Wednesday, March 21, 2012

Wednesday March 21, 2012

Hi everybody!

Today we started out doing our Fast Plants lab (if you weren't here, get the data from your partner). After that, we worked in the Science Lab for the rest of class. First, we took Chapter 29 notes (and finished our notes packet), and then we just worked on our Wildland project. Here are the Chapter 29 notes (know the words in green):

  • Sap is a watery solution that moves through the vascular system (since it is sugar, it moves through the phloem)

  • Xylem - carries water and nutreients from the roots to the leaves and stems

  • Phloem - transports sugar already made (like sap) from leaves to other parts of plants

  • Plants get carbon dioxide from the air (through the stomata), minerals and water from the soil (through root hairs), and oxygen from the soil (through stomata)

  • Remember that all minerals that enter a plant root are dissolved in water (it goes through the epidermis and cortex of the root, through the plasma membrane of root cells, and into the xylem)

  • Mycorrhiza (fungi) help in absorption

  • Macronutrients - needed in large amounts (carbon, oxygen, hydrogen, nitrogen, sulfur, phosphorus, calcium, potassium, magnesium)

  • Micronutrients - needed in extremely small amounts (iron, chlorine, copper, manganese, zinc, molybdenum, boron, nickel - mainly components of enzymes)

  • Deficiencies - quality of soil affects our own nutrition

  • 3 types of soil bacteria:

  • Nitrogen-fixing bacteria - converts nitrogen in air to ammonium

  • Ammonifying bacteria - adds ammonium by decomposing organic matter

  • Nitrifying bacteria - converts soil ammonium to nitrate - plants take this up

  • Legumes (soybeans, clover, peas, alfalfa) have root nodules (contain nitrogen fixing bacteria called Rhizobium)

  • Symbiotic relationship - bacteria have a place to live and receive carbohydrates/organics from plant. Plants get ammonium ions released into soil

  • Transport of Water:

  • Pulled up plant through transpiration (loss of water vapor from plant) through the stomata

  • Cohesion - water molecules stick together, are pulled up together

  • Adhesion - water molecules adhere (stick) to cellulose molecules in walls of xylem cells

  • Molecules of water break off from the top of the "string" as they leave the leaf. String is kept tense and pulled upward as long as transpiration continues

  • No energy expenditure by plant

  • Called: adhesion-cohesion-transpiration mechanism

  • Transpiration - greatest on sunny, warm, dry, and windy days

  • Unless rehydrated, plant could eventually die

  • Leaf stomata can help plants adjust transpiration rates - controls opening by changing shape

  • Open during day and closed at night, saving water. May close during day if plant is losing water too fast

  • The Transport of Sugars:

  • Phloem sap moves in various directions in plant

  • Phloem moves sugar from a source (leaf) to a sink (root or fruit)

  • Plant hormones - control plant growth and development, affect division, elongation, differentiation of cells

  • Auxin - produced by apical meristem (at the top), stimulates growth of the shoot, causes cells to elongate

  • Cells elongate (more auxin) on dark side of stem, causes stem to bend on opposite side (toward light)

  • Requires certain concentrations - too much inhibits stem elongation

  • Usually, it inhibits roots (except in high concentrations it can elongate roots)

  • Ethylene - a gas which triggers aging responses - fruit ripening, dropping of leaves (when one apple is spoiled, it releases too much ethylene, which spoils the whole bunch)

  • Cytokinins - growth regulators, promote cell division in roots, embryos, and fruits, stimulates growth of axillary buds (branches and bushy - why cytokinins are used by growers of Christmas trees)

  • Gibberellins - stimulates elongation and cell division in stems, can influence fruit development, used in grapes

  • Abscisic Acid - slows growth (ex: seed dormancy, especially during adverse conditions), during drought causes stomata to close during wiliting, preventing further water loss

  • Photoperiods - what plants use to detect the time of year; relative lengths of day and night

  • 2 groups:

  • Long-night plants - chrysanthemums and poinsettias, flower in late summer, fall or winter, when night lengthens (also called short-day plants)

  • Short-night plants - lettuce, iris, cereal grains, flower in late spring or early summer, when night are brief (also called long-day plants)

