A reviewer for the internal and external parts of a seed and fruit

1. SEEDS
TWOO outermost covering of seeds
1. TESTA – outermost covering
2. TEGMEN – innermost covering
 Cotyledon – modified for absorption, this is where
nutrients from the endosperm during germination of
the seed. has a special name: scutellum which
originated from latin word “scutella” which means
small shield, VERY THIN but have a very high
surface area.
 Endosperm – can only be seen in the monocot seed.
Responsible for storage of food
 Embryo – if the gametes of the male plant goes
under fertilization, it will create a zygot which will
then result to an embryo.
 Epicotyl – a part of the seedling that will point along
the embryonic shoot. A stem where everything will
go, just above the cotyledon, or will grow upward. It
is also called “seed leaves”. Has a plumule area or
the first true leaves
 Hypocotyl – this is the first part of the embryo
that emerges from the seeds. When you plant a
seed in soil, this is the first one to emerge and It
will promptly turn downward regardless of the
orientation of the seed…will grow downward.
o Gravitropism is an important plant growth
response to the environment that directs
shoots upward and roots downward,
 Radicle – the lower end of the hypocotyl, will form a
young root that anchor, absorb water and mineral,
and transform into a root. Growing plant embryo and
becomes the primary root.. Embryonic root

2. Corn seed epicotyl is a region inside the coleoptile that
form the seed and the stem
 Coleoptile - a protective sheet that covers the
epicotyl (additional in monocot)
 Coleorhiza – protective sheet for growing radicle
(additional in monocot)
 Plumule – where epicotyl is located
 Ex: beans, peanuts, and mango
SEED GERMINATION
GERMINATION
- Process by the embryo waking up from the state of
dormancy or hibernation and will take its active life. It
covers all the changes from the earliest sprouting of
the seed as it established itself as an independent
plant. A matured seed is living, but the embryo remains
dormant
5 changes that happen during germination
1. Imbibition – an example is the absorption of water
from dry seed. Will result in the swelling of the seeds. It
takes place with a great force, the seed coat will
rapture that will make the hypocotyl, radicle, and
epicotyl come out
2. Respiration – the seed of a plant adapted to life on
pant cannot germinate under water as they require
more oxygen. They obtain oxygen contained in the soil.

3. This is the reason why put under loose soil to still
obtain oxygen. When
3. Effect of life of seed germination – all plants vary is
reponse to light, the seeds that plant to light are made
of photoblastic
a. Positive photoblastic – responds to light
during germination (lettuce, tomato). They need
light for germniation
b. Negative photoblastic – does not germinate
without light
c. Non photoblastic – can germinate with or
without light
4. Mobilization of reserves (Role of growth regulators)
– during germination, the cells from the embryo will
resume metabolic activity. One of this is going through
division and expansion. The nutrient within them
(starch, proteins, fats) needs to be digested. It makes
use of the nutrients stored by respiration.
5. Development of embryo axis into seedling – the
cells from the embryo will grow and become
metabolically active. They will grow particularly in size
and begin cellular division to form a seedling.
SEED GERMINATION
EPIGEAL
- The cotyledon comes
above the ground and embryo
will resume its growth
- Example: santol, and
mungbeans
HYPOGEAL
- The cotyledon remain
underground or under
surface.the portion of the
axis that lies above the
cotyledon elongates and
pushes the plumule upward
- Example: coconut, corn and
mango seedlings
FACTORS AFFECTING SEED GERMINATION
EXTERNAL INTERNAL
- Water – dormant
seeds are
dehydrated and only
contain 6-15% of
water but eventually
become 75-95%
when matured for
metabolism (Swelling
or imbibition is the
early sign of seed
germination)
- Oxygen – necessary
for respiration which
releases the energy
needed for growth.
one of the raw
materials of cellular
respiration to
produce ATP is
oxygen and sugar
- Temperature –
protoplasm cannot
carry vital activities at
- Seed dormancy due
to internal conditions
– the embryo is not
fully mature at the
time it is shed or
imbibition. They do
not generate until it
reaches maturity.
Freshly-shedding
seeds in certain
plants do not have a
sufficient amount of
growth hormones
required for the
growth of embryos
these seeds require
some time for the
seeds to synthesize.
The viability of seeds
ranges from weeks to
many years
- Some remained
dormant because of

