May/June 2017 – Vol. 29 No. 7

Check an Apple for Pollination

Posted: Wednesday, February 1st, 2012

by Camilla Barry

Major Science Concept: Successful pollination results in seed production.

Subject: Botany

Review pollination with the students. Pollination is the process whereby pollen fertilizes the female part of a flower. Seeds are the result of successful pollination.

If you cut a melon, you will see many seeds (fig 1). Likewise, a sunflower may have several thousand seeds. Does that mean every seed will grow? No. Many melon and sunflower seeds are not complete. There is an outer  seed coat, but no embryo inside.

Figure 1

Definition:

Embryo: an organism that is in its earliest stages of development.

Fruits having no seeds or incomplete seeds are proof that pollination wasn’t successful. Fruit can form even if there was no pollination, but the fruit is often smaller and inferior. Apples are an easy fruit to examine for pollination because:

a)    They are readily available

b)    They are inexpensive

c)     The seeds are easy to find

d)    Apples do not contain many seeds, so they are easier to count.

1) Slice an apple crosswise (fig 2). Notice the star-shaped pattern inside. These are the seed “pockets”. How many seed pockets are there? (Five)

Figure 2

Apples have the capacity to hold 2 seeds in each seed pocket. If an apple blossom is completely pollinated, there will be 10 seeds (2 seeds in each of 5 pockets).

2)    Use your fingers or a pencil to gently pry seeds from the pockets and count them (fig 3). Are the seeds complete or just a shell? You may have to guess by looking to see how round they are, if you cannot open the seeds. If a seed was sliced in half when the apple was cut, count it as a single seed.

Figure 3

3)   More advanced students can calculate the ratio of actual seeds produced to the total seed capacity:

Seeds in my apple/10 = ?

Compare apples from more than one source:

This lesson is much more interesting if apples are purchased from different vendors, or if apples are brought from home gardens. If you purchase the apples, try to discover where they were grown. Then the number of seeds from one type of apple may be compared to the seeds of another type of apple.

Many farmers believe there is a direct relationship between the number of seeds in an apple and the quality of the apple. The apple may be bigger, rounder, or juicier if there are more seeds. Others say they have not noticed such a relationship. Ask your students what they think, after observing their apples and counting the seeds.

Why do some apples have more seeds?

a)    Apple trees are pollinated by bees.  If there are no bees near the orchard, there will be no pollination, and no seeds.

b)    Apple trees must be pollinated with the pollen from another apple tree.  Bees must bring the pollen from one tree to another for seeds to form. The trees must be close enough that bees will visit both trees. However, bees can visit trees as far as 1.5 kilometers apart, so the trees do not have to be in the same garden.

Notice 5-part symmetry in apples:

Remember the 5-pointed star shape in the middle of the apple. Can you find another instance of 5-parts on the apple fruit? (the bottom of the apple has a 5-part scar). Look at the picture of the apple blossom (fig 4).  What do you notice? (there are 5 petals).

Figure 4

Questions:

  1. 1. Can a fruit develop without seeds? (yes)
  2. 2. Are all the seeds in a fruit capable of growing? (not necessarily) Why not? (the flower corresponding to that seed may not have been pollinated)

3. Serena sees many bees on the flowers of the single apple tree in her front yard. She is thinks she will be able to gather many seeds from her apples. Is she right? (maybe) What else does she need to be certain of many seeds? (another apple tree nearby).

4. Mohammed Gul is an apple farmer. He has a large orchard of apple trees. He wants to make sure no bugs bother his plants. He sprays pesticide everywhere. The pesticide will kill all bugs. Will he have apples? (Yes. Pesticide does not keep fruit from forming).

5. Will Mohammed Gul’s apples be large and tasty? Why or why not? (They will not have many, or possibly no, seeds because there will be no bees to pollinate the flowers. Some farmers believe there is a correlation between pollination and high-quality fruit.

Alignment to Standards:

Kindergarten Life Sciences: Students know how to identify major structures of common plants and animals (e.g., stems, leaves, roots, arms, wings, legs).

First Grade Life Sciences: Students know different plants and animals inhabit different kinds of environments and have external features that help them thrive in different kinds of places.

Second Grade Life Sciences: Students know flowers and fruits are associated with reproduction in plants.

Third Grade Life Sciences: Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.

Fourth Grade Life Sciences: Students know many plants depend on animals for pollination and seed dispersal, and animals depend on plants for food and shelter.

Camilla Barry teaches K-5 science at Park School in the Mill Valley School District and is founder of Classrooms Across Cultures.

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Leave a Reply

LATEST POST

Participate in Chemistry Education Research Study, Earn $500-800 Dollars!

Posted: Tuesday, May 9th, 2017

WestEd, a non-profit educational research agency, has been funded by the US Department of Education to test a new molecular modeling kit, Happy Atoms. Happy Atoms is an interactive chemistry learning experience that consists of a set of physical atoms that connect magnetically to form molecules, and an app that uses image recognition to identify the molecules that you create with the set. WestEd is conducting a study around the effectiveness of using Happy Atoms in the classroom, and we are looking for high school chemistry teachers in California to participate.

