Plants- Roots

Question 1

Functions

Answer 1

Anchor the plant in soil

Absorb water and nutrients

Some store water and carbohydrates

Question 2

Types of roots:

Answer 2

TAP ROOT – single, large, thick main vertical root with smaller lateral roots branching from it (e.g. carrot)

FIBROUS ROOT – many small, short roots, each with smaller lateral roots

Question 3

Structure

Answer 3

ROOT CAP – thick layer of cells at root tip, protect root from damage as it grows deeper into the soil
MERISTEM – located above root cap, area of rapid growth that produces new cells to increase root size

ROOT HAIRS – tiny hair-like extensions of epidermis (outer) layer, increase surface area for absorption

ROOT CORTEX – made of cells that store carbohydrates and pass water onto xylem

ENDODERMIS – inner layer of cells, separates cortex from vascular tissue
-CASPARIAN STRIP – waxy layer between cells prevents passage of materials between cells (forces materials to pass through cells before entering xylem)

VASCULAR CYLINDER – in middle of root, contains the xylem and phloem,

Question 4

Specialization

Answer 4

TUBEROUS ROOTS – lateral root used for carbohydrate storage (e.g. sweet potato)

ADVENTITIOUS ROOTS – originate from other parts of plant (e.g. from stem)

Question 5

Relationship with other species

Answer 5

MYCORRHIZA – fungus lives on roots and increases absorption for plants, plants provide carbs for fungus

NITROGEN FIXATION – bacteria in root nodules convert nitrogen gas into form usable by plant, and plant provides bacteria with carbs

STRANGLER FIG – animals deposit seeds on other trees, fig plant begins to grow on host tree, with roots growing down and “strangling” and killing the host tree

Question 6

Human Uses

Answer 6

Food – parsnips, turnips, beets, sweet potatoes, root beer

Medicines – Ipecac to induce vomiting (no longer used), kava kava for anxiety, valerian for insomnia

Erosion control – roots help to hold upper levels of soil during wind or heavy rain