Download biology - WordPress.com

BIOLOGY
MUHAMMAD FIKRI RIZALDI
14
• ROOT
• STEM
• LEAF
• FLOWER
• FRUIT
• SEED
Root
• Root is a part of plant that commonly found under soil and the
elongation of plant axis.
a. The structure of root
• The structure of root is composed of outer structure (morphology)
and inner structure (anatomy).
· Outer Structure
• The outer structure of root is composed of root hair and root cap
(calyptra).
1. Root hairs
• Root hairs commonly is formed near the tip of root and has short
age, as well as theEnlargement of surface of root epidermic cells.
The root hairs has function to enlarge absorption region of mineral
and water from soil. The root hair will absorb mineral and water
from soil about 95%. The result of research of experts shows that
root can make root hairs of 100 million/day.
•
•
•
•
2. Root cap (calyptra)
Root cap (calyptra) protects the tip of root that has
property very soft and easily broken.
The outer part of root cover will produce acidic liquid, that
inside is found enzyme that has function to decompose
certain substance, that are not easily penetrated the tip of
root. By that enzyme, the tip of root can penetrate wall
even very strong foundation of building. Root cap has
function too protect root cells from destruction as the
effect that root growth penetrates soil.
· Inner structure
The inner structure of root is composed on tissues that
forms four layers consecutively from the most outer layer
until the most inner layer those are epidermis, cortex,
endodermis, and central core (stele).
1. Epidermis
• Epidermis is layer that is composed of one layer of cell, it has thin
wall, and has Semipermiable property. The wall of root epidermis
forms lumps that finally can form root hairs.
2. Cortex
• Cortex is layer that composed of several cell layers that have thin
walls.
• In cortex is found intercellular chambers that has function to
gaseous exchange process. Cortex is found in the inner part of
epidermis, it has ring shape from parenchyma cells, and it has
function for food reservation.
3. Endodermis
• Endodermis is cell layer that is located between cortex and central
core. Endodermis has function to control the flow of water and
mineral salts from cortex to central core.
• In Endodermic cell is found a part of band shaped called casparian
strip . The casparian strip has function to block the passing of liquid
from soil through cell wall, so liquid flows through cytoplasm.
4. Central core (stele)
• Central core is the middle part of root that is located in inner part of
endodermis. The central core consist of pericycle and vascular
bundles (xylem and phloem). The pericycle consist of parenchyma
type cell that lies between endodermis and vascular tissue that
comes from procambium cells. In pericycle is formed branches of
root and inside pericycle of young root is found xylem tissue and
phloem tissue.
• In dicotyledon plant, woody vascular (xylem) is located in wood
part, while filter vascular (phloem) is located in the skin part of the
plant. Xylem and phloem lie in one bundle called vascular bundle.
Between xylem and phloem is found cambium that has function to
form new phloem outward and new xylem inward, so dicotyledon
plant can get enlargement growth.
• In monocotyledon plant, woody vascular (xylem) and filter vascular
(phloem) are located spreadingly . Commonly monocotyledon plant
has no cambium so monocotyledon plant doesn’t have
enlargement growth.
Difference
Monocotyledon
Dicotyledon
Root system
Fibrous
Aerial
Boundary of root end with
clyptra
clear
Not clear
Pericycle
It is consist of several cell
layer of thick wall
It is consist of one cell layer
of thick wall
Location of transportation
bundle
Xylem and phloem
alternatingly
Has collateral property,
phloem is outside, xylem is
inside
Mendulla
Exist
Not exist
Cambium
Not exist
Exist
b. The Function of Root
1. Absorbing Water and mineral salt.
Through its root hair, the root can absorb water and mineral salts
solved in soil by Osmosis. Osmosis is transfer of water molecule
from higher concentration to the lower concentration through
membrane.
The movement of water and mineral salts solved in the water from
one cell to another cell caused by the presence of root pressure
power that phuses water and mineral salts go up from woody
vascular (xylem) of root to woody vascular (xylem) of stem.
2. Sticking and Supporting Body
Root has function to stick plant body to the soil so plant can sticks
stongly in the place where a plant lives. Besides, root also has
function to support another part of plant body (organs).
