Flowers

What is the first known angiosperm?

The first angiosperm appeared around 135 million years ago.

What are the two main groups of angiosperms?

Monocots and Dicots.

What is a characteristic of monocots?

They have one cotyledon (seed leaf).

What is a characteristic of dicots?

They have two cotyledons.

Give an example of a monocot.

Grasses, wheat, corn, or rice.

Give an example of a dicot.

Roses, clover, oaks, or daisies.

What are annuals in plant life cycles?

Plants that complete their entire life cycle in one growing season.

What are biennials in plant life cycles?

Plants that require two growing seasons to complete their life cycle, producing seeds and flowers in the second season.

What are perennials?

Plants that regrow year after year.

What are the four specialized leaves of a flower?

Sepals, petals, stamens, and carpels.

What is the role of the carpel in a flower?

It is the female reproductive organ.

What is the function of the stamen?

It is the male reproductive organ that produces pollen.

What is produced during meiosis in male gametophytes?

Four haploid (N) pollen spores.

What is pollination?

The transfer of pollen to the female portions of a flower.

What is double fertilization in angiosperms?

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

What is the purpose of the endosperm?

It is a food-rich tissue that nourishes the growing seed.

What is dormancy in seeds?

A state where the embryo is alive but not growing, allowing for dispersal and timing of growth.

What is germination?

The process where the growth of the embryo resumes and the seed sprouts into a plant.

What is vegetative reproduction?

Asexual reproduction that involves the formation of new individuals via mitosis.

What is the fruit in angiosperms?

The thickened wall of the ovary that protects seeds and aids in dispersal.

What do plants need to survive?

Sunlight, oxygen, carbon dioxide, water, and minerals.

From what did modern land plants evolve?

Water-dwelling plants similar to green algae.

What adaptations do land plants have for survival?

They draw water from soil, resist drying out, and reproduce without water.

What is the life cycle of plants characterized by?

Alternation of generations between gametophyte (N) and sporophyte (2N) stages.

What major trend occurs in plant evolution regarding gametophyte and sporophyte sizes?

Gametophyte size decreases while sporophyte size increases.

What are the first plants on land?

Bryophytes, such as mosses, hornworts, and liverworts.

What is the dominant stage in the moss life cycle?

The gametophyte (haploid) stage.

What is the function of xylem in vascular plants?

To transport water.

What is the function of phloem in vascular plants?

To transport nutrients and carbohydrates produced by photosynthesis.

What are the two groups of seed plants?

Gymnosperms and angiosperms.

What is a seed composed of?

A food supply and a plant embryo (diploid).

What is the significance of pollination in seed plants?

It allows for reproduction without the need for water.

What are gymnosperms?

The first seed-bearing plants, with seeds located in cones.

What is the role of male pollen cones in gymnosperms?

They produce male gametophytes (pollen grains).

What do angiosperms produce?

Seeds in flowers.

What happens to the ovary after fertilization in angiosperms?

It develops into fruit, which protects the seed and aids in dispersal.

What is the dominant stage in the fern life cycle?

The sporophyte (diploid) stage.

What environmental conditions favor asexual reproduction in green algae?

Good environmental conditions.

What environmental conditions favor sexual reproduction in green algae?

Unfavorable environmental conditions.

What is the significance of multicellular green algae?

They provide insight into how multicellular organisms can evolve from unicellular ones.

What is a rhizoid?

A stemlike structure in bryophytes that anchors the plant.

Why does sperm in both moss and fern life cycles need water?

Sperm needs water to swim to the egg for fertilization.

How does double fertilization benefit angiosperms?

Double fertilization allows angiosperms to save energy by not developing seeds until after fertilization occurs.

What are the cell levels of anther?

Anther is 2n (diploid)

What are the ploidy levels of ovary

ovary is 2n (diploid).

What are the cell levels for pollen grain in angiosperms

1N (haploid)

WHat are the cell levels of Ovules

2N diploid

What does male meiosis produce in angiosperms?

Male meiosis produces 4 haploid (N) pollen spores.

What are the ploidy levels of a pollen grain and an embryo sac?

Pollen grain is 1N (haploid, male gametophyte) and embryo sac is 1N (haploid, female gametophyte).

What happens to the nucleus of pollen spores during mitosis?

The nucleus of pollen spores divides to produce a tube cell and a smaller generative cell.

What does female meiosis produce in angiosperms?

Female meiosis produces 4 haploid (N) cells, of which 3 disintegrate.

What happens to the remaining cell after female meiosis?

The remaining cell undergoes mitosis, producing 8 nuclei; one nucleus becomes the egg, and seven cells form, one of which contains 2 nuclei.