Plants: Anatomy, Growth, and Function: Test Review

Key facts

Where marks get lost

• ×Calling root hairs "tiny roots." Each root hair is an outgrowth of a single epidermal cell, not a multicellular branch root. (Plant Tissues and Structures)
• ×Mixing up xylem and phloem. Xylem carries water and minerals upward in dead, hollow cells; phloem carries sugars in living cells, and can move them either up or down depending on where they are needed. (Plant Tissues and Structures)
• ×Saying a potato or an onion bulb is a root. A potato is an underground stem (its eyes are buds), and an onion bulb is mostly fleshy leaf bases. (Plant Tissues and Structures)
• ×Classifying a plant as a monocot or dicot from one feature only. Use several features together, because individual species can break any single rule. (Plant Tissues and Structures)
• ×Computing magnification with mixed units, such as dividing a 36 mm drawing by 45 μm. Convert both sizes to the same unit first. (Plant Tissues and Structures)
• ×Saying xylem cells pump water upward. Xylem cells are dead; water is pulled up by tension from transpiration, and the energy ultimately comes from the Sun evaporating water. (Transport in Plants)
• ×Describing osmosis as solutes moving. In osmosis, water moves across the membrane toward the side with more dissolved solute. (Transport in Plants)
• ×Stating that phloem only flows downward. Phloem sap flows from source to sink, so sugar moves up to a developing fruit or growing tip and down to the roots. (Transport in Plants)
• ×Using the diameter instead of the radius in $A=\pi r^2$ when finding stomatal density or potometer volume, which makes the area four times too big. (Transport in Plants)
• ×Treating stomatal closing as a pure benefit. Closing saves water, but it also cuts off carbon dioxide, so photosynthesis slows. (Transport in Plants)
• ×Using pollination and fertilization as synonyms. Pollination is pollen landing on a stigma; fertilization is a sperm fusing with an egg inside the ovule, which happens later, after the pollen tube grows. (Plant Growth and Reproduction)
• ×Saying a shoot bends toward light because the lit side grows faster. It is the shaded side, where auxin collects, that elongates more. (Plant Growth and Reproduction)
• ×Assuming auxin always speeds up growth. In roots, the auxin concentration that stimulates shoot cells slows elongation, which is why roots bend downward. (Plant Growth and Reproduction)
• ×Thinking seeds need soil nutrients or light to germinate. Most seeds run on stored food and need only water, oxygen and a suitable temperature. (Plant Growth and Reproduction)
• ×Believing offspring from cuttings or grafts vary like seedlings do. They are clones, genetically identical to the parent plant. (Plant Growth and Reproduction)
• ×Calling succession after a forest fire primary. Fire leaves the soil behind, so it is secondary succession; primary succession starts on bare rock with no soil. (Plants, Sustainability and Society)
• ×Saying legumes fix nitrogen by themselves. The nitrogen is fixed by bacteria living in the legume's root nodules. (Plants, Sustainability and Society)
• ×Assuming a plant-derived product is automatically safe or effective. Plant compounds can be toxic, and a medicine's safe dose and effectiveness must be established by testing. (Plants, Sustainability and Society)
• ×Describing Indigenous plant knowledge as one set of practices shared by all Indigenous peoples. Knowledge is specific to each nation, such as the Three Sisters practice of the Haudenosaunee. (Plants, Sustainability and Society)
• ×Taking a 0.50 m × 0.50 m quadrat to have an area of 0.50 m². Its area is 0.25 m², so using 0.50 m² halves the density estimate. (Plants, Sustainability and Society)

Practice test

24 questions from across the unit. Each one shows the lesson it comes from.

Endless drill

Fresh numbers every time, for the calculation questions in this unit.