BIO 111 - Chapter 32: Plant Reproduction

What is Mitosis? 

Cell division that makes identical cells for growth or repair

What is Meiosis? 

Cell division that makes sex cells (sperm/egg) with half the DNA

What is Calyx? 

The outermost part of a flower made of sepals that protect the bud

What is Corolla? 

The colorful petals of a flower that attract pollinators

What is Carpel (Pistil)?

The female part of a flower; includes the stigma, style, and ovary

What is Stamen? 

The male part of a flower; includes the anther and filament

What is Monoecious (Monocot)?

A plant with both male and female flowers on the same plant

(Note: "Monocot" means one seed leaf – not related to monoecious) 

What is Dioecious (Dicot)? 

A plant with male and female flowers on separate plants

("Dicot" means two seed leaves – not directly about gender) 

What is Pollination? 

Transfer of pollen from a stamen to a carpel for fertilization

What is Pollination Syndrome?

Traits of flowers that attract specific pollinators (like bees, birds, wind)

What is Nectar Guide? 

Markings on petals that direct pollinators to the nectar

What is Cotyledon? 

The seed leaf that provides nutrients to the growing plant

What is Hilum? 

The scar on a seed where it was attached to the plant

What is Vernalization? 

Cold treatment that triggers flowering in some plants

What is Scarification? 

Scratching or softening a seed coat to help it sprout

What is Cutting?

A way to grow new plants from a cut piece of a plant (stem, leaf, root)

What is Grafting?

Joining parts of two plants to grow as one combined plant

What is Senescence? 

The aging and natural death of a plant or plant part

What are at least 6 distinguishing examples of asexual reproduction in plants? 

Asexual reproduction (1 parent, identical offspring): 

1. No need for pollinators 

2. Happens faster 

3. No seeds involved 

4. Uses structures like runners, tubers, cuttings 

5. Offspring are clones 

6. Common in potatoes, onions, strawberries 

What are at least 6 distinguishing examples of sexual reproduction in plants? 

Sexual reproduction (2 parents, varied offspring): 

7. Involves pollination 

8. Slower process 

9. Produces seeds 

10. Requires male and female organs 

11. Genetic variation in offspring 

12. Common in corn, sunflowers, peas 

What are the distinguishing features of angiosperms?

Angiosperms (flowering plants): 

1. Have flowers 

2. Seeds inside fruits 

3. Broad leaves 

4. Double fertilization 

5. More diverse 

6. Example: Apple tree 

What are the distinguishing features of gymnosperms?

Gymnosperms (non-flowering): 

7. No flowers 

8. Seeds on cones 

9. Needle-like leaves 

10. No fruit 

11. Usually evergreen 

12. Example: Pine tree 

What is the difference between a staminate flower and a carpellate flower? 

1. Staminate flower: Only has male parts (stamens), no female parts 

2. Carpellate flower: Only has female parts (carpels), no male parts 

What are the three female structures that make up the carpel (pistil) of a flower? 

1. Stigma (receives pollen) 

2. Style (tube that leads to ovary) 

3. Ovary (holds ovules/seeds) 

What are the two male structures that make up the stamen of a flower?

1. Anther (makes pollen) 

2. Filament (stalk that holds the anther) 

How does a complete flower differ from an incomplete flower? 

1. Complete flower: Has all four parts – sepals, petals, stamens, and carpels 

2. Incomplete flower: Missing one or more of those four parts

What is the reproductive process in corn? 

1. Corn is monoecious (male and female flowers on the same plant) 

2. Pollen from tassels (male) is carried by wind 

3. It lands on silks (female) 

4. Each silk leads to an ovule in the ear 

5. Fertilization creates kernels (seeds) 

What do the tassels in the corn represent?

The male flowers that produce pollen 

What do the silks in the corn represent? 

The female parts (styles) that catch pollen and lead to the ovules 

What are the egg cell and central cell (endosperm) with polar nuclei in a diagram? 

1. Egg cell: Becomes the embryo 

2. Central cell (with 2 polar nuclei): Joins with a sperm to become the endosperm (feeds the embryo) 

What becomes of the two cells that make up a mature pollen grain?

1. Tube cell → forms the pollen tube 

2. Generative cell → divides into 2 sperm cells 

How is endosperm formed and what is its purpose? 

1. One sperm fertilizes the egg, the other fuses with polar nuclei → forms endosperm 

2. Purpose: Feeds the growing embryo 

How does the seed of an angiosperm differ from the seed of a gymnosperm? 

