MS-LS1-5: How Environmental and Genetic Factors Affect Growth
In plain English: MS-LS1-5 is the NGSS middle school performance expectation that asks students to construct an explanation, based on evidence, of how environmental factors such as food, light, space and water, and genetic factors such as breed, species or variety, influence how organisms grow. Students compare growth data from plants and animals. It is usually taught in grade 6, 7 or 8 life science.
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.
Next Generation Science Standards · Disciplinary Core Idea: From Molecules to Organisms: Structures and Processes · Official standard
Students construct explanations, backed by evidence, of how environmental factors (food, light, space and water) and genetic factors (the breed, species or variety an organism inherits) affect growth. They learn to separate the two: compare organisms with the same inherited traits in different surroundings to see an environmental factor, and organisms with different inherited traits in the same surroundings to see a genetic factor. The evidence includes drought, fertilizer, crowding, pond size, cattle breeds, grass species and crop varieties. All data sets on this page are invented for teaching.
The NGSS Clarification Statement says: "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." The Assessment Boundary says: "Assessment does not include genetic mechanisms, gene regulation, or biochemical processes." So no item on this page asks how genes work or what happens inside cells; a genetic factor is always shown by comparing breeds, species or varieties. Students do the practice of constructing explanations: they analyze data, decide which factor caused a difference and write a claim with evidence and reasoning.
Learning Objectives
By the end of this lesson, students will be able to:
Tell environmental factors (food, light, space, water) apart from genetic factors (breed, species, variety) that affect growth
Use data to show how drought, fertilizer, crowding and pond size change the growth of one kind of organism
Use data from different breeds, species or varieties in the same surroundings to show a genetic factor
Construct an explanation, with a claim, evidence and reasoning, for data in which both kinds of factors act
Prior Knowledge Required
Students should already be comfortable with:
Traits are inherited from parents and vary within a group 3-LS3-1
Traits can be influenced by the environment 3-LS3-2
What plants need to grow: light, air, water and nutrients
Comparing quantities with differences, ratios and percents 6.RP.A.3
Show two photos or drawings: a Shetland pony foal and a draft horse foal grazing in the same field, and two pumpkins of the same kind, one from a garden with rich, watered soil and one from a dry, crowded patch.
Warm-Up Prompt
"In each pair, one is much bigger than the other. For each pair, what do you think made the difference: something the organism got from its parents, something in its surroundings, or both? What would you need to know to be sure?"
Sort student ideas into two columns on the board: "from the parents" and "from the surroundings". Keep the list: it becomes the two kinds of factors in the lesson.
Direct Instruction15-20 minutes
Key words.Growth is an increase in an organism's size or mass (how much matter it has). A factor is anything that can change a result. Environmental factors come from the surroundings: food, light, space and water, for example. Genetic factors are inherited: they are passed from parents to offspring, such as the breed of a cow, the species of a grass or the variety of a crop. A breed is a group of animals within one species, and a variety is a group of plants within one species, that people have bred to share certain traits. Fertilizer adds nutrients (materials plants need from the soil), and a drought is a long period with too little water. How genes work inside cells is beyond this standard: students only compare organisms with different parents or with different surroundings.
How to separate the two kinds of factors. To show an environmental factor, compare organisms with the same inherited traits (one breed, variety or species) in different surroundings. To show a genetic factor, compare organisms with different inherited traits in the same surroundings. All data on this page are invented for teaching.
Genetic factor: species of grass
Pampas grass and blue fescue are both grasses. A gardener plants them side by side in one bed, with the same soil, water and sunlight. After two summers the pampas grass clumps are 2.5 m tall and the blue fescue clumps are 0.25 m tall.
Result: 2.5 ÷ 0.25 = 10, so the pampas grass is 10 times as tall. The surroundings were the same, so the difference comes from the species, a genetic factor.
Environmental factor: drought decreases growth
20 tomato plants of one variety grow in the same greenhouse. Ten get 1 L of water every 2 days and ten get 0.25 L every 2 days, like a drought. After 4 weeks their average heights are 42 cm and 24 cm.
