Honors Biology April 3, 2014 Module 14 Kingdom Plantae: Anatomy and Classification, Part 2

Lab books If you have missing assignments, see me after class.

April 3, 2014 Quiz 25 Identify the major parts of a leaf:

April 3, 2014 Quiz 25 Identify the leaf mosaics in these pictures: A. B. C.

Determine the venation of the following leaves: D. E. F. G. H.

Major Leaf Parts

A. B. C.

Determine the venation of the following leaves: D. E. F. G. H.

Leaf Color We know that most leaves are green because they contain chlorophyll. Chlorophyll is a “pigment”, but its real job is to absorb sunlight for photosynthesis. Plants cells also contain plastids. They hold pigments as well that contain starches and oils. Carotenoids are pigments that are what color?

Besides carrots and pumpkins… Most leaves have carotenoids as well. In most leaves, the green color of chlorophyll overwhelms the oranges and yellows.

Another set of pigments are Anthocyanins Depending on the PH of the leaf tissue, will yield different colors. Review Experiment We will not be performing this in class today. However, it will give you a better understanding of PH and leaf color. (Pages )

Roots Roots perform three very important functions: 1.Roots absorb water and nutrients from the plant’s surroundings and transport them to where they are need. 2.Roots anchor the plant. 3.Roots are often used as a place for food storage. (Carrots)

Most roots grow under the ground, however we see epiphytic roots of orchids that wind around a branch. Some plants have roots that grow under ground and also send out aerial roots that allow it to cling to branches that it winds around.

Roots Parasitic plants sink their roots into a host plant. These roots steal the nutrients that the host has absorbed. (mistletoe) Other plants, have roots that hold them to rough surfaces like brick walls or rough tree bark. (Ivy)

There are 2 kinds of Root systems in plants: (Figure 14.9) 1.Fibrous root system 2.Taproot When a seed begins to sprout, the first root you see is a primary root. If the primary root continues to grow and stays the main root, the plant has a taproot system. The carrot is the primary root, and it continues to grow as the plants main root.

Fibrous Roots The primary root begins branching and branching until the root system looks like an underground “bush”.

Plants need Significantly more surface area in their root system than in their leaves. The root systems of most plants are significantly larger than the part of the plant that exists above the soil. Corn usually reaches 8-10 feet High. The fibrous system if Attached end to end would reach 150 feet. The roots of Trees are generally 5-10 times longer than the tree is tall.

Longitudinal Cross Section of a Primary Root: Figure The 4 parts of a plant root: 1.Root cap: Dead, thick walled cells. It protects the root as it shoves its way down into the soil. 2.Meristematic Region: undifferentiated cells carry on mitosis. Most of the growth takes place. 3.Elongation Region: cells are beginning to differentiate into specific kinds of cells. They stretch out filling their central vacuoles with water. 4.Maturation Region: Cells are fully differentiated. Root hairs are contained here allowing it to absorb more water and nutrients from the soil.

A lateral cross section of the Maturation Region: Figure Find: 1.Epidermis 2.Cortex 3.Endodermis 4.Vascular chamber 5.Xylem 6.Phloem

Stems: Figure Find: 1.Epidermis 2.Cortex 3.Xylem 4.Phloem 5.Pith 6.Fibrovascular bundle 7.Air space 8.Vascular cambium

Woody Stems: Figure Woody stems are different from herbaceous stems, as can be seen. 1.Bark (inner and outer bark) 2.Cork cambium: This layer continually produces cork cells. These cork cells die quickly are impenetrable to water, gases, and most parasites. They form the outer bark.

Last week we looked at growth Rings…. Page 448, Paragraph 4

The Sex Lives of Nonvascular Plants: Alternation of Generation Dr Wile’s CD

Plant Nutrition and Transport

Experiment 14.3 Cross Sections of Roots, Stems, and a leaf April 3, 2014 (page ) Objective: To observe the microscopic structure of a leaf and to compare the microscopic structures of monocots and dicots stems and roots.

Homework Complete OYO questions Complete Study Guide Questions Finish Experiment 14.3 in your lab book Take Module 14 Test Begin reading Module 15: pages Quiz: Plant Cell identification (from Lab)