Plant Biology Flashcards

Which plant structure stores food reserves in a seed and nourishes the embryo during germination?

Answer: Endosperm

The endosperm is a nutrient-rich tissue in seeds that provides energy and nutrients to the developing embryo during germination.

What term describes plants that complete their life cycle in two growing seasons?

Answer: Biennial

Biennials such as carrots and foxglove grow vegetatively in their first year and flower, set seed, and die in their second year.

What is the main function of the waxy cuticle on leaf surfaces?

Answer: Prevent excessive water loss

The cuticle is a layer of cutin secreted by epidermal cells that reduces transpiration by limiting water vapor loss from leaf surfaces.

Which process allows sugar produced during photosynthesis to be transported from leaves to other plant parts?

Answer: Translocation

Translocation is the movement of photosynthate (mainly sucrose) through phloem tissue from source organs (leaves) to sink organs (roots, fruits).

What is double fertilization, a process unique to angiosperms?

Answer: One sperm fertilizes the egg and a second sperm fuses with the polar nuclei

In double fertilization, one sperm cell fuses with the egg to form the zygote, while a second sperm fuses with two polar nuclei to form the triploid endosperm.

What type of symbiotic relationship exists between legume roots and nitrogen-fixing bacteria?

Answer: Mutualism

Rhizobium bacteria live in root nodules of legumes in a mutualistic relationship where bacteria fix atmospheric nitrogen and the plant provides carbohydrates.

What is photoperiodism in plants?

Answer: Response to the relative lengths of day and night

Photoperiodism is a plant's physiological response to the relative duration of light and dark periods, which controls flowering, dormancy, and other seasonal processes.