Taxonomy and Plants STAAR Review

Plant hormones serve as chemical messengers between cells and tissues. Auxin is a plant hormone that causes the cells on the shady side of a plant shoot to elongate. The response enabled by auxin is known as -

• geotropism

• transpiration

• phototropism

• photosynthesis

A flower that has both male and female reproductive structures is shown.

Which statement best describes an interaction that will allow a flowering plant to

reproduce by self-pollination?

• An anther is transferred from a filament to another filament.

• An ovule is transferred from the ovary to a petal on a different flower.

• A pollen grain is transferred from an anther to the stigma of the same flower.

• An ovary is transferred from a flower on one plant to a flower on a different plant.

Positive thigmotropism is a response in plants in which they move and grow toward an object the plant comes into physical contact with usually curling around the object.

This response of the shoot system benefits the plant by allowing the plant to -

• produce more pollen for pollinators.

• Take in more carbon dioxide to convert into glucose.

• Absorb more water to transport to the leaves.

• Reach more sunlight for photosynthesis.

Answer explanation

Plants need access to sunlight for photosynthesis. Plants grow around a structure to gain consistent access to the light.

Students studying the interaction among the reproductive parts of flowering plants write the following steps. Fill in the blanks with the correct answers.

1. 1. The ​ ​ (a)   attract pollinators.

2. 2. ​ Pollen is deposited on the ​ (b)  

3. 3. The pollen grain grows and fuses with the ​ (c)  

• petals
• stigma
• ovule

Answer explanation

Petals are responsible for attracting pollinators. Pollen is attached to the stigma to begin the process of reproduction. When pollen grows it fuses with the ovule.

Water, sugar, and other important nutrients need to be transported from one part of a plant to another. Which statement correctly describes the interaction of the root and shoot systems during nutrient transport?

• The leaves take in water and sugar, which are then transported to the rest of the plant through vascular tissues.

• The roots take in water and sugar which are then transported to the rest of the plant through vascular tissues.

• The leaves take in water and the roots produce sugar that are transported to the rest of the plant through vascular tissues.

• The roots take in water and the leaves produce sugar that are transported to the rest of the plant through vascular tissues.

Answer explanation

The job of roots is to absorb water for the plant. Leaves are where photosynthesis happens, which also means that leaves are where sugar is made.