Life Cycling
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Pre-site Activities/Teacher
Led
Grade Level: 2
Content
Area: Science
Time to Complete: 45 minutes
Title of
Lesson: Measuring Temperature and
Measuring Frog Length
South Carolina State Standards
Addressed:
|
2-1.1
|
Carry out simple
scientific
investigations to answer
questions about familiar
objects and events. |
|
2-1.2 |
Use tools (including
thermometers, rain
gauges, balances, and
measuring cups) safely,
accurately, and
appropriately when
gathering specific data
in US customary
(English) and metric
units of measurement. |
|
2-1.3 |
Represent and
communicate simple data
and explanations through
drawings, tables, and
metric units of
measurement. |
|
2-1.4 |
Infer explanations
regarding scientific
observations and
experiences. |
|
2-1.5 |
Use appropriate safety
procedures when
conduction
investigations. |
Lesson Description:
Students will learn how to use a thermometer, and take the
temperature of the air, as well the temperature of a beaker of water (these
activities will be done in the field when they get to Paris Mountain State
Park).
Students will also practice measuring length, using a 6”
ruler, and models of tadpoles/frogs in 5 stages of a frog’s life cycle.
Students will also put these models in order from youngest to oldest (at the
park, they will measure some animals they find, and compare younger to older
ones).
Focus Questions for Students:
| 1. |
What is temperature? |
| 2. |
What kind of instrument is usually
used to measure temperature? |
| 3. |
How does water temperature affect
life cycle growth in animals? |
| 4. |
What kind of instrument is usually
used to measure length? |
| 5. |
What can the length of an animal
tell us about its growth? |
Culminating Assessment:
|
1. |
Students will be able to say that temperature is defined as
how hot or cold something is, and that a thermometer is usually used to
measure temperature. |
|
2. |
Students will be able to say that animals have a range of
temperatures when they do most of their growing. If it is too hot or too
cold for that animal, it won’t grow much, if at all. |
|
3. |
Students will be able to say that a ruler can be used to
measure length. |
|
4. |
Students will be able to say that if you have a few of the
same type of animal, found in the same place, you can compare their length
to make a guess about which one is youngest, and which one is oldest.
|
Materials/Equipment:
Teacher Preparation:
| 1. |
Read background information. |
| 2. |
Be
prepared to introduce temperature and length to students, in
relation to life cycles. |
Background Information:
Temperature is a measure of how hot or how cold something
is.
Scientists often record temperature in Celsius instead of
Fahrenheit. A reading of 20 degrees Celsius is about the same as 70 degrees
Fahrenheit. Zero degrees Celsius is the same as 32 degrees Fahrenheit.
When studying life cycles of cold-blooded animals, like insects, amphibians,
fish, and reptiles, temperature plays a major role in their growth and
development. Each species of animal in a particular habitat (for example,
the Eastern pond hawk dragonfly at Paris Mountain State Park), has an
optimum temperature in which its larva stage, which lives underwater in Lake
Placid, will grow quickly. Beyond a certain temperature, development
stops. Due to a shorter ‘growing season,’ dragonflies in colder climates up
north may take up to 5 years to get big enough to emerge from the larval
stage, into an adult. Bullfrog tadpoles up north may take 2 years to
develop into adult frogs. Here in South Carolina, the time is closer to one
year, due to warmer temperatures for more of the year
The
adult dragonfly or butterfly must wait till the air warms to a certain
temperature before it can fly each day.
Temperature also can determine whether a water turtle hatches as a male or a
female turtle. In painted turtles, for example, when the temperature in the
nest is between 24- 26 degrees Celsius, only males are produced. At an
incubation temperature of 30 degrees Celsius, 96 percent of hatchlings are
female.
The
parents of many animals, such as birds and some mammals, must keep their
babies warm. If the eggs of birds are not kept warm enough, the eggs will
not hatch.
Length
is often measured with a ruler, in inches. When you have a sample of
animals that are the same kind, and living in the same habitat, you can
compare their sizes to guess which is youngest and which is oldest. Often,
the point at which an animal, such as a dragonfly nymph, metamorphoses into
an adult, is determined by how large it grows.
