Plant Biotechnology: Chapter 10

• Introduction to Plant Biotechnology is covered in Chapter 10

Introduction to Plant Propagation (10.1)

• Plant propagation involves modifying or improving plants or plant parts
• Farmers discovered controlling pollination leads in control of the resulting seed crop
• Plant breeding can involve sexual or asexual reproduction (cloning)

Flower Structure

• Complete flowers contain both male (stamen) and female (pistil) sex organs
• A seed develops when a pollen sperm nucleus reaches and fertilizes an ovule

New Gene Combinations

• Crossing-over and gene shuffling during meiosis (sex cell division) create new combinations of genetic information
• The new combination of genes is carried in sex cells to the zygote

Basic Plant Anatomy (10.2)

• Plants are multicellular organisms composed of organs and tissues and have a wide variety of organ structures
• Plant tissues are groups of similar cells with a specific function

Plant Tissue Functions

• Epidermis tissue provides covering, protection, and gas exchange on plant organs
• Meristem tissue is responsible for cell division, located in shoot and leaf buds and root tips
• Cortex tissue stores food and water, filling stems and roots
• Xylem tissue transports water and minerals in roots, stems, and leaf/flower veins
• Phloem tissue transports food and sap in roots, stems, and leaf/flower veins
• Parenchyma tissue stores food and water, and fills stems and roots
• Collenchyma tissue provides support and is found in thick-walled cells of plant organs

Section 10.2 Vocabulary

• Meristematic tissue is actively dividing tissue found in shoot buds, leaf buds, and root tips, responsible for growth
• Meristems are located at all growth tips (stems, branches, roots) and in a thin circle around the stem and root
• In plants, meristematic cells are the only cells that undergo cell division.

Plant Growth, Structure, and Function (10.3)

• Plants have specific regions where cell division can occur
• Meristems are found at each growing tip

Mitosis

• During mitosis, cells make exact copies of themselves
• Tightly wound mitotic chromosomes are visible using a microscope
• Mitosis phases include Prophase, Metaphase, Anaphase and Telophase

Seed Germination

• In dicot seed germination, the diagram shows a germinating bean seed with an enlarged radicle growing down
• The epicotyl will grow up into the leaves and stem
• The two cotyledons emerge from the seed as a food source, but then wither
• Monocot seed germination will have the coleoptile protects the emerging leaves
• Corn plants are monocots since they have only one section to the seed

Introduction to Plant Breeding (10.4)

• Alternation of generations means each sex cell gets one copy (1N) of each chromosome and, therefore, one copy of each gene
• Most genes exist in one of two or more forms (alleles)
• When the zygote (2N) forms, it receives both sets of chromosomes and genes for the two sex cells
• Depending on what was carried in the sex cells, the zygote could receive two matching alleles or two different alleles for a particular trait
• The alleles of an organism are its genotype and determine the traits expressed (phenotype)

Genotypes and Phenotypes

• The alleles of an organism are its genotype, therefore they determine the plant's characteristics or phenotypes
• Plant breeders study, predict, and manipulate crosses between flowers to produce plants of desired phenotypes

Punnett Square Analysis

• Punnett Square Analysis show the possible gene combinations when crossing specific genotypes
• Wild-type plants have dark green leaves due to at least one dominant chlorophyll production allele being either GG or Gg
• Yellow-green mutant plants have two recessive alleles, represented by a gg genotype

Evaluating Validity of Data

• The 10% Error Rule is a quick calculation of 10% of the expected value
• Standard Deviation is how if the SD is twice as large compared to another graph, then data is very dissimilar and we would have less confidence in the data collection

Ensuring Accuracy with Data

• Numerical data is used rather than with words to describe data, to make objective observations
• Multiple replications of an experiment are necessary to reflect what happens regularly

Chi Square Analysis

• Chi Square Analysis tests the Hypothesis
• X² = Σ[(Ο-Ε)²/E] where;
• O = observed number for a phenotype group
• E = expected number for a phenotype group
• Σ = the Greek letter Sigma, which represents "sum of"

Asexual Plant Propagation (10.5)

• Using breeding techniques, a plant biotechnologist produce variety in the offspring of selected parental plants
• In asexual plant propagation, identical offspring are produced by a single parent
• Methods of Asexual Plant Propagation include runners, cuttings, and PTC