1. Flowers, Fruits, and Seeds
The Structure of Flowers

2. Angiosperms and Gymnosperms
Angiosperms – flowering plants whose seeds are enclosed in an ovary, which becomes a fruit
Gymnosperms – plants whose seeds are not enclosed in a fruit; usually a conifer

3. What are Flowers? Flowers are the reproductive part of the plant
They produce fruit and seeds
One primary function: produce seeds for reproduction
Basic parts of a flower: sepals, petals, stamens, pistils
Pedicel (or peduncle) – flower stalk
Receptacle – connects the flower parts to the pedicel

4. Flower Structure and Reproduction
1. What is an angiosperm? plants that bear fruit and flowers 2. The flower attaches to what part of the plant? receptacle 3. Why are flowers brightly colored? to attract insects to help them pollinate 4. Name two mammals that might pollinate a plant. bat, mouse

5. Flower Structure and Reproduction
5. If the petals of a flower are reduced or absent, how is the plant pollinated? wind 6. The female reproductive structures are called the: pistils or carpels 7. Name the three parts of the pistil: stigma, style, ovary

6. Flower Structure and Reproduction
8. Where are the ovules stored? ovary 9. Name the two parts of the stamen: anther and filament 10. Describe sexual reproduction in plants. the pollen from an anther is transferred to the stigma; the sperm in the pollen travels to the ovary to fertilize the egg cells 11. The ovary develops into what structure? the fruit

7. Flower Structure and Reproduction
12. Define fruit. a structure that encloses and protects the seeds; enlarged ovary of a flower 13. Some flowers are not brightly colored at all, but have a very pungent odor that smells like rotting meat. How do you think these flowers are pollinated? flies 14. In many flowers, the pistils and stamens reach maturity at different times. Considering what you know about pollination, why would this be an advantage to the plant? decrease self-pollination

11. How Anther and Filament can be Attached
In A the filament is attached to the base of the anther
In B along the back of the anther
In C to a point at the back of  the anther.

12. Some types of pistils
A single pistil consisting of several fused carpels (A) and several pistils each consisting of a single carpel (B)

13. Position of Pistils

14. Ovule Attachment

16. Typical Flower Arrangement

17. Variety in Structure
Complete flower – has sepals, petals, stamen, and pistil
Incomplete flower – lacks one or more
Examples
Poinsettia - lacks petals (red “petals” are actually special leaves called bracts)
Grass family – have bracts instead of petals and sepals

18. Variety in Structure
Staminate flowers – lack pistils and have only stamens; male flowers
Pistillate flowers – lack stamens and have only pistils; female flowers

19. Staminate and Pistillate Flowers (Incomplete)
Monoecious plants – have staminate and pistillate flowers on the same plant
Example: Corn
The pollen is found in the tassels (staminate flower)
The stigma is in the silk which leads to the ovary (pistillate flower)

20. Staminate and Pistillate Flowers (Incomplete)
Dioecious plants – have staminate and pistillate flowers on different plants
Example: Ginkgo
Staminate flowers are found on male trees
Pistillate flowers are found on female trees

21. Factors that Affect Flowering
The amount of daylight, temperature, and soil fertility are some factors that can affect flowering
The chief factor for most plants is the length of daylight and night (photoperiodism)

22. Factors that Affect Flowering
Short-day plants – require days that consist of long periods of darkness
Ex: chrysanthemums, poinsettia, dahlia, aster
Long-day plants – require a period of darkness shorter than a critical length
Ex: ragweed, clover, gladiolus

23. Factors that Affect Flowering
Day-neutral plants – amount of daylight doesn’t matter
Ex: tomato, dandelion

24. Factors that Affect Flowering
Some plants are also “programmed” to open/close at certain times of the day
Ex: morning glories (open early, close by noon), four o’clocks (open around 4 p.m.), evening primrose (open after it starts to get dark)

28. Pollination and Fertilization Answers
1. What is a fruit? An enlarged ripened ovary. 2. What two functions does fruit have in regards to seeds? Protect the seeds and help to distribute them.

29. Pollination and Fertilization Answers
3. What is the difference between pollination and fertilization?
Pollination is the transfer of pollen from anther to stigma. Fertilization is the union of egg and sperm cells.
What is a hybrid?
A cross between different species of the same type of plant.

30. Pollination and Fertilization Answers
5. Why would a horticulturist desire to make a hybrid? To improve nutritional quality and improve resistance to pests and disease. 6. Between what two flower structures does pollination occur? Anther and Stigma

31. Pollination and Fertilization Answers
How are self-pollination and cross-pollination different?
Self-pollination is pollination between either the same flower or flowers on the same plant. Cross-pollination is pollination between flowers on two different plants.

32. Pollination and Fertilization Answers
How are the three types of pollen shown on pg. 53/pg 37 different from each other? Why do you think different types of pollen look different? Would this have any practical purpose?
Different depending on how plants are pollinated. Plants need to recognize their own pollen. Can only be pollinated by their own kind.

33. Pollination and Fertilization Answers
9. Explain several ways plants are specially designed to increase pollination. Smell, nectar, arrangement of stigma and stamens, decreased petals 10. What plants do only specific insects pollinate (according to the book)? Yucca flower, carrion flower, orchids

34. Pollination and Fertilization Answers
11. In flowers, where are sperm cells and egg cells found? Sperm cells – pollen, Egg cells – ovary 12. What are gametes in general? Reproductive cells

35. Pollination and Fertilization Answers
13. Explain the process of fertilization.
After pollination, pollen tube grows down the style to the ovary. The sperm cells go down the pollen tube to the ovary and unite with the egg cells.
What role do hormones play in the formation of fruits?
They cause a fruit to ripen and grow larger.

