BOTANY AND TAXONOMY LECTURE Pharmacy 14 pag Abraham Baldwin Agricultural College ABAC Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 Lesson 5 PLANT ORGANS ROOTS 1 SHOOT SYSTEM Organs Anything above the root system consists of root is called shoots Shoot system consists of stems Also is an the plant flowers and fruits if angiosperm Group of tissues that act together to perform specific function Vascular tissue xylem and phloem Ground tissue parenchyma collenchyma and sclerenchyma Epidermis and periderm Functions Photosynthesis leaves Structural support stem Transport substances vascular tissues are present in all systems Produces flowers for sexual reproduction angiosperm ROOT SYSTEM Usually below ground Dermal tissue Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 Heterotropic can t create own nutrients Roots get nutrients from the product of photosynthesis glucose that is transported by the vascular part phloem all throughout the plant especially on the roots Anchorage Absorption absorbs water and minerals needed for photosynthesis Functions they need 2L of water a day Conduction roots defuse water and will distributed all throughout the plant Storage stores a lot of energy Corn roots need a lot of water as Rootlets 2 surface area for them to further get nutrients and water Primary TapRoot First root to come out from a germinating seeds radicle where the root comes out Secondary Taproot Root arises from primary Tertiary Taproot Root arises from secondary Group of many roots There are non absorptive regions in the roots And these regions produce other roots Producing more roots is a means for them to locate water and minerals in the soil Primary root produces secondary root while secondary root produces tertiary root Root hairs are only present on certain parts of the root Root hairs are to further maximize the ROOT CAP Root Cap Thimble shaped root cap is located at the very tip of the root where it provides protection to the apical meristem Has its own meristem Cells divide actively Since the cells divide it pushes the root down further Peripheral Cells Outermost cell of roots Secretes a lot amount of Mucigel slimy is composed of sugar substance that Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 vitamins enzymes amino acids and organic acids Mucigel provides protection lubrication and helps in water and nutrients absorption SUBAPICAL REGIONS 3 Can add 0 5 to 1 5 mm per day three types of meristematic tissue Protoderm that produces the epidermis Ground meristem that parenchyma cells of the cortex Procambium that produces primary xylem and phloem produces Area of Cell Elongation located just behind the apical meristem Cells elongate several times When cells elongate they push the root tip Responsible for the increase of the length of further to the soil the root Can elongate as much as 150x its size Lengthens by primarily filling the vacuoles with water Increases 4 10 mm per day Area of Cell Differentiation Zone of cellular maturation They become specialized Responsible in increase in length and distinctive Only zone where root hairs can be seen Clearly seen on young roots Area of Cell Division Growing apex located just behind the root cap Where mitosis happens Meristematic region Can divide every 12 36 hours Can produce 20k cells each day Quiescent Center Behind the root cap Consists of 500 1000 seemingly inactive cells The cells in here divides once every 15 20 days Acts as reservoir Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 MONOCOT ROOT AND DICOT ROOT 4 Epidermis Thin cuticle Surrounds the root Outermost layer of cell 1 cell thick Cortex Type of ground tissue Formed by ground meristem Spaces between cortex cells allow water to move from soil to endodermis Consists of many layers of parenchyma Functions as food storage Endodermis Pericycle Innermost layer if cortex It controls the transport of water and mineral from cortex to xylem Cells are tightly packed together Between endodermis and phloem A primary tissue that maintains meristematic root initiation and activities Involved in lateral development secondary roots Can contribute in the appearance of Gives rise when pericycle matures to vascular cambium and cork cambium Monocot and dicot belongs to vascular plants with seeds Angiosperms Epidermis Thin cuticle Surrounds the cell Outermost layer of cell 1 cell thick Cortex Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 Type of ground tissue Formed by ground meristem Spaces between cortex cells allow water to move from soil to endodermis Consists of many layers of parenchyma Functions as food storage Innermost layer if cortex It controls the transport of water and mineral from cortex to xylem Cells are tightly packed together Endodermis Stele Pericycle Xylem phloem and pericycle Between endodermis and phloem A primary tissue that maintains meristematic root initiation and activities Involved in lateral development secondary roots Can contribute in the appearance of Gives rise when pericycle matures to vascular cambium and cork cambium 5 Stele A k a vascular cylinder Pericycle is the outermost layer of stele It occupies the central portion of root It includes all the tissues inside the cortex TYPES OF ROOTS but Endodermis does not have spaces in casparian strip It towards between Casparian strip is a strip of suberin diverts the water and minerals cytoplasm of endodermis cells has a Taproot Most dicot are taproots thick main roots that have much smaller branch roots Document shared on https www docsity com en botany and taxonomy lecture 9274013 Downloaded by kareey winniewangari432 gmail com Midterms Angel Javier BOTANY LEC SEM 01 2022 Modifications of Taproot System Storage of food Carry out Nitrogen Fixation Respiration Carrots radish potato storage taproot conical tapered on base carrot fusiform tapered on both ends radish napiform sphere swollen happens