the game! Here are a few tips for getting high scores:

  1. Memorize as many numbers as possible. Knowing the multiplication table up to 10×10, it should be easy to learn by heart whether each number up to 100 is prime or composite.
  2. Pay attention to the last digit. If it is 5, then the number is composite (unless it is =5).
  3. Check whether the sum of the digits is divisible by 3. If it is, then the number is composite (unless it is =3).
  4. If the number is between 100 and 300, check whether the sum of the first and the third digits equals the second digit. If this is true, then the number is divisible by 11, and therefore it is composite. 209 is the only other number in this range divisible by 11.

Good luck playing and let us know if you beat our personal record of 67 points!

Primes between 1 and 300:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97

101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199

211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293

Sneaky composites:

51, 57, 87, 91

119, 133, 161, 169

209, 217, 221, 247, 253, 259, 287, 289, 299

Some Math

Some of you may be wondering why the rules listed above work and whether we can create similar rules for larger numbers. Here are some explanations for the curious among you:

Rule for division by 3

Consider the 5-digit number ABCDE. It can be written as:

ABCDE = 10000A + 1000B + 100C + 10D + E

Since 10000 = 3 × 3333 + 1, 1000 = 3 × 333 + 1, 100 = 3 × 33 + 1, and 10 = 3 × 3 + 1, we can see that:

ABCDE = 3 × (3333A + 333B + 33C + 3D) + (A + B + C + D + E)

Therefore, ABCDE is divisible by 3 if and only if (A + B + C + D + E) is divisible by 3.

Rule for division by 11

Consider again the number ABCDE. Since 10000 = 11 × 909 + 1, 1000 = 11 × 91 – 1, 100 = 9 × 1 + 1, and 10 = 11 – 1, we can see that:

ABCDE = 11 × (909A + 91B + 9C + D) + (A – B + C – D + E)

Therefore, ABCDE is divisible by 11 if and only if (A – B + C – D + E) is divisible by 11.

Rule for division by 7

Once again, consider the number ABCDE. Notice that it can be written as:

ABCDE = 10 × ABCD + E

Now, let us find a number X such that 10X gives remainder 1 when divided by 7. Such number is X = 5. Indeed, 5 × 10 = 50 = 7 × 7 + 1. Therefore, the following statements are equivalent:

  • ABCDE = 10 × ABCD + E is divisible by 7
  • 5 × ABCDE = 49 × ABCD + ABCD + 5E is divisible by 7
  • ABCD – 2E is divisible by 7

Rules for division by 13, 17, 19, etc.

The idea of the rule for division by 7 can be applied to rules for divisions by higher numbers. For example, here is how we can find a rule for division by 13:

  1. Find the smallest positive integer X, so that 10X – 1 is divisible by 13. Such number is X = 4. Note that ABCDE is divisible by 13 if and only if 4 × ABCDE is divisible by 13.
  2. Rewrite 4 × ABCDE as:
    4 × ABCDE = 39 × ABCD + ABCD + 4E
  3. Conclude that ABCDE is divisible by 13 if and only if ABCD + 4E is divisible by 13.

As an exercise, try to deduce a similar rules for division by 17 and 19! Note that for 17, instead of finding X, such that 10X – 1 is divisible by 17, you may get a simpler rule by finding X, such that 10X + 1 is divisible by 17.

For deeper understanding of how division of integers works, we recommend our more enthusiastic readers to look into Modular Arithmetic.

The Puzzle TOAD

The Puzzle TOAD is a website, created by four Carnegie Melon professors (Tom Bohman, PO Shen-Loh, Alan Frieze, Danny Sleator), where you can find a growing collection of ingenious math brain teasers. Unlike Puzzle Prime, The Puzzle Toad is targeted exclusively towards math and computer science majors. Students who are preparing for college Olympiads will find the problems particularly useful. Check out The Puzzle TOAD by clicking the banner below.

Minecraft: Magnetic Travel Puzzle


Minecraft: Magnetic Travel Puzzle (M:MTP for short) is a travel game by ThinkFun in which the goal is to arrange 3 types of objects, each coming in 3 different colors, in a 3 by 3 grid, such that certain conditions are satisfied.

As you progress through the 40 included challenges, the types of conditions you encounter become gradually more complex. While in the beginning you may be given all the colors of the objects with one clue and all the types of the objects with another, later on you need to analyze 5 or 6 clues at once, which makes the game more challenging and fun. That being said, at the hardest levels, M:MTP is still relatively easy, so experienced puzzlers will probably breeze through it within an hour or two.

At its core, M:MTP is identical to ThinkFun’s previously released Clue Master. Both games are presented in the form of magnetic notebooks, so they are easy to pick up and travel around with. The illustrations of the Minecraft edition are all based on the popular video game, so its fans may be particularly appreciative.

If you are looking for a casual puzzle to pass an hour or two on a road trip, then M:MTP would be a great choice. I only wish there were more challenges included, especially more difficult ones.

  • 1 player, 8 years and up
  • 40 challenges with increasing difficulties
  • easy to transport and play on the go
  • cool Minecraft based art
  • most puzzles can be solved with a few simple techniques


* This post contains affiliate links. We may receive a small compensation if you make a purchase.