The three different ways mammals give birth

All mammals share certain characteristics, like warm blood and backbones. But despite their similarities, these creatures also have many biological differences — and one of the most remarkable differences is how they give birth.

Watch a video and choose the correct answers.

1. What do you call the solid disc of blood rich tissue that is used to feed and oxygenate the embryo inside of animals such as humans, whales, dogs and cats?

a) Uterus
b) Placenta
c) Umbilical cord
d) Ovary

2. Human, cats, dogs and whales are all considered:

a) Placental Mammals
b) Marsupials
c) Monotremes
d) Land mammals

3. When a kangaroo gives birth to her offspring it is the size of a(n) __________ before it first enters her pouch.

a) Ant
b) Jelly bean
c) Baseball
d) Squirrel

4. Monotremes are mammals that lay eggs. The word monotreme literally means:

a) One egg
b) One hole
c) Egg-laying
d) One offspring

5. Other than the platypus, the only other type of monotreme that lives on Earth today are the:

a) Koalas
b) Wallabys
c) Armadillos
d) Echidnas

6. Most of the mammals that exist on Earth today are placental mammals. Name three placental mammals from three different continents that were not mentioned in the video.


The Creators
Educator Kate Slabosky
Director Petya Zlateva
Producer Vessela Dantcheva
Animator Petya Zlateva
Designer Petya Zlateva
Illustrator Petya Zlateva
Sound Designer Alexander Daniel, Alexander Evtimov, Mihail Yosifov
Composer Alexander Daniel, Alexander Evtimov, Mihail Yosifov
Script Editor Emma Bryce

How blood pressure works


Doctor taking patient’s blood pressure

If you lined up all the blood vessels in your body, they’d be 60 thousand miles long. And every day, they carry the equivalent of over two thousand gallons of blood to the body’s tissues. What effect does this pressure have on the walls of the blood vessels?

Watch a video and choose the correct answers.

1. During what phase of the cardiac cycle is blood pressure typically lowest?

a) Coronary
b) Diastole
c) Systole
d) Ventricular
e) Atrial

2. A typical, healthy individual produces a systolic pressure between _____ and _____ millimeters of mercury.

a) 90; 120
b) 60; 80
c) 60; 120
d) 60; 90
e) 40; 60

3. Hypertension occurs when systolic and diastolic blood pressure regularly rises above _____ and _____ millimeters of mercury, respectively.

a) 120; 80
b) 140; 90
c) 80; 60
d) 120; 90
e) 130; 80

4. What condition describes the thickening of the arterial wall due to the decomposition of plaques of fatty material and inflammatory cells?

a) High blood pressure
b) Myocardial infarction
c) Atherosclerosis
d) Angioplasty
e) Hypertension

5. Dangerously-clogged blood vessels can be widened by a procedure called a(n) _____.

a) Sphygmomanometer
b) Angioplasty
c) Ablation
d) Transplant
e) Phlebotomy

6.  How does atherosclerosis develop, and what are its possible long-term consequences?

The Creators
Educator Wilfred Manzano
Director Nick Sazani
Producer Steve Shin, Samantha Scharff, Matthew Chadwick, Arielle Matorana
Editor Leroy Patterson
Script Editor Eleanor Nelsen

How brass instruments work


What gives the trumpet its clarion ring and the tuba its gut shaking oompah-pah? And what makes the trombone so jazzy? Al Cannon shows how these answers lie not in the brass the instruments are made of, but in the journey that air takes from the musician’s lungs to the instrument’s bell.

Watch a video and choose the correct answers.

1. Brass instruments create vibration from _____.

a) Being plucked or bowed
b) Being struck
c) The mouth
d) Air against a reed

2. The escaping air meets resistance from the lip muscles, which forms a hole called the _____, and creates the vibration that brass players call the buzz.

a) Aperture
b) Buzz
c) Spit valve
d) Gap

3. The buzz results from _____.

a) The mouthpiece
b) Lengthening the tubing of the instrument with a valve or slide
c) A balance tension between the lip muscles and air flow
d) Stopping air flow

4. The brass instrument capable of playing the lowest notes is the _____.

a) Tuba
b) Trombone
c) Clarinet
d) Trumpet

5. The harmonic series _____.

a) Contains every pitch on a staff
b) Has pitches occurring consistently far apart from one another
c) Has pitches occurring consistently close to one another
d) Is a limited pattern of pitches

6. Explain how a brass musician can create various pitches with his/her instrument.



The Creators
Educator  Al Cannon
Director  Franz Palomares
Script Editor  Alex Gendler
Composer  Carlos Palomares

The networked beauty of forests


Deforestation causes more greenhouse gas emissions than all trains, planes and automobiles combined. What can we do to change this contributor to global warming? Suzanne Simard examines how the complex, symbiotic networks of our forests mimic our own neural and social networks — and how those connections might make all the difference.

Watch a video and choose the correct answers.

