PLANT BIOLOGY Flashcards
- WHAT IS A LEAF
A LEAF ISA FLATTENED PORTION OF THE STEM WHICH ARISE AT THE NODE.IT IS THE TOP PHOTOSYNTHETIC ORGAN OF THE PLANT
WHAT ARE THE PROMINENT REGIONS SHOWN BY A LEAF WHEN CUT IN TRANSVERSE SECTION.
1.EPIDERMIS
2.MESOPHYLL
3.VEINS
THE REASON WHY THE THICKNESS OF THE CUTICLE VARIES WITH PLANTS IN ARID REGIONS AND THOSE IN LESS ARID ARID REGIONS
PLANTS IN ARID REGIONS HAVE THICKER CUTICLES THAN THOSE IN LESS ARID REGIONS BECAUSE IN ARID REGIONS THE RATE OF WATER LOSS IS VERY HIGH AND AS A RESULT,THE PLANTS THAT ARE IN THESE REGIONS POSESES THICKER CUTICLES IN ORDER TO REDUCE THE LOSS OF WATER THAN THOSE PLANTS IN LESS ARID REGIONS
WHAT ARE GUAD CELLS
THEY ARE SPECIALISEDEPIDERMAL CELLS THAT SURROUNDS THE STOMATA AND THEY HELP IN CONTROLLING THE OPENING OF THE STOMATA IN RESPONSE TO CHANGE IN TUGOR
HOW THE EPIDERMAL CELLS CONTROLS THE OPENING AND CLOSING OF THE STOMATA
.THE GUARD CELLS WORK IN RESPONSE TO CHANGE IN PRESSURE
. AT LOW PRESSURE THE GUARD CELLS BECOME FLACID AND STOMATA IS CLOSED
. AT HIGH TEMPERATURES ,THE GUARD CELLS BECOME TURGID(SWOLLEN) AND THE STOMATA OPENS
DIFFERNTIATIATE BETWEEN THE CELLS FOUND IN XYLEM AND THOSE FOUND IN PHLOEM
XYLEM.
1.THEY HAVE CELLS THAT ARE NORMALLY DEAD
2.THEYARE MADE UP OF HOLLOW TUBES THAT ALLOW WATER TO MOVE
PHLOEM 1.IT CONTAINS LIVING CELLS 2.IT CONTAINS SIEVE PORES WHICH HELP THE PHLOEM SAP TO MOVE FROM CELL TO CELL
DIFFERENCES BETWEEN ENDOSPER OF A MONOCOTYLEDONS AND THAT OF A DICOTYLEDONUOS SEED
MONOCOTS
1.THE COTYLEDONS DOES NOT ABSORB THE ENDOSPERM BUT TRANSFERS NUTRIENTS FROM IT DURING GERMINATION TO THE NON LEAFY PART OF THE EMBROY
DICOTY EMBROY
IN DICOT EMBROY THE COTYLEDON BECOMS THICKER AND FLESHY AS THEY ABSORB THE ENDOSPERM
WHAT IS EPICOTYL AND HYPOCOTYL
EPICOTYL IS THE VERY SHORT PART OF THE STEM ABOVE THE COTYLEDONS
HYPOCOTYL IS THE PART OF THE STEM BELOW THE EPICOTYL
NAME THE COMPONENT THAT MAKE UP A SEED
- PLANT EMBRYO
2.STORED FOOD
3.SEED COAT
COMPARE THE STEM’S EPIDERMIS AND THE LEAF’S EPIDERMIS IN TERMS OF THEIR STOMATA
THE EPIDERMIS OF THE STEM IS THE TRANSPORT UNICELLULAR LAYER WHICH CONTAINS STOMATA BUT LESSER THAN THOSE FOUND IN LEAVES
what are the components of the plant body
1.the root system
2.the shoot system
what are the features of the root system
1.the root system is ususally found underground
2.it anchors the plant in the soil
3.it absorb water and nutrients
4.it conducts water and nutrients
5.it stores food
what are the features of the shoot system
1.it is usually found above the ground
2.it elevates the plant above the ground
3.it plays a major role in photosynthesis
4.it plays a major role in reproduction and dispersal
5.it plays a major role in food and water conservation
whatis a leaf
a leaf is any flattened green outgrowth from the stem of a vascular plant
what are the functions of a leaf
1.it is the main structure responsible for photosynthesis
2.it provides stomata for gaseous exchange
3.it serves as the main channel for transpiration
4.some leaves are caple for storing food eg.Onions
5.some leaves are used for vegetative propagationsuch as bryopyllum
what is the primary function of the leaf
it main function is for photosynthesis
what are the major functions of the leaf
1.for photosynthesis
2.transpiration
3.for gaseous exchange