Result: 42 - 24 = 18 cm shorter, and 24 ÷ 42 ≈ 0.57, so the dry plants reached only about 57% of the height. Same variety, different water: an environmental factor.
Environmental factor: fertilizer increases growth, up to a point
Four trays of bok choy (one variety) get no fertilizer, half the label amount, the full label amount or double the label amount. After 5 weeks the average mass per plant is 18 g, 34 g, 52 g and 49 g.
Result: The full amount gives 52 - 18 = 34 g more than none. Doubling it gives 49 g, no better than the full amount, so more fertilizer stops helping and too much can even harm the roots.
Environmental factor: fish grow larger in large ponds
A farmer stocks 200 young tilapia (one species, from one hatchery) in a 0.1 hectare pond and 200 in a 1.0 hectare pond. Neither pond gets extra feed. After 2 years the fish average 11 cm long in the small pond and 17 cm in the large pond.
Result: Fish per hectare: 200 ÷ 0.1 = 2,000 and 200 ÷ 1.0 = 200, so the small pond is 10 times as crowded. Each fish has less food and space there, so the fish grow 6 cm less.
Both factors: plant varieties grow at different rates in different conditions
Two sorghum varieties, Tall Red and Desert Short, are planted on one farm in a watered field and in a dry field. After 12 weeks: Tall Red 2.4 m (watered) and 1.2 m (dry); Desert Short 1.6 m (watered) and 1.4 m (dry). See Diagram 1.
Result: Tall Red loses 1.2 m in the dry field (half its height) while Desert Short loses only 0.2 m. Tall Red is the better choice where water is plentiful, and Desert Short is the better choice in a drought.
After each example, ask: "What stayed the same? What was different? Is the different thing inherited or from the surroundings?" Point out that the sorghum example needs both kinds of factors to explain it.
Guided Practice10-15 minutes
Pairs analyze invented data from a farm study of cattle. Angus is a common full-size beef breed and Dexter is a small breed. Steers (young male cattle) of each breed grazed on a good pasture with plenty of grass or on a poor, overgrazed pasture with little grass, 8 steers per group. Diagram 2 shows the same data.
Guided practice data (invented): mean mass at 12 months
Breed
Good pasture (kg)
Poor pasture (kg)
Angus
390
300
Dexter
220
170
Which two numbers would you compare to see the effect of the breed (a genetic factor)? Compare them on each pasture.
Which two numbers show the effect of the pasture (food, an environmental factor)? Compare them for each breed.
Does good pasture add the same number of kilograms for both breeds? What might explain the difference?
Write an explanation: "Both ___ and ___ affect how large a steer grows. Evidence: ___. Reasoning: ___."
Independent Practice10-15 minutes
Each student writes an explanation from a new invented data set about light. A student cut 12 stems (cuttings) from one mint plant, so all of them have the same inherited traits. She rooted them in water and planted them in identical pots of the same soil. Six pots sat in a sunny window and six in a dim corner of the room, and all got the same water.
Independent practice data (invented): mint cuttings after 4 weeks, mean per plant
Location
Mass (g)
Number of leaves
Sunny window
14.0
38
Dim corner
6.5
16
Students compare the two groups, explain why using cuttings from one plant matters, and write a claim, evidence and reasoning paragraph about how light affects growth. Ask them to name one thing that could still differ between the window and the corner, besides light.
Closure5 minutes
Exit ticket: "Give one example of an environmental factor and one example of a genetic factor that affect growth. For each, describe the comparison that would show its effect." Return to the warm-up columns and ask which pair, the foals or the pumpkins, shows a genetic factor and how the class could check.
Differentiation Strategies
For Struggling Students
Give a two-column organizer, "What stayed the same?" and "What was different?", for every data set before naming the factor
Provide the sentence frame: "The ___ were the same, so the difference in growth comes from ___, which is a ___ factor."