  • Some plants are unaffected by photoperiod, like dandelions (night-neutral)


  1. Wildland project (due Tuesday, April 3rd)

  2. Study for Chapter 28-29 Quiz - TOMORROW!!

  3. EC UP 61-62 and 63-64

  4. Study for Unit 9 Test - FRIDAY!!

Next Scribe: Michael

Sunday, March 18, 2012

Friday March 16th, 2012

As usual, we started out today's class with the "Fast Plants" lab (spending about 5 minutes on it). Right after, we continued working on our "Flowering Plants" lab, which is pages 19-34 in your Unit Packet.
Fast Plants:
Just water all of your plants, measure and record your measurements (of the stem) for each plant, and add GA to the plant leaves that call for it in the lab.

Flowering Plants:
In this 2-day lab, we basically just studied the anatomy of different monocot and dicot plants, while recognizing the differenced between the two types. It is necessary for you to know what the differences are between the stems, roots, and overall appearance (to the unaided eye as well as the aided eye) between monocots and dicots.

Here's a little review of key terms for this unit:
  1. Xylem: Part of a plant's vascular system; the xylem conducts water and nutrients throughout the plant.
  2. Phloem: Part of a plant's vascular system; the phloem conducts sugars throughout a plant's system.
  3. Stomata: Slits on the underside of a leaf that allow for the exchange of gases (such as CO2 or water vapor).
  4. Pith: The soft/spongy tissue in plants (serves as a kind of storage space for plants).
  5. Angiosperm: A kind of plant that flowers and that has seeds enclosed in a carpel.
  6. Root: The part of a plant that attaches itself to the ground to give the plant support and that absorbs nutrients and water.
  7. Shoot: The part of the plant that consists of the stem, leaves, and the other parts of a plant (of which are typically above ground).
  8. Leaf: A part of a plant that is typically green and blade like that is attached in some way to the shoot of a plant.
Homework for today:
  • Work on UP p.19-34 (due 3/19)
  • UP p. 41-54 (due 3/19)
  • WILDLAND PROJECT (should finish by end of the week)
  • Yellow CH28 study guide (Due 3/19)
  • Read CH 29 (due 3/20)
Note: Unit Test is on 3/23--this week on Friday!!! STUDY :)

Thursday, March 15, 2012

March 15, 2012

Today in class like most other days we first went and measured and watered our plants. Then after doing this, we worked on UP pages 19-34 which is the flowering plants lab for the rest of the class period.

Flowering Plants Lab
  1. pages 19-21: these pages focus on the different parts of a plant including the stem, roots, leaves, and root and shoot system. Most of the answers to these questions can be found in the book and the notes that we took in class. And if someone did not get to see the roots of the plants in the classroom, they looked similar the the root system at the top of page 20
  2. pages 21-22: these pages are review of the differences of monocots and dicots
  3. page 23: this page focus on roots and many of the answers are in the notes packet and book
  4. pages 24-27: these pages dealt with the cross sections of plant roots and stems and their specific parts. Remember, monocots and dicots have differences in their root and shoot cross sections which explains the difference in looks of the cross sections. Note: we did not do the celery stalk lab
  5. buttercup root cross section -----monocot root cross section
  6. pages 28-30: these are pages dealing with dicot woody stem plants and recognizing the different parts of them. Just saying, it is much easier to answer the questions if you read the information that is given beforehand.
  7. pages 30-32: they deal with the parts of a leaf in general and there are many of the same terms that we saw earlier on in the lab.
  8. Pages 33-34: these are review questions based on the lab and are a very good source of review.

