BIOLOGY PRACTICAL ON OIL PALM FRUIT AND MANGO FRUIT AS SPECIMENS.

Classify the specimen (oil palm fruit)

A drupe because it has a stony endocarp and a fleshy mesocarp.

Oil palm is a fleshy fruit because the mesocarp is fleshy at maturity

True fruit because it develops from the ovary only

Bracteolate fruit and simple fruit because they develop from one carpel

Based on this, the flower from which the fruit develops is syncarpous

A Drupe;

Has a thin outer epicarp
Middle fleshy mesocarp
Inner hard and woody endocarp protects the seed

Type of seed

Monocotyledonous seed
Or Endospermous seed

DRAWING OF THE EXTERNAL STRUCTURE OF OIL PALM FRUIT.

Observable Features or Characteristics

Style
Stigma lobes (3 in number) offer protection
Point of attachment to the plant
Perianth lobes (6 in number) provide protection
Bracteoles (3 in number) for protection
Reddish epicarp to attract animals for dispersal

Agricultural Classification of Oil Palm

Cash crop

Ecological importance of the specimen (oil palm fruit)

Reproduction
Food store/ source of food
Dispersal
Survival of adverse conditions

Economic importance specimen (oil palm fruit)

Source of food/oil
Income
Employment
Raw materials for industries
Medicinal
Fibre and kernel shells are used as biofuel

Nutrients in oil palm

Vitamin A in fibrous mesocarp
Fats and oils in the mesocarp of the fruit wall and the endosperm of the seed

Two nutritive tissues in the oil palm fruit

Mesocarp produces red palm oil, which contains fats and oils, and carotene is used to synthesise vitamin A
Endosperm (kernel) produces palm kernel oil containing fats and oils.

Importance of food nutrients in oil palm fruit

Functions of vitamin A

Night vision (Synthesis of rhodopsin)
Healthy throat
Healthy eyes
Healthy skin
Normal growth
It controls normal epithelial structure and growth

Deficiency of vitamin A

Night blindness
Colds and infections of the throat
Sore eyes
Unhealthy skin (dry & scaly)
Xerophthalmia (permanent blindness)
Stunted growth

Functions of fats

Hold and protect vital organs in animals
Insulation of the body
Sources of fat-soluble vitamins (A, D, E and K)
Formation of cell membranes
Provide energy
Used for long-term energy storage

Agent of dispersal of oil palm fruit:

Animals

Examples;

Human,
monkey,
squirrel,
bats,
rats,
vulture

Reasons:

Coloured epicarp
Sweet-scented and fleshy mesocarp

Explain briefly how oil palm fruit is dispersal by animals:

Bright colour of epicarp and succulent inner part(s)
Attract animals
Which uses it as food
Animals may carry the fruit away
Larger seeds with hard endocarp may be thrown away to germinate elsewhere
Thereby bringing about dispersal.

Testing for food nutrients in oil palm fruit

Obtain a white paper
Scrub away some mesocarp
Rub the scrubbed portion on the paper
Allow to dry
Observe in light
Translucent mark forms
Fats and oils present

Iodine test on oil palm

Scrub away some mesocarp
Drop iodine solution on a scrubbed portion of
the oil palm fruit
No blue-black colour forms
Starch is absent in the fruit

Similarities between the oil palm fruit and the mango fruit.

Hard endocarp
Fibrous mesocarp
Single large seed
Brightly coloured epicarp.

Differences between oil palm and mango fruit.

OIL PALM FRUIT	MANGO FRUIT
Mesocarp not juicy	Fleshy or juicy mesocarp
The seed is pear-shaped	The seed is kidney-shaped
Persistent style	No persistent style

Differences between oil palm fruit and orange fruit

OIL PALM FRUIT	ORANGE FRUIT
Hard endocarp	Soft endocarp
Fibrous mesocarp	Fleshy mesocarp
One seed	Many seeds
Smooth epicarp	Rough epicarp
Persistent style	No persistent style

DRAWING OF THE LONGITUDINAL SECTION OF COCONUT FRUIT.

