Plant Reproduction

Mitosis

Cell division producing two identical diploid cells for growth and repair

Meiosis

Cell division producing four genetically diverse haploid gametes for reproduction

Calyx

The outer whorl of a flower, made up of sepals that protect the bud

Corolla

The second outermost whorl of a flower, petals in a flower, often colorful to attract pollinators

Androecium

The second innermost whorl of a flower, stamens

Gynoecium

Innermost whorl of a flower, carpels or pistils

Carpel (pistil)

Female flower part consisting of stigma, style, and ovary

Stamen

Male flower part made up of anther and filament

Monoecious (monocot)

Plant with both male and female flowers on the same plant

Dioecious (dicot)

Plant with male and female flowers on separate plants

Pollination

Transfer of pollen from anther to stigma

Pollination syndrome

Traits of flowers that attract specific pollinators (shape, color, odor)

Nectar guide

Visual cue on flowers guiding pollinators to nectar

Cotyledon

Seed leaf that stores or absorbs nutrients for the embryo

Hilum

Scar on a seed where it was attached to the ovary

Vernalization

Prolonged exposure to cold that promotes flowering in annual winter plants

Scarification

Weakening or opening the coat of a seed to encourage germination

Cutting

Asexual reproduction using a piece of a plant to grow a completely new plant

Grafting

Joining parts of two plants to grow together as one

Senescence

Natural aging and death of plant tissues

Plumule

Develops into the shoot of the plant

Hypocotyl

Connects the cotyledon to the radicle and becomes part of the stem

Radicle

Becomes the primary root of the plant

Endosperm

Provides stored food/nutrients to support embryo growth

Cotyledon

Absorbs nutrients from the endosperm for the developing embryo

Pollination by deception

A plant attracts pollinators without offering rewards (ex: false scent or shape mimicking a mate)

Fruit - A mature ovary containing seeds

What is the difference between asexual reproduction and sexual reproduction in plants?

In asexual reproduction offspring are genetically identical to the parent, while in sexual reproduction offspring are genetically diverse because of the fusion of gametes.

What are the distinguishing features of angiosperms and gymnosperms?

Angiosperms are flowering plants that have seeds enclosed in fruit and gymnosperms are non-flowering plants that don’t have fruit and their seeds are exposed on cones.

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

A staminate flower has stamens but not carpels and a carpellate flower has carpels but no stamens.

What are the three structures that make up the carpel of a flower?

Stigma, style, and ovary.

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

Anther and filament.

How does a complete flower differ from an incomplete flower?

A complete flower has all four whorls and an incomplete flower is missing one or more whorls.

Describe the reproductive process in corn. What do the tassels represent? What do the silks represent?

Tassels are the male flowers that release pollen and the silks are the styles of female flowers that catch pollen for fertilization.

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

The generative cell divides to form two sperm cells and the tube cell forms the pollen tube for sperm delivery.

How is endosperm formed and what is its purpose?

It is formed by fusion of one sperm with two polar nuclei and it provides nutrients to the developing embryo.

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

Angiosperm seeds are enclosed in fruit, while gymnosperm seeds are exposed on cone scales.

What type of pollination is more common in angiosperms and gymnosperms?

Animal or insect pollination is more common in angiosperms and wind pollination is more common in gymnosperms.

How does self-pollination differ from cross-pollination? What are the advantages and disadvantages of each?

Self-pollination is more efficient but reduces genetic diversity and cross-pollination is less efficient but increases diversity.

How is self-pollination prevented in flowers?

Spatial separation of anthers and stigmas, male and female flowers on separate plants, flower shape, self-incompatibility genes, and temporal separation of pollen release and stigma receptivity.

Describe some mechanisms of cross-pollination.

Insect, wind, water, animal fur, body contact, and bird.

Describe the flower features that align with each type of pollinator.

Bees: bright colors, sweet scent, and landing platform. Hummingbirds: tubular flowers, red/orange, and lots of nectar. Flies: foul odor and dark colors. Butterflies: Bright colors and flat landing areas.

Describe features of flowers that are typically wind-pollinated.

Small, odorless flowers with no nectar, exposed anthers, and large feathery stigmas.

Describe the process of double fertilization.

One sperm fertilizes the egg to form a zygote and the other fuses with polar nuclei to form triploid endosperm.

What is the difference between the structure of a monocot seed and a dicot seed?

Monocot seeds have one cotyledon and a large endosperm, while dicot seeds have two cotyledons and a small endosperm.

Describe the origin of the following: simple fruit, multiple fruit, aggregate fruit, accessory fruit.

Simple fruit is from one ovary, multiple fruit is from multiple flowers, aggregate fruit is from one flower with multiple ovaries, and accessory fruit includes tissue that isn’t from the ovary.

What does a flower look like to a bee? Why don’t humans see the same thing?

Bees see ultraviolet light, which reveals nectar guides humans can’t see because they lack the photoreceptors needed to detect those wavelengths.

What is the major pollinator of the following: corpse flower, skunk cabbage, and giant water lily

Corpse flower pollinator is carrion beetles and flies, skunk cabbage pollinator is flies, and giant water lily pollinator is beetles.

What factors influence seed germination time?

Temperature, moisture, light exposure, and seed coat thickness.

What are some mechanisms of seed dispersal?

Wind, water, animals (internal), and animals (external).

Why is seed dormancy important to many plants?

It prevents germination under unfavorable conditions and increases survival chances.