Plant Concept Review Guide

Chapters 29-32

Plants have a variety of uses.  Uses include: agriculture, cereals (grains), root crops, legumes (beans), fruits, vegetables, nuts, herbs, spices, and flavorings.  Humans have also devised ways to help plants and increase yield by improving fertilizers and pesticides.

Plants can also be used to medicine, clothing, dyes, fuels (ethanol), building products, landscaping, tourism, and overall happiness.

Plant ecology is centered on the ability of plants to capture the sun’s energy and convert it to food through the process of photosynthesis.  The ecology also involves plants and their interaction with the environment. 

Plants also play a vital role in helping nutrients, water, oxygen, and carbon dioxide get recycled throughout the Earth. 

Plants interact with animals as well.  Animals help out with reproduction in plants.  Examples include bees carrying pollen from one plant to another.  The bee is after the nectar but inadvertently carries the pollen.  It’s a win-win for both organisms involved.  Some plants have evolved to look like an animal.  This helps protect the plant as well as helping with plant reproduction as mentioned above.  Plants interact with microbes such as bacteria.  Some relationships are harmful, however some are beneficial.  Some bacteria help ‘fix’ nitrogen in the nitrogen cycle that the plant can absorb and use.  Plants need humans to help protect them.  Humans have destroyed natural or native plants by introducing exotic species of plants that destroy or take over the native plants.  Diseases and animals also destroy plants.  How can you help plants?

Most plants began life living in the water.  Major changes occurred when plants gained the ability to live on land.  Plants had to learn to absorb and conserve water (cuticle), reproduce without the use of water (spores, seeds, wind), and absorb nutrients from the soil. 

Two types of land plants: vascular and nonvascular.

          Vascular- having tissues that transport water and other nutrients.

          Produces seeds.

          Nonvascular- no true tissue to transport water and nutrients.  Also lacking

          roots, stems, and leaves.  No seeds, but produce spores. 

Vascular plants can be further divided into angiosperms (flowering) and gymnosperms (pine varieties).  Angiosperms have seeds enclosed in a fruit whereas gymnosperms have seeds not enclosed in fruit.  Flowers help with attracting insects and other animals for pollen transfer.

Plant life cycles are called ‘alternation of generations’.  The haploid is called the gametophyte and the diploid is called the sporophyte. 

Seed plant characteristics:

          -seed with an embryo, nutrients, and a protective coat.

          -may or may not be surrounded by a fruit.

          -may or may not be associated with flowers.

          -are dominant because the seed can lay dormant until the conditions

           for growth are right.

Monocots                                            Dicots

one cotyledon                                      two cotyledons

parallel veins                                       branched veins

scattered vascular bundles                     circular vascular bundles

flower parts in threes                            flower parts in fours or fives

Plant growth happens in meristems, regions of cell division.  Most meristematic tissue is in the root tips or found in the tips of the stems.  Primary growth occurs when roots or shoots lengthen.  Growth in diameter is called secondary growth.

Roots, Stems, and Leaves have a variety of structures that were described in your plant packet.  Make sure you review those structures.  They include: root hairs, epidermis, endodermis, xylem, phloem, stomata, guard cells, flowers and the flower parts.

Photosynthesis is the process in which plants absorb the suns energy and converts it to sugar.  Plants do this by taking in carbon dioxide and water while releasing oxygen as a byproduct. 

Fruits and seeds result from sexual reproduction.  Fruits function in helping with seed dispersal.  The fruit is actually remnants of the ovary in the plant. 

Asexual reproduction is the production of an individual without the union of gametes.  This is beneficial in plants that are well-adapted to their environment and need quick, large scale reproductive capabilities.  The downside is lack of genetic diversity which makes plants more susceptible to disease.