4. a very high or low
temperature. This
varies on the plant.
Between 25 or 30
degrees Celsius.
their impermeable
seed coatings (hindi
nadadaanan ng
water) or a lot of
group inhibitors, or
lack of nutrients.
- Example: lotus; year
of viability – 1000
years
SEED DORMANCY
- Seed dormancy or rest is the innate inhibition of
germination of a viable seed even placed in most
favorable environment for germination
REASONS FOR DORMANCY
- Immaturity of embryo
- After-ripening – seed requires a time of dry storage for
developing (wheat, oat, barley)
- Impermeable seed coat – cannot be entered by
oxygen and water
- Hard seed coat – mechanically resistant and does not
allow the embryo to grow
- Germination inhibitors – hindi pwedeng taniman ng
ibang plants for these plant releases chemicals that
may destroy other plants hormone of Atiscic acid,
phenolic acid, coumarin, cyanogenic chemicals.
Examples are apple, peach, cucurbita
DIFFERENT KINDS OF BREAKING SEED DORMANCY
NATURAL ARTIFICIAL
- Development of
growth hormones
such as auxin
- Leaching (lost) of a
germination inhibitor
- Maturation and after-
ripening of embryo
- Wakening of
impermeable and
tough seed coats –
can either by the
action of microbes,
abrasion or passing
through the digestive
tracts of animals
- Scarification – this is
the permeable seed
coats which is
ruptured by boiling
under hot water or
chipping
- Stratification – seeds
are moistened and
exposed to oxygen to
high or low
temperature
- Counteracting
inhibitor – the
germination inhibitors
are destroyed by
dipping the seeds in
Potassium Nitrate,
gibberellin, thiourea
- Shaking and pressure
– virgoursly shaked to
weaken the seed
coats
IMPORTANCE OF SEED DORMANCY
 Perennation – the ability of
the plant to survive from
one germinating season to
other germinating seasons
such as drought or winter
season.
 Dispersal – need for the
dispersion of seed.

5.  Germination under favorable conditions – they only
germinate when sufficient water is available to release
the inhibitors and soften the seed coat
 Storage – it is because of seed dormancy that makes
plants storable for years
FRUITS
- Product of pollination and fertilization
- Contains seeds inside
- Edible product of the entire gynoecium in any floral
part. Juicy, sweet and fleshy and have a color. Some
have their own aromas
- A fertilized and ripened ovary
- Pomology – study of fruits.
REGIONS OF A FRUIT
 PERICARP – fruit wall. Will differentiate into outer
exocarp, mesocarp (fleshy part) and endocarp (inner
most part
o In dry fruits, the three (exocarp, mesocap and
endocarp) is already fused into one pericarp
CLASSIFICATION OF FRUITS

6. - SIMPLE FRUIT: Fruits are derived from a single ovary
or pistil of a flower where the pericarp is fleshy and will
be differentiated into epicarp, endocarp and mesocarp
o SIMPLE DRY FRUIT – pericarp is dry and splits
open along the sutures to liberate seeds. They
can be classified into the following types
 FOLLICLE
 LEGUMEORPOD
 SILIQUA
 SILICULA
 CAPSULE
 SEPTIFRAGAL
o DRY INDEHISCENT FRUIT – dry fruit which
does not split open at maturity. It is subdivided
into
 Achene
 Cypseia
 Carypopsis
 Nut
 Samara
 Utricle
o SCIXOCARPIC FRUIT – the fruit type is intermediate
between dehiscent and indehiscent fruit. The fruit
instead of dehiscing rather split into number of
segments, each containing one or more seeds
 Cremocarp
 Carcerulus
 Lomentum
 Regma
- AGGREGATE FRUITS: derived from a single flower
(known as “etaerio”) with several pistil (female
reproductive parts). Each pistil develops into small
fruitlets and matures until it forms a single root in a
single receptacle. Aggregate fruits develop from a
single flower having an apocarpous pistil. Kada carpel
is developed into a simple fruitlets collection of simple
fruitlets cretes aggregate fruits.
- MULTIPLE OF COMPOSITE FRUITS – develop in the
whole inflourenced along with its peduncle in which
they are born. A multiple or composite fruit develops
from the whole inflorescence along with its peduncle on
which they are born. Dervived from individual flowers in
a single inflorescence

7. o Surosis – a multiple fruit developed from a
spike or spadix.the flowers are fused together
by their perial (sepal and petal) and axis or
inbetween is fleshy and juicy, the whole
inflorescence form a compact mass (ex.
Jackfruit)
o Synconus – a multiple fruits the develops from
a hypanthodium inflorescense .the receptacle
develops further and converts into a fleshy fruits
and enclosed a a number of true fruits.
Develops in a female flower
FUNCTIONS OF FRUIT
1. Edible part of the fruit is the source of food, energy for
animals
2. They are a source of many chemicals like sugar pectin,
organic acids vitamins and minerals
3. The fruit protects the seeds from unfavorable climatic
condition and animals
4. Both fleshy and dry fruits help in the dispersal of seeds
to distant places
5. In certain causes, fruit may provide nutrition to the
developing seedling
6. Fruit provide source of medicine to humans