36. Pollination and Fertilization Answers
15. Explain what occurs to a fruit as it ripens. How does a ripe fruit fall from a tree? As a fruit ripens pigments cause the fruit to change color. They get softer and smell sweet. The taste also changes. The abscission layer forms at the base of the stem and “cuts” the fruit from the tree.

37. Fruit WKST Answers
Describe how each of these fruits form. Give an example of each type.
Simple fruit – one flower, one pistil;
Ex: tomatoes, peaches, beans
Aggregate fruit – one flower, several pistils;
Ex: strawberry, raspberry
Multiple fruit – form from several flowers whose ovaries fuse together;
Ex: pineapple, fig

38. Fruit WKST Answers
2. Describe the following climate-based fruit groups.
Temperate fruit – must experience an annual cold season; grow between the polar and tropical zones; most of the US
Tropical fruit – require consistently warm temperatures; near the equator
Subtropical fruit – grow between the tropic and the temperate zones; southern US, Mediterranean countries

39. Fruit WKST Answers
3. Which group from #2 would be found in Milwaukee? - Temperate 4. What is the primary function of fruits to a plant? to scatter the seeds

40. Fruit WKST Answers
5. What is agent dispersal? Give some examples. Agent dispersal occurs when an outside agent carries the seed; the agent could be an animal (depositing the seed in fecal matter or having it attached to it), the wind, or water Ex: Wind – tumbleweeds, samaras, dandelions Water – Coconut Animals – burdock, teasel, fruits

41. Fruit WKST Answers
6. What is mechanical dispersal? Give some examples. Mechanical dispersal is when a fruit bursts open and the seeds are scattered. Ex: violets, witch hazel

42. Berries
Description – entire ovary is fleshy and juicy; does NOT include most typical berries
Examples – tomatoes, grapes, cucumbers, watermelons, oranges

43. Drupes
Description – fleshy and juicy, but have an inner woody layer called a stone that surrounds the seed
Examples – peaches, plums, cherries, apricots, mangoes

44. Pomes Description – outer fleshy layer and an inner papery core
Examples – apple, pear

45. Legumes
Description – a pod encloses several seeds; not fleshy and juicy
Examples – peas, beans, peanuts

46. Samaras
Description – small dry seeds with one or two winglike structures
Examples – ashes, maples, elms

47. Nuts
Description – dry fruits with a seed enclosed in a hard covering or shell
Examples – chestnuts, hickory nuts, hazelnuts, acorns

48. Achenes Description – consists of a seed and a thin shell
Examples – sunflower; other composite flowers

49. Grains
Description – each kernel is a fruit with a seed and a shell; the shell is attached directly to the seed and is called bran
Examples – members of the grass family; corn, rice, barley, oats, rye

50. Plant Life Cycles Plants can have three different life cycles.
Annuals – one year cycle; grow, flower, die
Biennials – two year cycle; grow, become dormant, grow, flower, die
Perennials – come back each year; grow, flower, become dormant, grow, flower, become dormant, etc.

52. Seed Structure Seeds form from ovules in the ovary
Contain two main parts
Embryo (or germ in wheat) – will develop into the new plant
Seed coat – protective covering for the seed

53. Seed Structure External parts of the seed
Hilum – scar on the seed coat where the seed attached to the ovary
Silk scar – on corn, where the silk attached

55. Seed Structure Parts of the embryo
Plumule – a tiny shoot that will develop into the stem and leaves of the plant
Radicle – will develop into the root system of the plant
Cotyledon – contains stored energy for the plant to use before it sprouts
Endosperm – only in monocots; contains extra energy

59. Monocots and Dicots
All plants can be divided into monocots and dicots. Each group has four main characteristics

60. Monocots and Dicots Monocots (ex: corn) 1 cotyledon in the seed
parallel veins
petals in multiples of 3
fibrous root system

62. Monocots and Dicots Dicots (ex: bean) 2 cotyledons in the seed
branching veins
petals in multiples of 4 or 5
taproot system

64. Seed Germination Seeds are generally dormant until they germinate
Favorable conditions trigger germination to take place
Some seeds can remain viable for years, others for only a few weeks

65. How a Bean Seed Germinates
After the seed is planted, it absorbs a lot of water
The water triggers chemical changes which causes the tissues of the embryo to swell and grow

66. How a Bean Seed Germinates
The seed coat is softened by the water so the radicle and plumule can push through
During this process, energy from the cotyledons is burned by the process of cellular respiration to provide energy for the developing plant
The root grows quickly to anchor the plant

67. How a Bean Seed Germinates
The shoot grows rapidly
The cotyledons stay attached as the shoot pushes out of the ground
It provides energy and shields developing leaves from the hot sun
Once the plant can go through photosynthesis, the cotyledons shrivel up and fall off

69. Factors that Favor Germination
An adequate supply of moisture
An adequate supply of oxygen
A favorable temperature
Proper soil conditions
Sufficient sunlight

70. Challenge
Discover the horticulturist who found 300 different uses for peanuts and what three other plants he found hundreds of uses for.
This will be used for one of the extra credit questions on your test