Honors BiologyApril 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 25Identify 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 14.2 . We will not be performing this in class today. However, it will give you a better understanding of PH and leaf color.

(Pages 439-442)

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 orchidsthat 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.

RootsParasitic 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 feetHigh. 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 14.10

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 14.11

Find:

1. Epidermis2. Cortex3. Endodermis4. Vascular chamber5. Xylem6. Phloem

Stems: Figure 14.12

Find:

1. Epidermis2. Cortex3. Xylem4. Phloem5. Pith6. Fibrovascular bundle7. Air space8. Vascular cambium

Woody Stems: Figure 14.13

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

http://youtu.be/iWaX97p6y9U

Plant Nutrition and Transport

http://youtu.be/bsY8j8f54I0

Experiment 14.3Cross Sections of Roots, Stems,

and a leafApril 3, 2014 (page 449-451)

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 463-478

Quiz: Plant Cell identification (from Lab)