Students who demonstrate understanding can: 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.
Official wording from the Next Generation Science Standards (NGSS Lead States, 2013). NGSS is a registered trademark of WestEd. Neither WestEd nor the lead states and partners that developed the NGSS were involved in the production of this page, and they do not endorse it. View on nextgenscience.org
How big a plant or animal grows depends on two things working together: the traits it inherits and the conditions it lives in. Genetic factors set the possible range. A large-breed cattle variety has the potential to grow heavier than a small breed, and different grass species grow at different rates. Environmental factors, such as food, light, water and space, decide how much of that potential is reached.
Students build explanations from evidence. Classic data sets include tomato plants given different amounts of fertilizer, bean plants grown in light and in darkness, crops during drought years, or the same species of fish growing larger in a big pond than a small one. A strong explanation names the factor, uses the data to show its effect, and identifies whether the factor is genetic or environmental.
The point is not to pick one cause. Two seeds from the same parent can grow very differently in poor and rich soil, and two varieties in the same soil can still differ, so growth is a result of both.
Students often say an organism's size is fixed at birth. Twin plants grown in rich and poor soil quickly show that the environment changes how much an organism grows.
Past a certain amount, extra fertilizer or water can harm plants. Data sets often show growth rising and then leveling off or falling.
A well-fed calf grows larger, but its genes are unchanged and it does not pass the larger size on because of the food it ate.
Two groups of bean plants from the same seed packet were grown for 14 days with the same water and soil. Group A got 12 hours of light a day and grew to an average of 18 cm. Group B got 4 hours of light and grew to 9 cm. Explain the results.
Answer: More light (an environmental factor) caused greater growth, 18 cm compared with 9 cm, because the plants could make more food; genes were kept similar by using seeds from one packet.
Fast-growing plants such as radishes or beans let students run their own fair test within two weeks. Assign different groups different variables, such as light, water, fertilizer or crowding, and pool the data so the class sees several environmental factors at once.
Include at least one comparison of varieties grown side by side to bring in genetic factors. Assessment excludes gene mechanisms, so keep the genetic side at the level of 'different varieties or breeds have different growth potential'.
Original questions written for this standard. Choose an option or type your answer, then press Check. Every question has a worked explanation.
Answer: B) Breed of cattle
The breed is inherited, so it is a genetic factor. Light, rainfall and pond size are environmental.
Answer: C) More space and food in the big pond allow more growth
The species is the same, so the difference comes from the environment, such as more space and food.
Answer: water
A drought is a long period with little rain, so water is scarce and plant growth slows.
Answer: A) Environment can affect growth even when genes are the same
With the same genes, the difference must come from the environment, here the soil nutrients.
Answer: B) Light, water and plant variety
In a fair test only the fertilizer changes; light, water and variety are controlled.
Answer: environmental (also accepted: environment, an environmental factor)
Light comes from the surroundings, so it is environmental.
Use evidence to support the explanation that traits can be influenced by the environment.
Support an argument that plants get the materials they need for growth chiefly from air and water.
A full lesson with slides, activities and an exit ticket on genes, environment and growth, pitched to grades 6-8 and editable in PowerPoint or Google Slides.
Make a lesson βA printable, differentiated worksheet on MS-LS1-5 with an answer key, ready in about a minute.
Make a worksheet βTurn genes, environment and growth into a quiz students answer online that marks itself, with a class summary for you.
Build a test βData such as drought reducing plant growth, fertilizer increasing it, seed varieties growing at different rates, or fish growing larger in larger ponds.
No. The assessment boundary excludes genetic mechanisms, gene regulation and biochemical processes.