Inside the Cell
Body Systems
Genetics & Heredity
Weird Science Facts
The Animal Kingdom
100

Famously known as the "powerhouse of the cell," this organelle generates chemical energy.

A: What is the mitochondria?

100

This system acts as your body's structural framework, containing exactly 206 bones in an adult.

A: What is the skeletal system?

100

This twisted, ladder-shaped molecule carries all the genetic instructions for building a living thing.

A: What is DNA?

100

Human teeth are incredibly strong, matching the exact hardness level of this apex ocean predator's teeth.

A: What is a shark?

100

Animals like frogs and toads that can live both underwater using gills and on land using lungs belong to this group.

A: What are amphibians?

200

Acting like the cell's brain or control tower, this large organelle holds all the cell's DNA.

A: What is the nucleus?

200

This muscular pump beats roughly 100,000 times a day to push blood through your body.

A: What is the heart?

200

This type of genetic trait will always show up in an offspring if even one copy is passed down from a parent.

A: What is a dominant trait?

200

This is the only mammal capable of true, sustained flapping flight (no, flying squirrels just glide!).

A: What is a bat?

200

This term describes how an animal structurally or behaviorally changes over time to better survive in its environment (like a polar bear's white fur).

A: What is an adaptation?

300

Plant cells have these two unique structures that animal cells completely lack.

A: What are the cell wall and chloroplasts?

300

Your skin belongs to this oddly-named body system, which serves as your first line of defense.

A: What is the integumentary system (or skin system)?

300

If a scientist describes your physical appearance (like having blue eyes), they are talking about this "P-word."

A: What is a phenotype?

300

Water is weird because its solid form (ice) does this when placed in its liquid form.

A: What is floats?

300

This type of deep winter sleep allows animals like bears and groundhogs to conserve energy when food is scarce.

A: What is hibernation?

400

This jelly-like fluid fills the empty spaces inside a cell and holds all the organelles in place.

A: What is cytoplasm?

400

These tiny, microscopic air sacs in your lungs are where oxygen actually enters your bloodstream.

A: What are alveoli?

400

Gregor Mendel famously discovered the laws of genetics in the 1860s by breeding generations of this vegetable.

A: What are pea plants?

400

Despite having no brain, no bones, and no heart, this gelatinous ocean creature has survived on Earth for over 500 million years.

A: What is jellyfish?

400

This active defense mechanism is used by animals like cuttlefish and chameleons to blend seamlessly into their surroundings.

A: What is camouflage?

500

This selectively permeable barrier surrounds all cells, acting like a security guard that controls what goes in and out.

A: What is the cell membrane?

500

These elastic bands of tissue connect your bones to other bones at a joint (not to be confused with tendons!).

A: What are ligaments?

500

This grid-like diagram is used in biology to predict all the possible genetic outcomes of a cross between two parents.

A: What is a Punnett square?

500

This organ is the largest internal organ in the human body and is responsible for filtering toxins out of your blood.

A: What is the liver?

500

Unlike mammals, these cold-blooded vertebrates have dry scales, lay amniotic eggs on land, and include lizards and snakes.

A: What are reptiles?