Start with the tomato drought example and the mint cuttings, where only one thing changes, before the two-factor cattle data
For Advanced Students
Ask students to explain why good pasture added more kilograms to Angus than to Dexter steers
Have students design a 2 by 2 investigation (two varieties, two conditions) and predict what an interaction would look like on a bar graph
Ask students to find a weakness in the island deer comparison and propose evidence that would separate the two kinds of factors
Assessment Guidance
What to Look For
Check that students name what stayed the same before naming the factor, and that they do not call a breed or variety an environmental factor. Look for explanations that cite numbers from both groups and say how the factor reached the organism (less water, more nutrients, less food per fish). Listen for students who think one kind of factor rules out the other, or who stray into how genes work, which this standard leaves out.
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Classroom Activities
3 Activities
1
Grass Cups: Species and Water
15 min setup, 5 min checks over 12 daysGroups of 4
Groups grow two species of grass, oats and annual ryegrass, in cups that are kept moist or watered only every 4 days. The design tests a genetic factor (species) and an environmental factor (water) at the same time.
Procedure
Fill 4 clear plastic cups with the same potting soil. Sow 20 oat seeds in two cups and 1 teaspoon of ryegrass seed in the other two, and cover the seeds with a thin layer of soil.
Label one cup of each species "moist" (water with 20 mL every day) and one "dry" (20 mL every 4 days). Keep all cups on the same sunny windowsill.
On day 12, measure the 10 tallest blades in each cup to the nearest 0.1 cm and find the mean.
Safety: wash hands after handling soil and seeds, and do not eat the seeds.
Sample Data (invented)
Mean height of the 10 tallest blades on day 12: oats moist 14.2 cm, oats dry 8.6 cm, ryegrass moist 10.4 cm, ryegrass dry 5.1 cm.
Discussion Questions
In the sample data, oats grew taller than ryegrass in both water conditions. Which kind of factor does that show, and how do you know?
The dry cups were shorter for both species. How many centimeters did the dry condition take away from each species?
Why do all four cups sit on the same windowsill and use the same soil?
Modification for Distance Learning
Students plant the cups at home with grass seed from a garden store, post photos with a ruler on day 6 and day 12, and enter their means in a shared class table.
2
Crowded Cups: Space and Growth
15 min setup, 15 min harvest after 5 weeksPairs
Pairs sow marigold seeds in identical cups at three crowding levels, 1, 4 or 16 seedlings per cup, and after 5 weeks compare the mass of the plants. Space is the environmental factor; all seeds come from one packet of one variety.
Procedure
Use three 300 mL cups with drainage holes and the same soil. Sow extra seeds, then pull out seedlings after one week so the cups hold exactly 1, 4 and 16 plants.
Give every cup the same water on the same days and keep them side by side under the same light.
After 5 weeks, cut every plant at the soil line with blunt scissors, weigh all plants from each cup together on a kitchen scale, and divide by the number of plants.
Sample Data (invented)
Total mass per cup: 1 plant, 6.0 g; 4 plants, 12.8 g; 16 plants, 19.2 g.
Discussion Questions
The total mass in the cup went up as more plants were added, but the mass per plant went down. Find the mass per plant for each cup and explain both patterns.
Which resources do crowded plants share? Name at least two.
How is this cup like the small pond with 2,000 tilapia per hectare?
Challenge Variation
Pairs add a fourth cup with 16 plants and double the water. They predict whether the mass per plant will rise and test whether water or space limits these crowded plants.
3
Genes or Environment? Evidence Card Sort
20 minGroups of 3-4
Groups sort 8 evidence cards into three piles: genetic factor, environmental factor, or both. For each card they write one sentence that names what stayed the same and what was different. Then each group writes one explanation that uses at least one card from each pile.
The 8 Cards (invented data)
Card 1: Great Dane and beagle puppies eat the same food in one kennel. At 6 months they weigh 40 kg and 8 kg.
Card 2: Strawberry runners from one plant (identical inherited traits) grow in sandy soil or in rich garden soil. After 8 weeks they have 9 and 21 leaves.
Card 3: Chicks of a meat breed and an egg-laying breed eat the same feed. At 6 weeks they weigh 2.6 kg and 0.5 kg.
Card 4: Pumpkin plants of one variety grow in a sunny field or a shaded field. Their vines reach 4.0 m and 2.2 m.
