PLANT REPRODUCTIONPLANT REPRODUCTION

ENDURING ENDURING UNDERSTANDINGUNDERSTANDING

• Flowers depend on seed Flowers depend on seed production and dispersal production and dispersal for their reproduction.for their reproduction.

LEARNING GOALLEARNING GOAL• I will dissect and mount the structures of

simple flowers.• I will examine a variety of seeds to discover

their dispersal mechanisms.• I will explain the function of flowers and

pollination.• I will explain how seed-dispersal mechanisms

contribute to a plant’s survival.• I will understand the origin of seeds by

investigating the reproductive systems in flowers.

DISCLAIMERDISCLAIMERThis unit is about This unit is about Plant Reproduction! Plant Reproduction!

There will be terms and words used There will be terms and words used that are…interesting.that are…interesting.

DO WHATEVER YOU NEED TO DO TO DO WHATEVER YOU NEED TO DO TO BE A MATURE SCIENTIST.BE A MATURE SCIENTIST.

LIFE ON EARTHLIFE ON EARTH• There are 5 primary groups There are 5 primary groups

of life called of life called kingdoms.kingdoms.1.1. Monera (bacteria)Monera (bacteria)2.2. Protists (single-celled)Protists (single-celled)3.3. Fungi (yeast, mushrooms)Fungi (yeast, mushrooms)4.4. AnimalsAnimals5.5. PlantsPlants

• We know that a We know that a characteristic of life is to characteristic of life is to reproduce.reproduce.

PLANT PLANT REPRODUCTIONREPRODUCTION

• Plants have sexual Plants have sexual reproduction.reproduction.

• In order to discover how In order to discover how plants reproduce, we will plants reproduce, we will investigate and study their investigate and study their structures.structures.

PLANTREPRODUCTION

VIDEO CLIPVIDEO CLIP

The ovary ovary of the flower is where the seeds develop. As we know, seeds contain an embryo, which is the living baby plant that has the potential to grow into a new plant.

Seeds start as ovulesovules, tiny preseeds in the ovary. The ovary is located at the base of the pistilpistil in the center of the flower. Inside each ovule is a single, female sex cell, the eggegg. Some plants have one ovule in the flower, like a peach or cherry flower. Other plants have hundreds of ovules in the flower, like a watermelon or a tomato flower.

Before an ovule can develop into a seed, the egg must be fertilizedfertilized. An egg is fertilized when it joins with a male sex cell, the spermsperm. The sperm cell is inside the pollen grainpollen grain. Pollen grains are produced by the plant in the anthersanthers at the tips of the stamens. The process by which pollen gets from the male anther to the female pistil is called pollinationpollination.

Pollination is complete when a pollen grain, carried by air, water, or an animal, lands on the sticky tip of the pistil, the stigmastigma. The pollen grain then germinates and grows a structure like a root that goes down the length of the pistil. It is called the pollen tubepollen tube. The sperm cell from the pollen grain travels down the pollen tube into the ovule, and penetrates the membrane of the egg cell. The contents of the two sex cells mix together, forming a single, fertilized cell. The fertilized cell is alive and has the potential to develop into a new plant.

Sexual reproductionSexual reproduction happens when a female sex cell (egg) and a male sex cell (sperm) merge to form a single cell with information from both the male and the female.

READINGREADING• We will read the article called, We will read the article called,

“FLOWER TO SEEDS” “FLOWER TO SEEDS” page page 4040

• Then answer 6 questions Then answer 6 questions about the readingabout the reading

WORD BANK• Ovary- where seeds develop

• Ovules- tiny preseeds in the ovary

• Pistil- center of the flower, ovary is located at the base (female part)

• Egg- female sex cell in the ovule

• Fertilized- ovule joins with sperm to create an egg (embryo)

WORD BANK• Sperm- male sex cell located in

pollen grain• Pollen grain- contains the sperm cell• Anthers- produces the pollen grains,

located at the end of the stamen• Pollination- the process by which

pollen gets from the male anther to the female pistil and down to the egg

• Stigma- sticky tip of the pistil

WORD BANK• Pollen tube- grows from the

pollen grain the length of the pistil and carries the sperm cell

• Sexual Reproduction- happens when a female sex cell (egg) and a male sex cell (sperm) merge to form a single cell with information from both the male and female

HOMEWORKHOMEWORK• Go home and look for, obtain, ask for, Go home and look for, obtain, ask for,

any flowers to bring in to dissect.any flowers to bring in to dissect.

• If you bring some in, come to me at 8am If you bring some in, come to me at 8am tomorrow and we will put them in some tomorrow and we will put them in some water.water.

• You may not dissect the flower you You may not dissect the flower you bring.bring.

FLOWERSFLOWERS• What are the purpose of flowers? What are the purpose of flowers?

(think of the video) (think of the video)• Many plants produce flowers. I Many plants produce flowers. I

have some examples of typical have some examples of typical flowers. You will be working with You will be working with your group to observe a flower in your group to observe a flower in detail.detail.

• First you will observe the First you will observe the complete flower, then you will complete flower, then you will dissect it to study its structures dissect it to study its structures and designs.and designs.

CD-ROMCD-ROM• Watch and learn Watch and learn

how to make a how to make a flower mountflower mount

FLOWER-MOUNT STEPSFLOWER-MOUNT STEPS1.1. Stick one end of tape to tabletop.Stick one end of tape to tabletop.2.2. Place an index card on top of the Place an index card on top of the

edge of the tape.edge of the tape.3.3. Extend the tape across the card Extend the tape across the card

(sticky side up) and tuck the (sticky side up) and tuck the other end of the tape under the other end of the tape under the card.card.

4.4. Lower the card with the tape Lower the card with the tape across it flat onto the table.across it flat onto the table.

FLOWER-MOUNT FLOWER-MOUNT FINISHING STEPSFINISHING STEPS

1.1. Slide the index card out from Slide the index card out from under the tape.under the tape.

2.2. Put the card over the tape strip.Put the card over the tape strip.3.3. Firmly press the card onto the Firmly press the card onto the

tape.tape.4.4. Carefully lift the card from the Carefully lift the card from the

table and fold the tape ends to table and fold the tape ends to the back of the card.the back of the card.