Just as a reminder, remember to label all of images as the directions say to do and label and write the magnification of all of your drawings that you viewed in the microscope.

work on UP 19-34
UP 41-54 -> due on monday
yellow chapter 28 study guide -> due on monday
wildland project
bring textbook

NEXT: Emma

Tuesday, March 13, 2012

March 13, 2012

Today We:
Measured our plants (if you missed today, get the data from your partner)
Took a quiz on Chapter 16
Completed Chapter 28 Notes
Watched a video on plants in the rainforest
Plant Growth (a bit of review):
Primary growth: lengthening
  1. Cell division- mitosis at apical meristem region
  2. Elongation- root gows longer
  3. Maturation- root hairs develop
At the very end of the meristem ther is a root cap, which protects the area of the meristem going through rapid mitotic growth.
Secondary Growth: thickening
Vascular Cambium: Arranges vasdcular bundles and gives rise to secondary phloem and xylem.
Cork Cambium: Produces cork, which is dead when mature (aka bark) and protects the stem.
How Secondary growth works: To survive, the plant must produce xylem and phloem. Xylem is on the inside of the vascular cambium (closer to the center), and phloem is on the outside. This first set of xylem and phloem is primary xylem and primary phloem. When this vascular tissue becomes old, new tissue must replace it. The vascular cambium makes a second set of vascular tissue, or secondary xylem and secondary phloem, which is now the closest set of tissue to the vascular cambium. The alive, secondary tissue (produced second) pushes the primary xylem further in, and the primary phloem further out. The phloem pushing against the cork causes it to crack, resulting in rough bark.
Why shouldn't we peel bark off trees?: Then, you are ripping off a layer of phloem, the life source for the trees. Basically, you're a tree killer.
Pollinators (vectors) Have a Mutualistic Relationship with Flowers!
1. Pollenation- the chances of fertilization, and the formation of a seed, is greatly increased
2. Seed dispersal- seeds are taken away to colonize new environments with mre resources
Pollinators: They get food!
1. Bees are attracted by scent
2. Birds are attracted by red and pink petals
Homework: Work on the project, read UP 41-54

Monday, March 12, 2012

Chapter 16 Summary

March 12, 2012
Ch 16, plants, fungi, and the move onto land

Plants are extremely important to all living things on the Earth. It porvides numerous essential things needed for survival, like food for nearly all living things, it exchanges gasses for oxygen, which is needed for us to survive, paper, building materials, shelter clothes, things like rubber, and so on. unfortunately, plants are being wiped out more than ever before in their existence, all because of people. Plants are being killed faster than they can regrow, which could cause a mass extinction worse than any other.
the kingdom of plants are eukaryotic, multicelled, and use photosynthesis as a means of getting food/energy.

stomata: pores under leaf for gas exchange
cuticle: waxy layer on leaf that help the plant reduce water loss
Lignin: hardens cell wall
In vascular system
Xylem: transports water up stem/roots
Phloem: transports food
Yhe 4 major groups of plant evolution
Bryophytes: mosses
Ferns: vascular system
Gymnosperms (means "naked seed"): coniferous trees, first seed plants
angiosperms: flowering plants

Bryophytes have flagellated spores, and the only one whith gametophytes as the more primarily seen (over sporophytes)
Need damp places to fertilize because still dont have seeds and need to disperse
Moss doesn't have lignin
12000 species, usually in tropics or temperate woodlands in the US.
first to have phloem and xylem
still no seed, sperm flagellated, so need damp environment
sporophytes dominant stage
Gymnosperms (naked seed)
have cone seeds, on dry land, can withstand harsh winters
thick cuticles and stomata, has lignin
sporophyte dominant, gametophytes are the cones
has pollen in male cones
wind carries pollen to female cones, not water
female cones contain eggs and ovaries
male cones are smaller, female cones higher on tree to help with the dispersion of seeds
dominate almost any region on earth
250000 species
supply nearly all food and fibers
better vascular system, more efficient
has flower, caused to be one of the most sucessful types of organisms ever
flower have male (stemen: anther and filament) and female (pistol/carpel: stigma, style, ovary) parts on a flower
extremely diverse, doesn't have to rely on wind or water
has double fertilization: one sperm to egg, one to a polar body which then creates a endosperm that contains a large amount of nutrients used until the plant can photosynthesize
fruit are actually matured ovaries, they help protect and disperse the seeds
Next scribe: whoever kiran said

March 12, 2012

Hi everybody!