Card 5: Two corn varieties grow in the same field with the same care. They reach 2.6 m and 1.8 m.
Card 6: Goats of one breed get extra hay all winter or no extra hay. By spring the young goats weigh 32 kg and 26 kg.
Card 7: Rainbow trout from one hatchery batch are released into a stream full of insects and a stream with few insects. At age 3 they are 25 cm and 16 cm long.
Card 8: Holstein (a large dairy breed) and Jersey (a small dairy breed) heifers, half of each breed on extra feed. At 15 months: Holstein 420 kg with extra feed and 360 kg without; Jersey 300 kg with extra feed and 260 kg without.
Discussion Questions
Exactly three cards show only a genetic factor. Which are they, and what stayed the same in each?
Card 8 is the only card that shows both factors. What two comparisons can you make inside it?
Card 4 says the pumpkins are "one variety". Why does the card need to say that?
Modification for Distance Learning
Put the cards on a shared slide with three drop zones. Groups drag each card into a zone and type their sentence under it.
03
Diagrams & Visual Aids
2 diagrams
Diagram 1: Two Sorghum Varieties in Watered and Dry Fields
Invented field-trial data from the worked examples, drawn to scale. Tall Red grows taller than Desert Short in the watered field, but Desert Short grows taller in the dry field. Variety is a genetic factor and water is an environmental factor, and the effect of one depends on the other.
Diagram 2: Breed and Pasture Both Affect Steer Mass
The invented guided-practice data, drawn to scale. On either pasture, Angus steers are heavier than Dexter steers (a genetic factor). For either breed, steers on good pasture are heavier than on poor pasture (an environmental factor: food).
04
Homework Assignment
~30 min
MS-LS1-5 Homework: Explaining Growth With Evidence
Directions: All data sets are invented for practice. Show each calculation. Then write an explanation that names the factor (environmental, genetic or both), cites numbers as evidence and explains how the factor affected growth.
Part 1: Environmental Factors (Problems 1-3)
Twenty pepper seedlings of one variety grow under grow lights. Ten get 16 hours of light a day and ten get 8 hours. After 5 weeks their average mass is 24 g and 11 g. (a) Find the difference in mass, and about how many times as heavy the 16-hour plants are. (b) Name three things that must be the same for both groups. (c) Write an explanation of how light affected growth.
White-tailed deer on a small island with little food are compared with deer of the same species on the nearby mainland. Yearling males weigh 45 kg on average on the island and 60 kg on the mainland. (a) By what percent are the island deer lighter? (b) A student says the island deer may simply have different parents. Explain why that matters. (c) Fawns from the island raised on a farm with plenty of food grew to 58 kg. What does this new evidence show?
Pumpkin plants of one variety were grown four ways. Average vine length after 10 weeks: watered with fertilizer 3.2 m, watered without fertilizer 2.4 m, dry with fertilizer 1.3 m, dry without fertilizer 1.1 m. (a) How much did fertilizer add with water? Without enough water? (b) Explain why fertilizer helped much more when the plants had water.
Part 2: Genetic Factors and Both Together (Problems 4-6)
Flemish Giant rabbits are a large breed and Netherland Dwarf rabbits are a small breed. Raised on the same food, they weigh 5.5 kg and 0.9 kg at 6 months. A Flemish Giant that was underfed weighed 3.6 kg at 6 months. (a) About how many times as heavy is the well-fed Flemish Giant as the dwarf? (b) Which factor explains that difference? (c) Use both factors to explain the underfed Flemish Giant.
Two potato varieties were grown in a cool summer and in a hot summer on the same farm. Potatoes per plant: Variety A, 1.8 kg (cool) and 0.9 kg (hot); Variety B, 1.4 kg (cool) and 1.2 kg (hot). (a) Find how much each variety lost in the hot summer. (b) Which variety would you plant where summers are hot? (c) Explain how both genetic and environmental factors show up in these data.
Plan an investigation to test whether pot size (space for roots) affects the growth of zinnia plants. (a) Name the factor you change and three pot sizes you would use. (b) List what you keep the same, including how you make sure inherited traits are as alike as possible. (c) Describe what you would measure and how you would make the results reliable. (d) Predict the result and explain your prediction.
