What the Structure Is For is a free printable Grade 4 science worksheet on how internal and external structures support survival, growth and reproduction, aligned to NGSS performance expectation 4-LS1-1. It prints 2 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two students in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.
Set 21 of 25 · the same problems every time you open this link.
Set 1 has all 25 in a single PDF. All 25 sets ask different questions.
What the Structure Is For
4-LS1-1
NameDate
Draw a line from each structure to what it does.
1.Draw a line from each one to its match.
A skeleton
An owl's large eyes
A bird's hollow bones
A goat's split hooves
A.Keep it light enough to fly
B.Holds the body up and lets it move
C.Gather enough light to hunt at night
D.Grip on steep rocky slopes
2.Draw a line from each one to its match.
A cactus's thick waxy stem
A seed's hard coat
A fish's gills
A heart
A.Protects the tiny plant inside until it sprouts
B.Take in oxygen from the water
C.Stores water and stops it drying out
D.Pumps blood around the body
LessonPrint · 4-LS1-1 · Set 21 · free to copy for classroom use
Answer key — What the Structure Is For
Set 21. Prints on its own sheet.
1.1. A skeleton — B (Holds the body up and lets it move) 2. An owl's large eyes — C (Gather enough light to hunt at night) 3. A bird's hollow bones — A (Keep it light enough to fly) 4. A goat's split hooves — D (Grip on steep rocky slopes)
2.1. A cactus's thick waxy stem — C (Stores water and stops it drying out) 2. A seed's hard coat — A (Protects the tiny plant inside until it sprouts) 3. A fish's gills — B (Take in oxygen from the water) 4. A heart — D (Pumps blood around the body)
Last reviewed 2026-09-05. Aligned to 4-LS1-1 of the Next Generation Science Standards.