BOT 111.1 Lab exercise 9 PDF

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EXERCISE 9The FruitName: Gwyneth N. Maratas Date performed: February 21, 2019 Section: BOT 111 BC Date submitted: February 28, 2019I. IntroductionFruits develop from flowers. After pollination and fertilization, hormones trigger the various parts of the flower to enlarge and change, eventually devel...

Description

EXERCISE 9 The Fruit Name: 2019 Section:

I.

Gwyneth N. Maratas BOT 111.1 BC

Date performed: February 21, Date submitted: February 28, 2019

Introduction

Fruits develop from flowers. After pollination and fertilization, hormones trigger the various parts of the flower to enlarge and change, eventually developing into a structure that houses, protects, and sometimes nourishes and aids in dispersing the plant’s seeds. Depending on the type of plant, the mature ovary may form a juicy fleshy fruit or it may develop into a dry fruit. Certain foods commonly termed vegetables, including tomatoes, squash, peppers, and eggplant, technically are fruits because they develop from the ovary of a flower.

Figure 1. Fruit structure Fruits vary widely in physical appearance, but their basic structure is the same. The outermost layer is called the exocarp; the middle layer is the mesocarp; and the inner layer, the endocarp. These three regions together are called the pericarp. The vast variety of colorful and interesting fruits on earth poses a challenge for scientists who seek to classify them. One widely used classification system divides fruits into fleshy and dry types. II.

Objectives

The main purpose of the exercise is to be able to characterize the different types of fruits, identify the parts of a fruit and determine the floral origin of the various structures of a fruit, and describe the purpose of a fruit and its importance in seed dispersal.

III.

Materials and Methods The materials and equipment utilized in the exercise are the following:

Table 1. List of specimens used in conducting the exercise Part A Vigna sesquipedalis (Yard long bean) Lablab purpurea (Bataw) Psidium guajava (Guava) Anona squamosa (Atis) Fragaria × ananassa (Strawberry) Ananas comosus (Pinya) Cucumis sativus (Cucumber) Cucurbita moschata (Kalabasa) Citrus microcarpa (Kalamansi) Citrus grandis (Pomelo) Mangifera indica (Mango) Spondias purpurea (Sinigwelas) Malus pumila (Apple) Abelmoschus esculentus (Okra) Ricinus communis (Castor bean) Bixa orellana (Atsuwete) Helianthus annuus (Sunflower) Cosmos sp. Oryza sativa (Rice) Zea mays (Corn) Cocos nucifera (Coconut) Solanum lycopersicum (Tomato) Part B Pisum sativum (Pea) Lablab purpurea (Bataw) Phaseolus lunatus (Patani) Table 2. List of materials and equipment used in conducting the exercise Materials and Equipment Function Used to cut and dissect the specimen to be Scalpel examined Used to observe the specimen in microscopic Light compound microscope level Used to mount the specimen under the Glass slides and coverslips microscope Beaker Used to soak peas for 24 hours Pen and paper Used to record observations PART A. Fruit Morphology The type of fruit according to composition and origin, and according to texture and dehiscence were examined in each specimen. The fruit variation of specimens was identified and listed in Table 2. Each of the fruits were cut crosswise and lengthwise to identify parts, and determine the type of placentation. An illustration of sliced specimen was made with labelled parts.

PART B. Parts of a fruit

The external appearance of the pod was examined. The number of remaining sepals were recorded. The pod was carefully opened along the curved edge using the scalpel. The number of peas in the pod were counted. The number of fibers seen attached by a short stalk were recorded. A beaker was filled with room temperature water and soaked a fresh pea for a day. The seed coat from the pea was carefully removed using a dissecting needle. The cotyledons were separated to observe the embryo plant. A scalpel was used to cut a thin slice through a cotyledon and placed it on a microscope slide. The parts of the embryo plant were observed in microscopic level. An illustration of observation was made. IV.

Results and Discussions

PART A. Fruit Morphology Types of Fruits 1. According to composition and origin a. Simple fruit – a fruit that results from the ripening of a single ovary. b. Compound fruit – when the fruit develops from several ovaries. Types of compound fruits Aggregate fruit – a fruit that develops from several ovaries that belong to a single flower and becomes crowded into a mass. These are joined together by a common receptacle. Multiple or collected fruit – a fruit that is derived from the ovaries of several flowers that unite into a mass. Example: cone – a multiple fruit consisting of overlapping appressed scales, each scale bearing one or two seeds on its surface. c. Accessory fruit – fruit that develops from other parts of the flower other than the ovary. Example: pome – a fruit in which most part develops from the receptacle. 2. According to texture and dehiscence a. Fleshy fruits – a general term to refer to fruits where all or most of the pericarp is soft and fleshy at maturity. Berry – a fruit where the entire pericarp become fleshy. Hesperidium – a berry with a leathery rind. Pepo – a unilocular berry with a hard rind that develops from an inferior ovary Drupe or stone fruit – a type of fruit where the exocarp is thin, the mesocarp is thick and fleshy, and the endocarp is hard and stony.

