BIO Lectures 6

How do plants get food

They are Autotroph ( produce their own food using photosynthesis )

plants are

Multicellular - Euaryotic organisms

Plants cell walls are composed of

cellulose

Plants reproduce

Sexually and Asexually

Alteration of generations occures

1. Gametophyte (n) → Makes gametes → Fertilization → Zygote (2n).

2. Zygote grows into sporophyte (2n) → Produces spores (via meiosis) → Spores grow into new gametophytes.

Gametophyte is a multicellular plant that has ………. chromosomes which produce……. via ………..

single set of chromo. , gamets via mitosis which are haploid (n)

Seed is a ……….. plant in the …….. state that are the product of ………… in …………

small embryonic, in dormancy , of sexual reproduction in flowering plants

Mature seed structure :

1-Seed coat ( testa ) 2- Embryo 3- cotyledons

The Three basic organs evolved :

Roots , Stems and leaves

Root is an

underground portion of the plant

Root External anatomy

Meristematic zone ( root cap and region of cell division )

Elongation zone

Maturation (differentation) zone

Function of the root system :

Anchoring and supporting the plant in soil / roots absorb water and nutrients / storage

The Stem is

An above ground portion of the shoot bearing leaves

The stem is divided into …. and……..

Nodes ( where leaves attach )

Internodes ( where no leaves attached )

Function of the stem

Support ( leaves, flowers, fruits )

Conduction of ( water, minerals, sugar )

Photosynthesis

Storage

Defense

The leaf is

the most important vegetative organ of the plant

Leaf functions

Photosynthesis

Gasous Exchange

Transpiration, Absorption and reproduction

Flowers are the

reproductive shoots of the agiosperm and sporo

Flowers consists of four floral organs :

sepals, petals, stamens and carpels

Fruit develops from

the ovary which protects enclosed seeds and aids in dispersing them

Fruit maybe classified as

dry : if the ovary dries at maturity

fleshy if the ovary becomes thick, soft and sweet at maturity

Plants derive most of their organic mass from

CO2 of air but they also depend on soil nutrients

Nine of the Essential elements the plants need are called

Macro nutrients because plants need them in large amounts

Macro-nutrients are

Carbon, oxygen, hydrogen, magnesium, calcium, phosphorus, sulfur, nitrogen, potassium

there are Eight Essential elements call Micro nutrients because

Plants need them in very small amounts like

Chlorine, iron magnese

Hormones are

chemical signals that coordinate different parts of an organism

Hormones control

plant growth and development

Plant hormones are

produced in very low concentration