Rubric
Criterion
Full Credit (2 pts)
Partial Credit (1 pt)
Using the Data
Correct differences, ratios or percents with units, for every comparison asked
Most calculations correct, or units missing
Naming the Factor
Correctly says whether each comparison shows an environmental factor, a genetic factor or both, and why
Names the factor but does not say what stayed the same
Explanation
Claim, evidence and reasoning that explain how the factor changed growth (food, light, space or water reaching the organism, or inherited size)
Claim and evidence given, but the reasoning is missing or only restates the data
05
Quiz: 20 Questions
Interactive, with answers
Instructions
All data sets are invented. For each comparison, ask what stayed the same and what was different. Your score updates as you answer, and Reset quiz clears everything so you or your students can try again.
Multiple choice: pick an option to check it. Short answer: write your answer, then reveal the model answer.
0 of 20 answered · 0 correct
Question 1 of 20 · Multiple Choice
Which of these is a genetic factor that affects how large a calf grows?
Answer: B
Breed is inherited from the parents, so it is a genetic factor. Choices A, C and D are all conditions in the calf's surroundings: food, space and water are environmental factors.
Question 2 of 20 · Multiple Choice
Which of these is an environmental factor that affects the growth of a tomato plant?
Answer: D
Light comes from the surroundings, so it is an environmental factor. Choices A, B and C all describe what the plant inherited from its parent plants.
Question 3 of 20 · Multiple Choice
Invented data: well-watered corn seedlings averaged 50 cm tall, and seedlings of the same variety in drought conditions averaged 35 cm. By what percent was growth lower in the drought?
Answer: C
The drop is 50 - 35 = 15 cm, and 15 ÷ 50 = 0.30, so growth was 30% lower. Choice A writes the 15 cm difference as a percent. Choice B divides 15 by 35 instead of by the watered height. Choice D is 35 ÷ 50, the height the drought plants reached, not the drop.
Question 4 of 20 · Multiple Choice
Two Angus calves have the same parents. One grows up on a lush pasture and weighs 380 kg at one year. The other grows up on a dry pasture and weighs 290 kg. What best explains the difference?
Answer: A
The calves share their parents and breed, so their inherited traits are as alike as possible; the pasture (food) is the difference. Choices B and C point to genetic factors, but the calves have the same breed and parents. Choice D contradicts the question, since both were weighed at one year.
Question 5 of 20 · Multiple Choice
A Shetland pony foal and a draft horse foal graze on the same pasture and get the same care. At one year, the draft foal is more than twice as heavy. What explains most of the difference?
Answer: B
The surroundings are the same, so the difference comes from what the foals inherited: their breeds. Choices A, C and D name environmental factors, but the question says the pasture and care were the same.
Question 6 of 20 · Multiple Choice
Invented data, grain per plot: Variety M gave 30 kg in a wet year and 10 kg in a dry year. Variety N gave 22 kg in the wet year and 18 kg in the dry year. Which conclusion do the data support?
Answer: C
M gives more grain in the wet year (30 against 22), but N gives more in the dry year (18 against 10), so the better variety depends on the environment. Choice A ignores the dry year. Choice D is backward: M lost 20 kg and N lost only 4 kg.
Question 7 of 20 · Multiple Choice
One fish farm puts 300 young catfish in a 0.5 hectare pond and 300 in a 2 hectare pond. How many times as crowded is the small pond?
Answer: A
Fish per hectare: 300 ÷ 0.5 = 600 and 300 ÷ 2 = 150, and 600 ÷ 150 = 4. Choice B subtracts the pond areas (2 - 0.5 = 1.5). Choice C divides the wrong way (150 ÷ 600).
Question 8 of 20 · Multiple Choice
Invented data: kale plants given no fertilizer, half the label amount, the full amount or double the amount had average masses of 30 g, 45 g, 60 g and 58 g. Which conclusion fits the data?
Answer: D
Mass rises from 30 g to 60 g as fertilizer goes from none to the full amount, but double the amount gives 58 g, no gain. Choice B ignores the last result. Choice C is wrong because 45 g is less than 60 g.