b. Dry fruits – fruits in which the entire pericarp becomes dry often brittle or hard at maturity. Dehiscent dry fruits – fruits that split open along definite points at maturity thus releasing the seeds. Capsule – a fruit that is derived from two or more united carpels and splitting in various ways. Legume or pod – a dehiscent fruit derived from two or more united carpel and splits open along 2 seams or sutures. Silique – an elongated, two-locular fruit with two parietal placentae, and usually with two valves separating from the persistent placentae and septum as in Brassicaceae. Indehiscent dry fruits – dry fruits that do not split open along definite sutures at maturity. These fruits usually contain one or two seeds. Achene – a small, unilocular, one-seeded fruit, the seed is attached to the ovary wall at a single point. Acorn – the hard, dry indehiscent fruit of oaks having a single, large seed and a cup-like base. Bur – a fruit with often hooked or barbed spines or appendages. Caryopsis or grain – a seed-like fruit resembling an achene but having the seed coat firmly united with ovary wall. Nut – a one-seeded fruit that resembles and achene, but larger. It has long shell, with much-thickened, hard pericarp. Samara – a winged achene. Schizocarp – a dry fruit that splits along one-seeded carpels or parts. Utricle – a one-seeded fruit with a thin, bladdery and inflated wall. This type of fruit is characteristic of Amaranthaceae.

Table 3. Fruit variation of specimens Dehiscent/ Indehiscent

Dry/Fleshy

Type of Fruit

Type of Placentation

Edible Part

Dehiscent

Dry

Legume/Pod

Marginal

Fruit

–

Fleshy

Berry

Axile

Fruit

–

Fleshy

Aggregate Achene

Basal

Fruit

–

Fleshy

Pepo

Pariental

Fruit

–

Fleshy

Hesperidium

Axile

Fruit

–

Fleshy

Drupe

Basal

Fruit

–

Fleshy

Pome

Basal Axile

Fruit

–

Fleshy

Berry

Basal

Fruit

Indehiscent

Dry

Achene

Basal

Seed

Indehiscent

Dry

Caryopsis/Grai n

Basal

Seed

–

Fleshy

Drupe

Basal

Fruit

Dehiscent

Dry

Legume/Pod

Marginal

Seed

–

Fleshy

Aggregate

Basal

Fruit

–

Fleshy

Multiple

Basal

Fruit

–

Fleshy

Pepo

Pariental

Fruit, Leaf, Flower, Stem, Seed

–

Fleshy

Hesperidium

Axile

Fruit

–

Fleshy

Drupe

Axile

Fruit

Abelmoschus esculentus

Dehiscent

Dry

Capsule

Axile

Fruit, Leaf, Flower, Seed

Bixa orellana Cosmos sp.

Dehiscent Indehiscent

Dry Dry

Pariental Basal

Seed

Zea mays

Indehiscent

Dry

Capsule Achene Caryposis/Grai n

Basal

Seed

Solanum lycopersicum

–

Fleshy

Berry

Axile

Fruit

Specimen Vigna sesquipedalis Psidium guajava Fragaria × ananassa Cucumis sativus Citrus microcarpa Mangifera indica Malus pumila Ricinus communis Helianthus annuus Oryza sativa Cocos nucifera Lablab purpurea Anona squamosa Ananas comosus Cucurbita moschata Citrus grandis Spondias purpurea

The table above shows the variation of fruit specimen. These were classified according to composition and origin and according to texture and dehiscence. The type of placentation for each specimen was also identified as well as their edible parts.

Figure 1. Vigna sesquipedalis cut in half

Figure 2. Mangifera indica cut in half Figure 3. Psidium guajava cut in half

Figure 4. Malus pumila cut in half Figure 5. Cucumis sativus cut in half

Figure 6. Helianthus annuus cut in half Figure 7. Citrus microcarpa cut in half

Figure 8. Oryza sativa cut in half

Figure 15. Citrus grandis cut in half

Figure 9. Cocos nucifera cut in half

Figure 10. Abelmoschus esculentus cut in half

Figure 11. Ananas comosus cut in half

Figure 12. Bixa orellana cut in half

Figure 13. Cucurbita moschata cut in half

Figure 14. Cosmos sp. cut in half

Figure 16. Zea mays cut in half

Figure 17. Solanum lycopersicum cut in half

Figure 18. Ricinus communis cut in half

Figure 19. Fragaria × ananassa cut in half

Figure 20. Lablab purpurea cut in half

Figure 21. Anona squamosa cut in half

PART B. Parts of a fruit After pollination or fertilization occurs, the ovules in the ovary of a flower mature into a fruit containing seeds. Most of the flower parts die and the seeds begin to develop. The wall of the ovule becomes the hard seed coat, which may aid in dispersal and helps to protect the embryo plant until it begins to grow.

