HL Biology Plant Science Notes

These flashcards cover key concepts related to plant science, including plant structures, functions, adaptations, and reproductive processes.

What are the main functions of the root system in plants?

The root system anchors the plant in the soil, absorbs water and nutrients, conducts water and nutrients, and stores food.

What is the characteristic vein pattern in monocot leaves?

Veins are parallel in monocot leaves.

What type of plant cell is mainly responsible for support and has a thick secondary cell wall?

Sclerenchyma cells are mainly responsible for support and have a thick secondary cell wall.

What is the process of transpiration in plants?

Transpiration is the loss of water vapor from the leaves and stems of plants, primarily through evaporation via stomata.

What adaptations do xerophytes have for surviving in dry environments?

Xerophytes may have reduced leaves, thickened waxy cuticles, reduced number of stomata, deep roots, and specialized water storage tissues.

What is the main function of the phloem in vascular plants?

The phloem is responsible for the transport of organic compounds, primarily sugars, throughout the plant.

Describe the pressure flow hypothesis concerning phloem transport.

The pressure flow hypothesis suggests that water containing sugars flows under pressure in the phloem due to a difference in water potential, with sugars actively transported into phloem cells, causing turgor pressure that aids in translocation.

What do guard cells control in relation to the leaf's stomata?

Guard cells control the opening and closing of the stomata based on water availability and gas exchange needs.

What is the role of auxins in plant growth?

Auxins promote stem elongation and inhibit growth of lateral buds, helping plants grow towards light.

What does the term 'germination' refer to in plant biology?

Germination is the process by which seeds develop into plants, resuming growth from a dormant state.

What are the four whorls of a flower?

The four whorls of a flower are calyx (sepals), corolla (petals), stamens (male organs), and pistil (female organ).