Today in class, we started off with measuring our plants (wild-type and rosette). For the rest of class we took notes on Chapter 28. Here are the notes (you should probably know the words in purple):

  • Stems - terminal bud is at apex of stem when plant stem is growing in length

  • Axillary buds, in angle formed by a leaf and stem, are dormant

  • Terminal bud produces hormones inhibiting growth of axillary buds = apical dominance, so plant can grow up to sun

  • Axillary buds begin growing and develop into branches under certain conditions

  • "Pinching back" is when you cut off the terminal buds, so the axillary buds grow (causing the plant to be bushy)

  • 3 kinds of modified stems:

  • Runner in a strawberry plant = horizontal stem - new plants emerge from tip of runner = asexual reproduction

  • Rhizome of an iris plant = horizontal underground stems = store food, & can bud new plants (where the plant comes up)

  • Tubers are rhizomes ending in enlarged structures (potatoes). Eyes of potato are axillary buds, can grow when planted

  • Leaves - flat blades (for light collection, move with light) and petioles (join leaves to stems)

  • Celery is a big petiole

  • Some plants have a multipart cell wall:

  • Primary cell wall - laid down first

  • Secondary cell wall - deposited between plasma membrane and primary wall, more rigid for support

  • Parenchyma cells - most abundant cell, for food storage, photosynthesis, have only primary cell walls

  • Collenchyma cells - provide support in growing parts of plant, have only primary cell walls

  • Sclerenchyma cells - have thick secondary walls (only type of cell out of these 3 that has secondary walls) with lignin (wood), when mature, most are dead - rigid cells support plants

  • 2 plant vascular tissues:

  • Xylem - contains water conducting cells - move water & minerals up stem

  • Phloem - contains food conducting cells - transport sugars from leaves or storage tissue to other parts of plant

  • 3 tissue systems continuous throughout plant:

  • Dermal - covers, protects, waxy coating (epidermis - like skin)

  • Vascular - xylem and phloem, support, transport

  • Ground - bulk of young plant, fills spaces between epidermis and vascular

  • Types of ground tissue:

  • Cortex - in root, cells store food, take up water & minerals

  • Endodermis - selective barrier in cortex (remember endo = inside)

  • Pith - fills center of stem in dicots, food storage

  • Stomata - in epidermis of leaf and some stems, are tiny pores between guard cells,

  • Minimizes water loss, allow gas exchange (should be open on a cool, humid day)

  • Mesophyll - ground tissue of a leaf, for gas exchange and photosynthesis, between epidermis and vascular tissue (remember meso = middle)

  • Review double fertilization:

  • Pollination

  • Pollen form 2 sperm

  • Sperm travel through a pollen tube to ovule

  • Double fertilization occurs: one sperm fertilizes egg forming diploid zygote which becomes the embryo; the other sperm joins to form the triploid central cell, which develops into endosperm, nourishing the embryo

  • Seed formation:

  • Embryo develops cotyledons (1 in a monocot, 2 in a dicot) - organs that absorb nutrients from endosperm

  • Embryo develops into mature seed with tough protective seed coat enclosing endosperm

  • Seed becomes dormant (time for seed dispersal, favors survival for good environmental conditions) until seed germinates

  • Fruit formation:

  • Fruit = mature ovary

  • Houses and protects seeds, disperses them from parent

  • Seed germination:

  • Seed takes up water and expands, ruptures seed coat

  • Embryo resumes growth (from dormancy)

  • Embryotic root emerges (grows downwards), then shoot; a hook forms near the tip for protection

  • True leaves expand from shoot tip and photosynthesize (sorry about the picture below...I know we don't know some of the words in there but the picture is still good!)

  • Plant growth:

  • Have indeterminate growth - continue to grow as long as they live - increases exposure to sunlight

  • Finite life span - 3 examples:

  • Annuals - mature, reproduce and die in 1 year or growing season

  • Biennials - live for 2 years; flower and seed occur during second year

  • Perennials - live and reproduce for many years

  • Primary growth - lengthening

  • Meristem - cells that divide and generate new cells and tissues

We stopped on page 15 of the notes...


  1. Work on your wildland project

  2. Chapter 28 study guide due Monday 3/19

  3. Study for the Chapter 16 quiz (either tomorrow or Wednesday)

Next scribe: Emily W