3. As storage of food reservation / Sebagai penyimpan cadangan
makanan
In certain plant, such as cassava, carrot, and dahlia flower, root has
function as place to store food reservation.
4. Helping Respiration
Root can function to help respiration, because
oxygen can enter through root by diffusion.
Diffusion is transfer process of molecule from
one solution of higher concentration to the
solution of lower concentration.
STEM
• Stem is organ of path of photosynthesis
product food that is produced by leaf. Some of
that photosynthesis products are carried to
the entire part of body and some more are
stored in the stem as food reservation.
• the outer part of stem is used to identify the
kinds of plant because plant stem has
particular characteristics, such as soft stem of
green color and hard stem of chocolate color.
a. The Structure of Stem
• The Structure of stem is separated into outer structure and inner
structure. The outer structure of stem in higher level plants is
separated of outer structure of herbaceous plant (not woody) and
outer structure of woody plants. The inner structure of stem is
equal to root, that is consist of epidermis, cortex, endodermis, and
central core.
Outer Structure
1. The outer structure of stem of herbaceous plants
• The Stem of herbaceous plant commonly has characteristics : Soft,
has green color, its woody tissue is a little amount or not existing at
all, the size of stem is small, and has short age.
• The outer part of stem is thin epidermis. In epidermis is found
stomata so can happen gaseous exchange of oxygen with carbon
dioxide .
2. The outer structure of stem of woody plants
• The stem of woody plant commonly has characteristic:
It has hard stem , thick, has chocolate color, and has
long age.
• The old stem, its surface is rather rough, and in certain
region is found lenticels. Lenticel is opened lumps in
stem and relates with intercellular chamber in inner
part that has function as gaseous exchazange place in
plant.
• The young stem is equal to herbaceous stem. Both
have chlorophyll so can do photosynthesis process.
But, ability to do photosynthesis will disappear when
cork layer is formed.
· Inner Structure
1. Epidermis
• Epidermis is the outer layer so intercellular chambers are
not found. Its cell wall is rather thick and its outer layer is
covered by cuticule.
• Epidermis has function as protector layer to protect layers
inside of it.
2. Cortex
• Cortex is layer that is found in the inner of epidermis. Its
cell is round, has thin cell wall, and has big vacuole. Cortex
has function to store food in stem. Cortex consist of several
cell layers with air cavities between its cells so have
function for gaseous exchange.
• In certain plant, cortex cell wall has thickening that has
function to support or strengthening plant body.
3. Endodermis
• Endodermis is layer that is located between cortex and
central core. Commonly endodermic cells contain flour
substance grains. In stem, this layer is not too clear and
almost unites with cortex.
4. Central core/ Silinder Pusat
• Central core is the most inner layer. Inside of it is found
xylem, phloem, and medulla. Xylem and Phloem form
transport vascular bundle that is found along stem,
branch, trunk, and leaf bone.
• Xylem consist of tubes of thick walls with not smooth
walls, but spiraled to form ring or spiral. Xylem has
function to transport water and minera salt that solve
in root to the leaves.
b. Function of Stem
• Stem has main function to distribute water
and mineral salt from root to leaves and
distributing food substance of photosynthesis
products from leaves to entire part of plant.
• Besides, stem also has function as the place of
sticking of leaves, flower , and seed so easily
to struct by sunlight and it is easily happens
pollination as well s spreading of fruit and
seed.
LEAF
• Leaf is one main organ in plant. Leaf has shape
widening flat and commonly has green color
because contains chloroplast in its cells. Leaf is
found in the top part of plant and sticks in the
stem.
a. The structure of Leaf
• In leaf is found leaf bone that is the elongation
of woody vascular (xylem) and filter vascular
(phloem) that is found in the stem.
· Outer Structure
• Based on composition of leaf, leaf is separated to be simple leaf and
compound leaf
• Simple leaf is leaf that has one leaf in its stalk, while compound leaf
is leaf that has some (more than one) leaves in one of its stalk.
• Based on the shape of composition of veins, leaf is separated as
follows.