Similarities between coconut and oil palm fruits

Smooth epicarp
Fibrous mesocarp (note: fibrous and spongy in coconut only)
Hard endocarp
Large seed
One seed

Adaptations of the coconut for water dispersal

Waterproof epicarp (waxy epicarp) repels water
Spongy mesocarp to provide buoyancy
Stony endocarp to protect the embryo. e.g. coconut fruit, water lily (Nymphaea) seed

Explain briefly how Coconut is dispersed

Dispersed by water
The coconut is a fibrous drupe.
It is light because of the spongy mesocarp
The epicarp is waterproof and repels water.
The hard endocarp protects the embryo
The fruit is carried by moving water from the area of the parent over a long distance,
Where it is deposited by water, thereby bringing about dispersal

SPECIMEN: MANGO FRUIT

Mango fruit is a true and simple fruit. It is also a fleshy fruit, but a drupe with only a seed of basal placentation.

Observable internal features

Thin, brightly coloured epicarp
Large, Fibrous, yellowish, and juicy mesocarp
Hard endocarp
Cotyledon of a seed
Remains of style (external)
Point of attachment to plant (external)

DRAWING OF THE LONGITUDINAL SECTION OF MANGO FRUIT.

Agents of dispersal

Animal (Human and Monkey)

Reasons

Juicy fibrous mesocarp serves as food
Brightly coloured epicarp attracts animals
Sweet-scented mesocarp attracts animals

Dispersal of mango fruit

The epicarp of the mango attracts animals
Which feed on the juicy fleshy mesocarp
Throw the seed away
The seed is still protected by the hard endocarp
The seed germinates under favourable conditions

Differences between a ripe mango and an unripe mango

UNRIPE MANGO	RIPE MANGO
Green epicarp	Brightly or yellowish coloured epicarp
Creamy mesocarp	Yellowish mesocarp
Harder mesocarp	Softer mesocarp
Not sweet-scented	Sweet scented

Economic importance of the mango fruit.

Foreign exchange/income
Source of food
Raw material for industries
Employment

Classes of food in mango

Vitamins
Carbohydrates
Dietary fibre
Water

Adaptation of the mango fruit to it habitat

The coloured epicarp attracts animals for dispersal and also protects the fruit
Juicy/succulent mesocarp is a source of food for animals and thus attracts them to disperse it
The hard endocarp protects the seed
A large cotyledon (since one is seen in LS) is a source of food for the embryo during germination.
Embryo develops into a seedling.

lodine test on mango fruit

Mango does not contain starch, even though it contains sugars
A drop of iodine solution on a cut surface of a mango fruit or orange fruit juice does not produce a blue-black colour, indicating starch is absent in the fruit

Similarities between mango and orange fruits.

Presence of brightly coloured epicarp.
Presence of juicy mesocarp.
Presence of seed.
Presence of remains of style.
Presence of fruit stalk.

Differences between mango and orange fruits.

Mango fruit.	Orange fruit.
Possess one seed	Possesses many seeds
Large seed	Smaller seeds
Hard endocarp	Fleshy endocarp
Epicarp and mesocarp are not fused	Epicarp and mesocarp are fused.
One chamber or locule	Numerous chambers or locules
Beans shaped seed	Round seeds
Bilateral symmetry	Radial symmetry.

Similarities between mango and coconut fruits

Hard endocarp
Smooth epicarp
Fibrous mesocarp
One seed

The differences between mango and coconut fruits.

MANGO FRUIT	COCONUT FRUIT
Fleshy fruit	Not fleshy
Bilateral symmetrical	Radially symmetrical
No persistent calyx	Persistent calyx
Endosperm not prominent	Endosperm is prominent
Cotyledon is prominent	Cotyledon is not prominent.