As part of the study, teachers will be randomly assigned to either the treatment group (who uses Happy Atoms) or the control group (who uses Happy Atoms at a later date). Teachers in the treatment group will be asked to use the Happy Atoms set in their classrooms for 5 lessons over the course of the fall 2017 semester. Students will complete pre- and post-assessments and surveys around their chemistry content knowledge and beliefs about learning chemistry. WestEd will provide access to all teacher materials, teacher training, and student materials needed to participate.

Participating teachers will receive a stipend of $500-800. You can read more information about the study here: https://www.surveymonkey.com/r/HappyAtoms

Please contact Rosanne Luu at rluu@wested.org or 650.381.6432 if you are interested in participating in this opportunity, or if you have any questions!

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

2018 Science Instructional Materials Adoption Reviewer Application

Posted: Monday, May 8th, 2017

The California Department of Education and State Board of Education are now accepting applications for reviewers for the 2018 Science Instructional Materials Adoption. The application deadline is 3:00 pm, July 21, 2017. The application is comprehensive, so don’t wait until the last minute to apply.

On Tuesday, May 9, 2017, State Superintendent Tom Torlakson forwarded this recruitment letter to county and district superintendents and charter school administrators.

Review panel members will evaluate instructional materials for use in kindergarten through grade eight, inclusive, that are aligned with the California Next Generation Science Content Standards for California Public Schools (CA NGSS). Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Lessons Learned from the NGSS Early Implementer Districts

Posted: Monday, May 8th, 2017

On March 31, 2017, Achieve released two documents examining some lessons learned from the California K-8 Early Implementation Initiative. The initiative began in August 2014 and was developed by the K-12 Alliance at WestEd, with close collaborative input on its design and objectives from the State Board of Education, the California Department of Education, and Achieve.

Eight (8) traditional school districts and two (2) charter management organizations were selected to participate in the initiative, becoming the first districts in California to implement the Next Generation Science Standards (NGSS). Those districts included Galt Joint Union Elementary, Kings Canyon Joint Unified, Lakeside Union, Oakland Unified, Palm Springs Unified, San Diego Unified, Tracy Joint Unified, Vista Unified, Aspire, and High Tech High.

To more closely examine some of the early successes and challenges experienced by the Early Implementer LEAs, Achieve interviewed nine of the ten participating districts and compiled that information into two resources, focusing primarily on professional learning and instructional materials. Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Using Online Simulations to Support the NGSS in Middle School Classrooms

Posted: Monday, May 8th, 2017

by Lesley Gates, Loren Nikkel, and Kambria Eastham

Middle school teachers in Kings Canyon Unified School District (KCUSD), a CA NGSS K-8 Early Implementation Initiative district, have been diligently working on transitioning to the Next Generation Science Standards (NGSS) integrated model for middle school. This year, the teachers focused on building their own knowledge of the Science and Engineering Practices (SEPs). They have been gathering and sharing ideas at monthly collaborative meetings as to how to make sure their students are not just learning about science but that they are actually doing science in their classrooms. Students should be planning and carrying out investigations to gather data for analysis in order to construct explanations. This is best done through hands-on lab experiments. Experimental work is such an important part of the learning of science and education research shows that students learn better and retain more when they are active through inquiry, investigation, and application. A Framework for K-12 Science Education (2011) notes, “…learning about science and engineering involves integration of the knowledge of scientific explanations (i.e., content knowledge) and the practices needed to engage in scientific inquiry and engineering design. Thus the framework seeks to illustrate how knowledge and practice must be intertwined in designing learning experiences in K-12 Science Education” (pg. 11).

Many middle school teachers in KCUSD are facing challenges as they begin implementing these student-driven, inquiry-based NGSS science experiences in their classrooms. First, many of the middle school classrooms at our K-8 school sites are not designed as science labs. Learn More…

Powered By DT Author Box

Written by NGSS Early Implementer

NGSS Early Implementer

In 2015 CSTA began to publish a series of articles written by teachers participating in the NGSS Early Implementation Initiative. This article was written by an educator(s) participating in the initiative. CSTA thanks them for their contributions and for sharing their experience with the science teaching community.

Celestial Highlights: May – July 2017

Posted: Monday, May 8th, 2017

May Through July 2017 with Web Resources for the Solar Eclipse of August 21, 2017

by Robert C. Victor. Twilight sky maps by Robert D. Miller. Graphs of planet rising and setting times by Jeffrey L. Hunt.

In spring and summer 2017, Jupiter is the most prominent “star” in the evening sky, and Venus, even brighter, rules the morning. By mid-June, Saturn rises at a convenient evening hour, allowing both giant planets to be viewed well in early evening until Jupiter sinks low in late September. The Moon is always a crescent in its monthly encounters with Venus, but is full whenever it appears near Jupiter or Saturn in the eastern evening sky opposite the Sun. (In 2017, Full Moon is near Jupiter in April, Saturn in June.) At intervals of 27-28 days thereafter, the Moon appears at a progressively earlier phase at each pairing with the outer planet until its final conjunction, with Moon a thin crescent, low in the west at dusk. You’ll see many beautiful events by just following the Moon’s wanderings at dusk and dawn in the three months leading up to the solar eclipse. Learn More…

Powered By DT Author Box

Written by Robert Victor

Robert Victor

Robert C. Victor was Staff Astronomer at Abrams Planetarium, Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs, CA. Robert is a member of CSTA.