In the creeks and lakes at Paris Mountain State Park, we
often find dragonfly nymphs that look alike except for their size. We know
that dragonflies go through 3 life cycle stages: egg, nymph, adult. While
in the nymph stage, they molt at least 11 times, each time getting bigger,
and with more complex eyes (an adult dragonfly has marvelous compound
eyes). For the final molt, the dragonfly crawls out of the water, onto a
plant stem, where it sheds its exoskeleton one last time, revealing
beautiful wings. After drying out, it flies away.
Tadpoles slowly develop into adult frogs. After hatching
from a cluster of thousands of jelly-like eggs, the tadpole swims in the
water with a long tail, breathing with gills and eating algae plants. Over
time, the tail goes into the body, legs appear and lungs develop. The
tadpole becomes a frog, designed to breathe air and to use its tongue to
catch small animals. How fast it grows (based on temperature and food
supply), determines how soon it becomes an adult.
The
correct and safe way to use a thermometer.
|
1. |
Hold the end of the thermometer with the hole in the blue
case. |
|
2. |
Looking at the thermometer, notice marked numbers going up
in specific increments, marked with a bold line. |
|
3. |
The distance between each number is consistently marked with
the same number of small lines. Each line represents a
specific degree. |
|
4. |
An indicator line (usually red) will indicate the
temperature. |
|
5. |
Always put thermometer bulb end down into the substance being
tested. |
|
6. |
Note: Alcohol-filled thermometers are safer than
mercury-filled thermometers, and do not need to be shaken to the lowest
temperature before use. |
| |
Note: These thermometers should be left inside their blue
plastic case. |
Procedures:
A. Temperature Activity Note: If you like, make copies of the
worksheet for each group or each student.
Or just use for class discussion.
| 1. |
Discuss temperature as a measurement of how hot or how cold
something is. |
|
2. |
Discuss the importance of temperature in terms of an animal’s
life cycle. |
|
3. |
Discuss
questions that could be answered through investigations with
thermometers. For example: Which will be cooler: the temperature of
the air or of the water? |
|
4. |
Demonstrate the
correct and safe use of a thermometer. |
|
5. |
Divide students into groups of 4 or 5. There are enough
thermometers for six groups with each group using one thermometer,
one timer, and one 250 ml beaker.
Timer note: To
start timer, just press ‘on,’ then ‘start.’ Press ‘stop’ and record
data when it gets to the time you want. Timer will turn off after a
few minutes without use. |
|
6. |
One student
holds the thermometer in the air (holding the end opposite the
bulb), while another student (or the teacher) starts the timer, and
sets it for two minutes. |
|
7. |
At the end of
two minutes, record the temperature on the worksheet. |
|
8. |
Using the 250 ml
beakers, each group collects one 100 ml sample of water from the
coldwater tap. |
|
9. |
Holding the end
of the thermometer (opposite the bulb), place the thermometer in the
first sample for two minutes Let the bulb rest on the bottom.
|
|
10. |
At the end of two minutes, record the water temperature on
the worksheet. |
B. Measuring Frog Length
|
1. |
Discuss length
as a measurement of how long something is, and the ruler as an
instrument for measuring length. |
|
2. |
Discuss how
measuring length of animals that are the same kind, found in the
same habitat, can help determine which is youngest and which is
oldest. |
|
3. |
Discuss the life
cycle of a frog. |
|
4. |
With the
students divided into 6 groups of 5 or less, hand out a set of 5
rulers, and 1 bag of plastic tadpole/frog models to each group.
|
|
5. |
Discuss
questions that could be answered by measuring with a ruler. For
example, will the tadpole be smaller than the adult frog? |
|
6. |
Each group
places the plastic models in order from youngest to oldest. Discuss
visible changes that occur as the tadpole develops. |
|
7. |
Each student
measures the body of each tadpole/frog with their ruler (they don’t
measure the tail). |
|
8. |
On the
worksheet, each group or student marks where the youngest and the
oldest model measured to on the ruler. Discuss results.
|
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