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Plant life

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Learning goals

Characteristics of animals
* What makes plant cells different from our cells
* What molecules plants need, and what molecules they produce

Characteristics

Plants are eukaryotes

They have an organized cell structure (nuclei, and other organelles)

Animal and fungus cells are also eukaryotic.

Levin 8e/Wiley fig 8-37 w174

Plant cells have a membrane (lipid bilayer )  and a cell wall (cellulose)

Animal cells only have a cell membrane.

Plant cell has a wall adapaproject

Plant cell has a wall adapaproject

Plant cells have one huge vacuole (storage organelle)

Animal cells have a few tiny vacuoles

Plant cells have chloroplasts.

This is where photosynthesis occurs.

http://www.bbc.co.uk/education/guides/zf8nb9q/revision

Plants don’t eat food (they produce their own )

Organisms that make their own food are called autotrophs or producers

Plant parasites

Parasites are heterotrophs

(they need to get food from other sources.)

A few plants are parasites on other plants,

This is Cactus Mistletoe (Tristerix aphylla), from Chile.  This is a bright red parasitic plant. It can only live on a cactus.

Echinopsis chiloensis and Tristerix aphylla

Pic by Scott Zona. Echinopsis chiloensis + Tristerix aphylla. At Parque Nacional La Campana, Chile.

What plants need/produce

Need:

Energy from visible electromagnetic radiation (“sunlight”)

CO2 (carbon dioxide gas)

H2O (water)

Trace amount of minerals, absorbed through the plant’s roots.

Produce:

Sugars (organic molecules)

Complex carbohydrates (made from the sugars)

O2 (oxygen gas molecules)

Chemistry Photosynthesis

Family tree of plants

{ http://greatneck.k12.ny.us/gnps/shs/dept/science/krauz/bio_h/handouts_000.html }

Plant cladogram larger

Green algae

What about green algae – are they plants? Click here to find out.

Non-vascular plants: Bryophytes

Excerpted from HiddenForests.co.nz

Bryophytes are a group of small, simple, green land dwelling plants of which a few are aquatic comprising of Hornworts, Liverworts, and Mosses.

These are the largest group of land plants, which number about 25,000 different species found throughout the world. Most are found in areas which are humid and damp with a cold to moderately warm climate. They can withstand being frozen in snow without damage.

As Bryophytes are simple plants, most have no internal means for transporting water or nutrients. They are often said to have leaves – but these are not equivalent to the leaves of vascular plants. Bryophytes are mostly one cell thick. They don’t have any roots but do have filaments which anchor them down.

These plants do not produce flowers, and therefore never produce seeds. They reproduce by spore production

bryophytes

Vascular plants

Vascular plants have specialized tissues for conducting water, minerals, and photosynthetic products through the plant.

They include the ferns, club-mosses, horsetails, flowering plants, conifers and other gymnosperms.

Circulation allows the plant allows it to grow to a larger size than non-vascular plants.

Xylem carries water and inorganic solutes up toward the leaves from the roots.

Phloem carries organic solutes throughout the plant.

_ light excerpt from “Vascular plant.” Wikipedia 

Apps & animations

Flash animation showing water & nutrient transport through vascular plants

Phloem loading. Biology, Eighth Edition (Raven) Chapter 38: Transport in Plants

Seed plants

Seed plants create soils, forests, and food.

Seed-producing plants are probably the most familiar plants to most people, unlike mosses, liverworts, horsetails, and most other seedless plants which are overlooked because of their size or inconspicuous appearance.

Conifers are seed plants; they include pines, firs, yew, redwood, and many other large trees.

Other major group of seed-plants are the flowering plants, including plants whose flowers are showy, but also many plants with reduced flowers – such as the oaks, grasses, and palms.

Seeded plants are either angiosperms or gymnosperms

Classification

{ http://www.easypacelearning.com/science/plants/plants/1332-plant-classifications-of-flowering-and-non-flowering-plants }

plants3

{ https://imanshomeschool.wordpress.com/2013/05/01/plant-classification-chart/ }

plant-poster

Plant reproduction

http://www.shmoop.com/plant-biology/plant-reproduction.html

http://www.biology4kids.com/files/plants_main.html

Sample questions

Feb 2017 MCAS.  A botanist studied two groups of rice plants to determine how they are related. Both groups of plants have similar shapes, but one group has longer stalks. When the botanist cross-pollinated plants from one group with plants from the
other group, the seeds produced did not sprout or grow. Which of the following conclusions is best supported by this information?

A. The two groups are the same species because the plants have similar shapes.
B. The two groups are different species because they have differently sized stalks.
C. The two groups are different species because the seeds produced cannot
sprout or grow.
D. The two groups are the same species because the plants were cross-pollinated and produced seeds.

Learning Standards

Massachusetts Science and Technology/Engineering Curriculum Framework

Life Science (Biology), Grades 6–8.
Classify organisms into the currently recognized kingdoms according to characteristics that they share. Be familiar with organisms from each kingdom.

Biology, High School
5.2 Describe species as reproductively distinct groups of organisms. Recognize that species are further classified into a hierarchical taxonomic system (kingdom, phylum, class, order, family, genus, species) based on morphological, behavioral, and molecular similarities.

Benchmarks for Science Literacy, American Association for the Advancement of Science

Students should begin to extend their attention from external anatomy to internal structures and functions. Patterns of development may be brought in to further illustrate similarities and differences among organisms. Also, they should move from their invented classification systems to those used in modern biology… A classification system is a framework created by scientists for describing the vast diversity of organisms, indicating the degree of relatedness between organisms, and framing research questions.

SAT Biology Subject Area Test

Evolution and diversity: Origin of life, evidence of evolution, patterns of evolution, natural selection, speciation, classification and diversity of organisms.

Teaching About Evolution and the Nature of Science, National Academy Press (1998)

Biological classifications are based on how organisms are related. Organisms are classified into a hierarchy of groups and subgroups based on similarities which reflect their evolutionary relationships. Species is the most fundamental unit of classification.

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