1. Angiosperm seed: Enclosed in fruit, has endosperm 

2. Gymnosperm seed: Exposed on cones, usually no fruit 

What type of pollination is more common in angiosperms? 

Animal or insect pollination (e.g., bees, birds) 

What type of pollination is more common in gymnosperms? 

Wind pollination 

How does self-pollination differ from cross-pollination? 

1. Self-pollination: Pollen from same flower or plant 

2. Cross-pollination: Pollen from a different plant 

Describe five things that prevent self-pollination in flowers? 

1. Dioecious plants – male and female flowers on different plants 

2. Different blooming times for male and female parts 

3. Flower structure makes it hard for pollen to reach own stigma 

4. Self-incompatibility genes (reject own pollen) 

5. Male and female parts mature at different times 

Describe six mechanisms of cross-pollination: 

1. Wind – pollen blows to other plants 

2. Insects (e.g., bees) – carry pollen while feeding 

3. Birds (e.g., hummingbirds) – brush pollen while drinking nectar 

4. Water – pollen floats to another plant 

5. Animals – fur carries pollen 

6. Artificial – humans transfer pollen 

Describe flower features that match each type of pollinator: 

1. Bees: Bright-colored, sweet scent, landing platform 

2. Butterflies: Narrow tubes, bright colors, weak scent 

3. Moths: Pale flowers, strong night scent 

4. Hummingbirds: Tubular, red/orange, lots of nectar 

5. Bats: Large, pale, open at night, strong smell 

6. Wind: Small, no petals, no scent, lots of light pollen 

What are features of flowers that are typically wind-pollinated? 

1. Small or no petals 

2. No scent or nectar 

3. Lots of lightweight pollen 

4. Long stamens and feathery stigmas 

5. Flowers often hang outside leaves 

What is “double fertilization”? 

1. One sperm fertilizes the egg → becomes embryo 

2. Other sperm fuses with 2 polar nuclei → becomes endosperm 
   (Happens only in angiosperms) 

What’s the difference between monocot and dicot seeds? 

1. Monocot: 1 cotyledon, parallel veins, fibrous roots (e.g., corn) 

2. Dicot: 2 cotyledons, net-like veins, taproot system (e.g., bean) 

What is the purpose of the following seed structures (plumule, hypocotyl, radicle, endosperm, cotyledon)?

1. Plumule: Becomes the shoot/leaves 

2. Hypocotyl: Connects shoot and root, becomes stem 

3. Radicle: First root 

4. Endosperm: Stores food for embryo 

5. Cotyledon: Feeds embryo (or absorbs endosperm) 

What are the origin and examples of fruit types? 

1. Simple fruit: From one ovary (e.g., apple, cherry) 

2. Aggregate fruit: Many ovaries, one flower (e.g., strawberry) 

3. Multiple fruit: From multiple flowers (e.g., pineapple) 

4. Accessory fruit: Includes parts other than ovary (e.g., apple flesh = receptacle) 

Why does a flower look different to bees? 

1. Bees see UV light, which humans can’t 

2. Flowers have UV nectar guides that direct bees to pollen 

What are the major pollinators of these plants (corpse flower, skunk cabbage, and giant water lily)? 

1. Corpse flower: Flies (attracted to smell of rotting flesh) 

2. Skunk cabbage: Flies and beetles (attracted to odor) 

3. Giant water lily: Beetles (trapped inside overnight) 

What is “pollination by deception”? 

1. Flower tricks pollinators (no reward given) 

2. Example: Orchid mimics female insect → male visits but gets no nectar 

What are four factors that influence seed germination time? 

1. Water – activates enzymes 

2. Temperature – must be suitable for growth 

3. Oxygen – needed for energy 

4. Light – some seeds need light/dark to sprout 

What are four mechanisms of seed dispersal? 

1. Wind – light seeds float/fly 

2. Water – seeds float (e.g., coconut) 

3. Animals – eaten or stick to fur 

4. Explosive – seed pod bursts 

Examples: 

5. Wind: Dandelion 

6. Water: Coconut 

7. Animals: Berry 

8. Explosive: Pea pod 

Why is seed dormancy important? 

1. Prevents germination in bad conditions 

2. Helps seed wait for right time (moisture, warmth, etc.) 

What’s the difference between botanical and consumer definitions of fruit?

1. Botanical: A fruit develops from a fertilized ovary, holds seeds (e.g., tomato, cucumber) 

2. Consumer: Sweet, edible part of a plant (e.g., apple, banana)