1. Pinnafitied leaf, like in mango leaves
2. Palmate leaf, like in papaya leaves
3. Bending boned leaf, like in wheat leaves
4. Lancolate leaf, like in corn leaves
Pinnafitid leaf and palmate leaf are commonly found in dicotyledon
plants, while bending and parallel boned leaves are commonly
found in monocotyledon plants.
• Based on the shape of leaf edge, leaf is separated to be entire
edged leaf, for example in jackfruit leaves, and nonflat edged leaf,
for example in rose leaves.
· Inner Structure
1. Epidermis
• Epidermis consists of top epidermis and bottom epidermis.
• Stomata that is only pound in the bottom epidermis commonly is
found in dicotyledon plant,while in monocotyledon plants,stomata
is commonly found in top epidermis and bottom epidermis.
2. Pallisade tissue (pole tissue) (xylem)
• Pallisade tissue is found under top epidermis.
3. Spongy tissue (coral flower tissue)
• Spongy tissue is located under palisade tissue.In this tissue is found
transport vascular of vein transport tissue consists of woody
vascular (xylem) and filter vascular (phloem)
b. The Function of Leaf
1. The place of Photosynthesis
2. The Place of Gaseous Exchange
FLOWER
a. The Structure of Flower
a) Sepal ( Calyx )
• Sepal is the outer part of flower that consist of connection of leaf modifications,
that is composed in one or several circles.
• Sepal has function to protect inner parts of flower.
b) Petals ( Corolla ) / Mahkota Bunga ( Korola )
• Petal is located inside Sepal. The size of petal is usually larger than its sepal and
has various colour.
c) Stamen
• Stamen is male reproduction organ that located in the middle of petal, its location
is adjacent with pistil and commonly surrounds pistil.
d) Pistil
• Pistil is female reproduction organ that is found in centre part of flower.
•
b. The Function of Flower
The main function of flower is as generative reproduction organ.
FRUIT
• Fruit is not main organ in plant. Not all plants have the fruits. Commonly
fruit develops from female reproduction organ (pistil) in seed plant.
a. The kinds of fruit
• Fruit develops from pistil, that is the part of its ovary if happens
fertilization. Fertilization is fision process of ovum with sperm inside pistil.
•
•
•
•
Based on its formation, fruit is divide into two kind, those are true fruit
and false fruit.
1. True Fruit
True Fruit that is formed by all tissue in ovary. The fruit is found in fruits of
papaya, durian, mango, tomato, and so on.
2.False Fruit
False fruit I fruit that is formed not only from its ovary, but also comes
from another parts of the flower.
The Example of false fruits is Mede guava its fruit comes from enlarging
flower stalk.
b. The structure of fruit
• Fruit is composed of seed, fruit meat, and fruit skin.
Fruit skin in unripe fruit is different with ripe fruit. In
unripe fruits, its skin tissue unites, while in ripe fruit,
fruit skin is separated into three layers, those are.
1. Outer layer (Epicarp) that is hard
2. Middle layer (Mesocarp) of thick and has meat of
fibrous
3. Inner layer (Endocarp), of thin layer or hard cell layer
c. The Function of Fruit
Fruit that inside is found seed has function as plant
embryo
SEED
•
Seed is formed from fertilization product that
happen inside ovary. Ovary is separated into two,
those are ovule packed by fruit leaves, such as
seeds of mango, rambutan, salak. And ovule that
is not packed by fruit leaves, such us seed of pakis
haji (Cycas rumphii).
• Seed is divided into 3 main parts, those are seed
ski, endosperm, and embryo (fortcoming of new
plant).
PHOTOSYNTHESIS
a. Photosynthesis Process
• Photosynthesis happens in chlorophyllose plant. Chlorophyllose plant’s leaves are contained
green pigments or colourant matter called chlorophyll.
• Reaction of Photosynthesis
b. Factors That Infuance Photosynthesis Process
• Factors that influence photosynthesis are light, chlorophyll, temperature, carbondioxide, and
water.
a) Light
• Light is required in photosynthesis process as energy source.
b) Chlorophyll
• Chlorophyll is required to absorb light.
c) Temperature
• Temperature influences enzyme the works in that photosynthesis.
d) Carbondioxide
• Carbondioxide is raw material to form glucose.
e) Water / Air
• Water is raw material in photosynthesis process.