Sexual Propagation & Seed Germination Textbook pages 88 & 93

Essential Questions How does the ability to sexually produce seeds benefit a plant? What is germination and what conditions are necessary for germination to occur in a seed?

How does the ability to sexually produce seeds benefit a plant? Sexual reproduction in plants involves the union of the male pollen (sperm) with the female egg and results in the formation of a seed. Pollen + Egg = Seed

How does the ability to sexually produce seeds benefit a plant? Sexual reproduction enables a plant to produce new combinations of genetic information for more unique plants that may have the ability to be stronger. Pollen + Egg = Seeds with Genetic Variation

How does the ability to sexually produce seeds benefit a plant? The seed contains the embryo, the endosperm or cotyledon (the stored food), and is surrounded by a protective seed coat.

How does the ability to sexually produce seeds benefit a plant? The embryo plant within the seed is the result of a fertilized egg or zygote. This is a combination of the genetic information from the sperm and the egg. Sperm + Egg = Zygote (makes the Embryo)

How does the ability to sexually produce seeds benefit a plant? The combination of the genetic information is called a hybrid. Agricultural crops have been greatly improved through hundreds of years of hybridization.

How does the ability to sexually produce seeds benefit a plant? Seeds are designed to wait until the conditions are favorable to begin growth. The embryo plant is in a dormant or resting phase while inside the seed. Seeds are dormant until there are perfect conditions.

What is germination and what conditions are necessary for germination to occur in a seed? Germination is the end of the period of dormancy for the embryo plant. It occurs when the seed changes into a developing seedling. Germination = Seed grows into a Seedling

Germination = warmth, moisture, oxygen What is germination and what conditions are necessary for germination to occur in a seed? The conditions for germination are warmth, moisture, and oxygen. Germination = warmth, moisture, oxygen

This is called turgor pressure and causes the seed coat to rupture. What is germination and what conditions are necessary for germination to occur in a seed? Moisture - water enters the seed and causes it to expand and create pressure within the seed. This is called turgor pressure and causes the seed coat to rupture. Turgor Pressure = Ruptured Seed Coat

What is germination and what conditions are necessary for germination to occur in a seed? Temperature - Seeds germinate at a wide range of temperature. Some plants require very warm germination temperatures and other plants must have cooler temperatures.

What is germination and what conditions are necessary for germination to occur in a seed? Oxygen - All seeds need oxgygen to germinate and allow growth and development of the embryo plant.

Why is sexual reproduction of plants important? EXIT SLIP QUESTIONS: Why is sexual reproduction of plants important? 2) What is the definition of GERMINATION? 3) What conditions must be met for germination to occur?

HOMEWORK Write a CER summary paragraph for your Germination Cornell notes. Be sure to include a Claim, and support it with Evidence and Reasoning based on things that you learned today.

Tomorrow’s Content: Two additional mechanisms affect germination in certain plant seeds: * Stratification - a required period of cold temperature * Scarification - a mechanism that breaks down the seed coat