MS-LS1-5: How Genes and Environment Shape Growth
Also called NGSS MS-LS1-5 · Topic: Growth, Development, and Reproduction of Organisms · Life Science
The Official Wording
Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms.
Clarification statement: Examples of local environmental conditions could include availability of food, light, space, and water. Examples of genetic factors could include large breed cattle and species of grass affecting growth of organisms. Examples of evidence could include drought decreasing plant growth, fertilizer increasing plant growth, different varieties of plant seeds growing at different rates in different conditions, and fish growing larger in large ponds than they do in small ponds.
Assessment boundary: Assessment does not include genetic mechanisms, gene regulation, or biochemical processes.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What MS-LS1-5 Means in Plain English
Middle schoolers explain, with evidence, why organisms of one kind grow to different sizes. Some causes come from inherited traits, like a variety bred to stay short. Others come from surroundings, like the food, light, water and space each organism gets.
Students compare outcomes but do not study how genes work inside cells or the chemistry of growth. This builds on what plants need (5-LS1-1) and leads to how traits are passed on (MS-LS3-2) and how mutations change them (MS-LS3-1).
MS-LS1-5 I Can Statements
- I can name environmental factors that affect how an organism grows.
- I can name genetic factors that affect how an organism grows.
- I can use data to tell which kind of factor caused a difference.
MS-LS1-5 Worked Example
A four-week sunflower test that changes one inherited factor and one environmental factor.
Which matters more for sunflower height, the seed variety or the size of the pot?
Set It Up: Seeds of a dwarf and a giant sunflower variety, 8 small yogurt cups, 8 big pots, potting soil and a ruler.
- Plant 4 dwarf and 4 giant seeds in cups, and the same in big pots.4 groups of 4 plants
- Give every plant the same window, the same soil and the same water.Only variety and pot differ
- Measure each stem from soil to tip every week.Height in cm, weeks 1 to 4
- Average each group at week 4.Giant big pot 32, giant cup 19, dwarf big pot 14, dwarf cup 9
Giant seeds grew taller than dwarf seeds in both pot sizes, and every variety grew taller in a big pot than in a cup.
Why it works: Genes set the range a plant can grow within, and conditions like root space decide where in that range it ends up.
Common Mistakes with MS-LS1-5
Picking only one cause
“It's all genes” or “It's all the soil.”
Try this: Look at both factors in the data. Here variety and pot size each changed height, so both genes and environment matter.
Changing everything at once
Giant seeds in big pots, dwarf seeds in cups only
Try this: Test every variety in every condition, otherwise you cannot tell whether the seed or the pot caused the difference.
Thinking a better home changes the genes
“The dwarf grew big, so its babies will be big.”
Try this: Better conditions help one plant grow, but they do not change the genes its seeds inherit, so offspring start from the same range.
Where MS-LS1-5 Fits
Practice MS-LS1-5
Quick Check
- Identical twin calves get very different amounts of food. Which factor explains their size difference?
- Two kinds of grass get the same sun and water, but one grows taller. Why?
- Why does a drought make crops smaller?