As the seeds develop, the surrounding ovary enlarges and becomes the fruit. A fruit is the structure that contains the seeds of an anthophyte. A fruit is as unique to a plant as is its flower; most plants can be identified by examining their fruits. We are most familiar with fleshy, often sweet fruit, such as apples and grapes. But other plants develop dry fruits, such as peanuts and sunflower “seeds.” In dry fruits the ovary surrounding the seeds hardens as the fruit matures. Many foods that we call grains or vegetables are actually fruits. A pea pod is actually a fruit, although it is commonly called a vegetable. Peas and their pods are usually consumed before they mature and dry, so people rarely see their natural development. Like all fruits, the pea pod develops from a flower, and parts of the flower can still be identified after pollination and maturation. In this investigation, the features of a pea pod flower remnants were observed and studied how seeds form and the parts of a fruit that are important to its reproduction. Figure 22. Pisum sativum pod

Figure 23. External appearance of Pisum sativum pod

Figure 24. Remaining sepals of Pisum sativum

Figure 25. Remaining style of Pisum sativum

Figure 27. Sliced Pisum sativum seeds Figure 26. Pisum sativum pod and seeds Table. 4. Observations in external appearance of Pisum sativum pod No. of sepals Length of the pod No. of seeds No. of fibers Replica 1 4 2.5 in. 8 8

Color and shape of seed Lightgreen, ovoid

Replica 2

9

3 in.

9

9

Lightgreen, ovoid

Two Pisum sativum pod were observed. The number of sepals, seeds, and fibers were recorded. As well as the length of the pod, and the color and shape of seeds were recorded.

Endosperm Embryo

Figure 28. Pisum sativum seed under 40x magnification The figure above shows a Pisum sativum seed under 40x magnification. The seed coat of the specimen was removed, but we can clearly see the endosperm as well as the embryo of the seed. V.

Study Questions 1. In some of the fruits, the floral parts are persistent even up to maturity. Identify these parts. Consider Psidium guajava and Oryza sativa. What are the structures attached at the upper part of the two fruits? The calyx and sometimes corolla. 2. Is there an advantage of dry fruits over fleshy fruits? Give reasons. The fleshy fruits are adapted to animal dispersal whereas the dry fruits are adapted for dispersal by the expulsion, wind and some get attached to fur or feathers of animals. 3. Are there differences in morphology between monocot and dicot fruits? Tabulate these differences (if any). The fruits of monocots usually have three parts. The seeds are often large and fleshy. The fruits and the seeds of dicots are very variable in shape, size and texture. It can have any number of chambers, from none to many. There are often more seeds in a dicot fruit than in a monocot fruit.

VI.

References  Balngcod T.D. and Buot I.E. Jr. (2011). Plant Taxonomy: A Laboratory Manual (A Revised Edition). Philippine Society for the Study of Nature. 109 pp.  Chapter 14: Seed and Fruits. Retrieved from http://wwwplb.ucdavis.edu/courses/bis/1c/text/Chapter14nf.pdf  Mill P. (2019). Malus pumila. Go Botany. Retrived from

https://gobotany.newenglandwild.org/species/malus/pumila/  National Park Board, Singapore (2013). Retrieved from https://florafaunaweb.nparks.gov.sg/Special-Pages/plant-detail.aspx?  Plant Reproduction. (n.d.). Retrieved from: http://www.lessonsite.com/archivepages/biology/bio logylabs1.1_secondsemester.pdf  Stern, Kingsley R. "Fruit." Microsoft® Student 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.  Lifeeasy Authors (n.d.). How does a fleshy fruit differ from a dry fruit? Lifeeasy Biology. Retrieved from http://www.biology.lifeeasy.org/1001/how-does-a-fleshy-fruit-differfrom-a-dry-fruit  Fruits (Types and Placentations). Quizlet. Retrieved from https://quizlet.com/162915309/fruits-types-and-placentations-flash-cards/  Monocots and Dicots (Chart Showing Differences). The Seed Site. Retrieved from http://theseedsite.co.uk/monocots2.html  The Editors of Encyclopaedia Britannica (2018). Fruit. Encyclopædia Britannica. Encyclopædia Britannica, inc. Retrieved from https://www.britannica.com/science/fruitplant-reproductive-body  Wikipedia contributors (2019). Fruit. In Wikipedia, The Free Encyclopedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Fruit&oldid=884382761 

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