Question 9 of 20 · Multiple Choice
A student wants to show that two wheat varieties differ in how fast they grow because of what they inherited. What should the investigation do?
Answer: B
Keeping the environment the same means any difference in growth comes from the varieties. Choices A, C and D change the environment along with the variety, so the cause would be unclear.
Question 10 of 20 · Multiple Choice
Why might a student use cuttings from a single plant to test how light affects growth?
Answer: C
Cuttings from one plant have the same inherited traits, so a difference in growth can be traced to the light. Choice D would make the test pointless. Choices A and B are not true and do not explain the design.
Question 11 of 20 · Multiple Choice
A student says a prize pumpkin grew huge only because of fertilizer. Which evidence would show that a genetic factor also mattered?
Answer: A
If a different variety grew much smaller with the same care, the inherited variety made a difference too. Choices B, C and D are all environmental factors, so they do not show a genetic one.
Question 12 of 20 · Multiple Choice
A carrot grown alone weighs 70 g. Ten carrots crowded into the same amount of space weigh 200 g in all. How many times as heavy is the carrot grown alone as one crowded carrot?
Answer: D
Each crowded carrot weighs 200 ÷ 10 = 20 g, and 70 ÷ 20 = 3.5. Choice A divides the total crowded mass by the single carrot (200 ÷ 70 ≈ 2.9). Choice B uses the number of carrots. Choice C divides 70 by 200.
Question 13 of 20 · Multiple Choice
Which observation is evidence that drought decreases plant growth?
Answer: B
The same variety, in a dry year compared with a normal one, isolates water as the factor. Choice C shows a genetic factor, not drought. Choices A and D compare other conditions that have nothing to do with water.
Question 14 of 20 · Multiple Choice
Which evidence best shows that a genetic factor affects growth?
Answer: C
When two breeds share the same food and care but grow to different sizes, the difference is inherited. Choices A and B change the environment for a single breed. Choice D shows a season effect on both breeds.
Question 15 of 20 · Short Answer
Invented data: Swiss chard plants of one variety averaged 40 g with no fertilizer and 65 g with the full label amount. Find the increase in grams and as a percent, and name the kind of factor.
The increase is 65 - 40 = 25 g, and 25 ÷ 40 = 62.5%. Fertilizer is an environmental factor: it adds nutrients to the soil, and the plants were all one variety.
Question 16 of 20 · Short Answer
A tall sunflower variety grown in poor, dry soil reached 1.5 m, the same height as a short variety grown in rich, watered soil. Explain how both kinds of factors can give the same result.
The tall variety inherited the ability to grow tall, but poor soil and little water limited it. The short variety inherited a smaller size, but good soil and water let it reach the most it could. So a genetic advantage was cancelled by a poor environment, and a genetic limit was helped by a good one. To see the genetic factor alone, grow both in the same soil.
Question 17 of 20 · Short Answer
A student wants to know whether water or fertilizer matters more for basil growth. Plan an investigation: name the groups, what stays the same and what you measure.
Four groups of basil from one seed packet: water + fertilizer, water only, little water + fertilizer, little water only, with at least 5 plants per group. Keep the same: pot size, soil, light, temperature, planting day. Measure the mass (or height and leaf count) after several weeks and compare the effect of each factor. A full answer explains how repeated plants make the result reliable.
Question 18 of 20 · Short Answer
Invented data: 300 young black crappie were stocked in a 0.4 hectare pond and 300 in a 2 hectare lake. At age 3 the crappie averaged 14 cm in the pond and 21 cm in the lake. Find the fish per hectare in each place and explain the difference in length.
Pond: 300 ÷ 0.4 = 750 fish per hectare. Lake: 300 ÷ 2 = 150 fish per hectare, so the pond is 5 times as crowded. The crappie are one species, so the 7 cm difference (50% longer in the lake) comes from the environment: each fish in the lake has more food and space.
Question 19 of 20 · Short Answer
Invented data, plant height: pepper Variety P reached 48 cm in a warm greenhouse and 30 cm in a cool one. Variety Q reached 40 cm (warm) and 36 cm (cool). Which variety grows taller in each greenhouse, and what does that show?
