Plant Biology

Form and Function

What are we learning today?

Benchmark: SC.912.L.14.7 – Relate the structure

of each of the major plant organs and tissues to physiological processes. AA

Objectives:Identify the major plant organsDiscuss the functions of the various

plant organs

What is the essential question?

Plants are complex multicellular organisms with many organs and structures that allow them to carry out all of life’s processes.

How do these organs and structures function?

What are the types of tissues found in plants?Plant tissues are

organized into three systems: Dermal tissue is like

the “skin” of a plant in that it is the outmost layer of cells.

Vascular tissue is like the plant’s “veins,” transporting water and nutrients throughout the plant, and

Ground tissue is everything else. Ground tissue is made of cells whose cell walls have different thickness.

What is vascular tissue? Forms transport

system that moves H2O and nutrients through the plant

Made up of a network of hollow connected cells Xylem, a H2O

conducting tissue,

Phloem, a food conducting tissue,

http://www.bing.com/videos/search?q=plant+tissue&FORM=HDRSC3&adlt=strict#view=detail&mid=B243CDC2669A14264988B243CDC2669A14264988

Organs of the Plant

• Plants have 3 main organs:1. Roots2. Stems3. Leaves

Root Form and FunctionTwo types of roots systems

in plants:1. Taproots2. Fibrous roots

Roots are made up of a Root cap protects the growth

zone of the root Root hairs increase water

absorption rateRoot Functions

Anchor and support the plant Absorb water and dissolved

nutrients from the soil Store food and water.

Root Structure

Root Form and Function How is a taproot different from a fibrous root? What are the two main functions of roots? How does a root prevent erosion? How are the roots of most plants adapted to perform

the major root functions? How root hairs increases the ability

of a plant to absorb water from the soil the plants grows in?

Stem Form and Function

Stem shape and growth are adaptations to the environment

Stems grow in length and thickness

Stems have several functions Transport materials between

a plant’s roots and its leaves

Support leaves and other structures

Store food and water

How do plants grow in length? Meristems are clusters of tissue

that are responsible for continuing growth throughout a plant’s lifetime.

The new cells produced in meristematic tissue are undifferentiated.

An apical meristem is a group of undifferentiated cells that divide to produce increased length of stems and roots.

What is primary and secondary growth?

Primary growth is a type ofplant growth that occurs atthe tips of roots and shoots

produced by cell divisionsin the apical meristem.

Increases length

Secondary growth is the type of growth that increases the plant’s stem width (makes it thicker).

Via the cork cambium and vascular cambium

How do plants transport water? Three processes combined to

move water up in a tree Root pressure Capillary action Transpiration

Pressure created by water entering the tissues of a root can push water upward in a plant stem.

However, root pressure does not exert enough pressure to lift water up into trees.

How do plants fight against gravity?

How does capillary action work?

H2O molecules are attracted to one another by a force called cohesion.

H2O molecules can also be attracted to other substances resulting from a force called adhesion.

H2O is then attracted to the walls in xylem, and H2O molecules are attracted to one another.

The tendency of H2O to rise in a thin tube is called capillary action.

Stem Form and Function

What are the three main functions of stems? How do the functions of a stem relate to the roots and

leaves of a plant? Describe how water is transported through a plant? What is the difference between primary and secondary

growth?

Leaf Form and Function

Main organs that carry out photosynthesis

Most leaves are flat to absorbsunlight

Leaves have small openings calledstomata (stoma) that control gasexchange and water loss. A major limitation of photosynthesis

is insufficient waterTiny structures called

guard cells control the size ofthe stomata.

Leaf Form and Function What is the function of the stomata? What is the function of guard cells? What is function of leaf veins? Would a 10 foot tree with no leaves but healthy roots

be able to move water to its top? Explain your answer. How does the thin, flat structure of leaf helps increase

the efficiency of photosynthesis? How does a leaf structure is an adaptation that allows

intake of carbon dioxide with minimal water loss?

VeinLeaf cross section

Mesophyll

CO2 O2Stomata

Seed Form and Function

Seeds are the reproductive structure that contains a plant embryo

Seeds store food that the embryo uses for germination

Seeds have a protectivecoat (Cotyledon)

Seed may contain one (monocot) or two (dicot) seed coats.

Flower Form and Function

Flower: Modified leavesReproductive structure of

angiospermsDuring pollination, pollen (the

male gamete) is transferred from the stamen to the stigma Many attract animals Others are wind pollinated

After fertilization it develops into a fruit. Aids in dispersal of seeds Protects the seed

• Draw and label the parts of the flower

Male parts:-Stamen (anther and Filament)

Female parts:-Carpel• Stigma• Style• Ovary

Cone Form and Function

Reproductive organ ofgymnosperms (“nakedseeds”) Male cones produce

sperm Female cones produce

eggs.Wind pollinatedAfter fertilization, a seed develops

Seeds are not enclosed in protective fruit.Most gymnosperms are hermaphrodites (see

picture). Why would it bear male cones on the lower branches, below the female cones?

Reproduction Form and Function How are the different part of a flower involved in

reproduction? Why is it adaptive for some seeds to remain dormant

before they germinate? Why did the development of the seed was a major

factor in the success of plants? How do the flowers of wind-pollinated plants differ

from the flowers of animal-pollinated plants? How might it be an advantage for a plant to have

many flowers together? Why might wind-pollinated plants create more

problems for allergy sufferers than animal-pollinated plants?

What is the essential question?

Plants are complex multicellular organisms with many organs and structures that allow them to carry out all of life’s processes.How do these organs and structures function?

Independent Practice: EOC workbook

• Page 78-83