1. Suzanne Simard compares forests to human ________.

a) Arteries
b) Families
c) Social networks
d) Skeletons

2. Deforestation creates more greenhouse gas emissions than all of the trains, planes, and automobiles combined.

a) True
b) False

3. What happens during photosynthesis?

a) Plants consume carbon dioxide
b) Plants release oxygen
c) Plants eat harmful bacteria in the soil
d) Both A and B

4. A single tree can be linked to ________.

a) The heat death of the universe
b) The evolution of homo sapiens
c) Hundreds of other trees
d) Logging companies around the world

5. Under a single footstep in the forest, there are ________.

a) Over 1 billion ants
b) 300 miles of fungal hyphae
c) Enough carbon molecules to start another universe
d) Pounds of animal excrement

6. When you walk through the forest, what you see is just the tip of the iceberg. Why is understanding this important for dealing with global warming?



The Creators
Speaker Suzanne Simmard

Are food preservatives bad for you?


Food doesn’t last. In days, sometimes hours, bread goes moldy, apple slices turn brown, and bacteria multiply in mayonnaise. But you can find all of these foods out on the shelf at the grocery store — hopefully unspoiled — thanks to preservatives. But what exactly are preservatives? How do they help keep food edible? And are they safe?

Watch a video and choose the correct answers.

1. Which of the following causes food to spoil?

a) Funghi
b) Oxidation
c) Bacteria
d) All of the above
e) b) and c) only

2. Which of these compounds wards off microbes by lowering a food’s pH?

a) Smoke
b) Acid
c) Salt
d) Tocopherols

3. Which of the following is/are NOT antioxidants?

a) Propionic acid
b) Sulfites
c) Nitrates
d) a) and b)
e) a) and c)

4. Nitrates defend against _______, but may increase your risk of _______.

a) Botulism/cancer
b) Listeria/hyperactivity
c) Cancer/asthma
d) Oxidation/cancer

5. Which of these can prevent cut produce from browning?

a) Acetic acid
b) Citric acid
c) Vitamin E
d) Salt

6. Describe two primary pathways for food degradation, and name a few preservatives that can combat each.



The Creators
Educator Eleanor Nelsen
Director Dmitry Yagodin
Animator Dmitry Yagodin
Designer Dmitry Yagodin
Producer Vessela Dantcheva
Composer Samuel Pocreau
Sound Designer Samuel Pocreau

The ancient origins of the Olympics


Thousands of years in the making, the Olympics began as part of a religious festival honoring the Greek god Zeus in the rural Greek town of Olympia. But how did it become the greatest show of sporting excellence on earth? Armand D’Angour explains the evolution of the Olympics.

Watch a video and choose the correct answers.

1. What was the date of the first Olympics?

a) 1000 BC
b) 776 BC
c) 1066 AD

2. What ancient place name underlies the word Olympics?

a) Olympus
b) Olbia
c) Olympia

3. What was the first event in the ancient Olympics?

a) Wrestling
b) Running
c) Jumping

4. Which Roman emperor banned the Olympics?

a) Nero
b) Diocletian
c) Theodosius

5. What was the profession of the first winner of the ancient Olympics?

a) Baker
b) Blacksmith
c) Philosopher

6. What main differences are there between the ancient and modern Olympics?


7. The Olympics are held only every four years. What is the history behind this schedule?


The Creators
Educator Armand D’Angour
Director Diogo Viegas
Artist Marcelo Vaz
Animator Leonardo Bentolila, João Machay
Editor Alessandro Monnerat
Script Editor Amy Adkins
Composer Cem Misirlioglu, Brooks Ball

Football physics: The “impossible” free kick


In 1997, Brazilian football player Roberto Carlos set up for a 35 meter free kick with no direct line to the goal. Carlos’s shot sent the ball flying wide of the players, but just before going out of bounds it hooked to the left and soared into the net. How did he do it? Erez Garty describes the physics behind one of the most magnificent goals in the history of football.

Watch a video and choose the correct answers.

1. Which physics principal underlies the banana kick?

a) Newton’s first law of motion
b) Ballistic movement
c) The Magnus effect
d) The Maxwell effect

2. What causes the ball to curve?

a) Air pressure
b) Momentum
c) Gravity
d) Friction

3. Who described first the Magnus effect?

a) Roberto Carlos
b) Sir Isaac Newton
c) The ancient Greek
d) Heinrich Gustav Magnus

4. Can a soccer ball be boomeranged back to the player?

a) Yes, but it will take a very precise and strong kick
b) No, because the force needed for the kick is too high
c) Yes, but only in space
d) No, because the ball will swirl in smaller and smaller circles

5. In which of these sports can one not observe the Magnus effect?

a) Baseball
b) Tennis
c) Basketball
d) Skiing

6. Can a banana kick be performed on the moon?


The Creators
Educator Erez Garty
Director Hector Herrera
Producer Pazit Cahlon
Sound Designer Nick Sewell