Warm: P is taller (48 against 40 cm). Cool: Q is taller (36 against 30 cm). P loses 18 cm in the cool greenhouse and Q loses only 4 cm. The varieties differ genetically, and which one grows more depends on the temperature, so both kinds of factors affect growth.
Question 20 of 20 · Short Answer
A student writes: "Tall parents always have tall children, so the environment does not matter for how tall you grow." Use evidence from this lesson to correct the statement.
Inherited traits set what an organism can grow to, but the environment changes how much of that it reaches. Evidence: Angus steers on poor pasture were 90 kg lighter than Angus steers on good pasture (same breed), and mint cuttings from one plant grew much less in dim light. A better statement: "Both inherited traits and the environment affect growth."
0 of 20 answered · 0 correct
06
Frequently Asked Questions
10 Questions
What does MS-LS1-5 mean?
MS-LS1-5 asks students to build an explanation, using evidence, of how the environment and inherited (genetic) factors affect how organisms grow. Students compare plants or animals that differ in their surroundings or in their breed, species or variety. The code means Middle School, Life Science, core idea 1 (From Molecules to Organisms: Structures and Processes), performance expectation 5.
What is the assessment boundary for MS-LS1-5?
The official Assessment Boundary says: "Assessment does not include genetic mechanisms, gene regulation, or biochemical processes." Students do not need to explain how genes work or what happens inside cells. They show a genetic factor by comparing breeds, species or varieties in the same surroundings.
What is the difference between environmental and genetic factors?
Environmental factors come from the surroundings, such as food, light, space and water. Genetic factors are inherited from the parents, such as the breed of a dog or the variety of a crop. A big dog breed on poor food and a small breed on good food can end up closer in size than their breeds alone would predict.
What grade is MS-LS1-5 taught in?
It is a middle school standard for grades 6-8, usually taught in grade 6, 7 or 8 life science. It fits a unit on plant and animal growth and pairs well with plant-growing labs in the spring.
How do you set up a fair plant growth investigation?
Change one factor and keep the rest the same. To test water, use one variety and the same pots, soil and light, and change only the water. Use several plants per group, measure on the same day and record the mean. Fast, safe choices are oats, ryegrass and marigolds.
How can students show a genetic factor without studying genes?
Compare organisms with different parents in the same surroundings. Two breeds of cattle on one pasture, or two seed varieties in one field with the same care, show an inherited difference in growth. The how of inheritance is left for later standards.
What should students measure to show growth?
Height is easy, but mass (how much matter the organism has) and leaf count often tell more. A plant in dim light can grow tall and thin while adding little mass. For animals, mass or length at a given age works well. Always measure every group the same way and on the same day.
Why do fish grow larger in large ponds?
In a large pond each fish usually has more food and more space, so it grows faster. When the same number of fish live in a small pond, they share less food. It is an environmental effect, which is why the fish in the comparison should be one species from one source.
Can a factor have different effects in different conditions?
Yes. One crop variety may grow best with plenty of water while another grows better in drought. The Clarification Statement mentions "different varieties of plant seeds growing at different rates in different conditions", and farmers use this when they choose seeds for their region.
How does MS-LS1-5 connect to other standards?
It builds on grade 3 ideas that traits are inherited (3-LS3-1) and that the environment can change them (3-LS3-2). In middle school it links to resource limits in ecosystems (MS-LS2-1) and to how people breed organisms for desired traits (MS-LS4-5). In high school, HS-LS3-3 uses statistics to describe how traits vary.
07
Related Standards
6 standards
These standards connect to MS-LS1-5: prerequisites to review first, parallel standards at the same level, and next steps that build on it.
Before this lesson
3-LS3-2Prerequisite
Use evidence to explain that traits can be influenced by the environment
Lesson coming soon
3-LS3-1Prerequisite
Use data to show that traits are inherited from parents and vary in a group
Lesson coming soon
Alongside
MS-LS2-1Parallel
Use data to show how resource availability affects organisms and populations
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