Plants

Plant roots have extensions called root hairs. These root hairs are important the homeostasis of the plant because

• root hairs convert minerals into glucose for immediate use by cells

• root hairs decrease the need for osmosis and diffusion in vascular tissue

• root hairs prevent water loss in leaves through transpiration and gas exchange

• root hair increase the surface area of the roots for nutrient and water absorption

A corn plant produces both male and female flowers. The male flower forms the tassel at the top of the plant and the female flower forms the ear of corn. The silk that emerge from the ear are the stigma of the female flower. Each silk leads to an ovule that can become a corn seed. Which of these must happen for corn seed to develop on the ear?

• more tassels than silks need to be present on the same plant

• pollen grains must fall from the tassels and land on the silks of the ear

• pollen must be transported from the tassel to the silk through the phloem

• the tassels must come into direct contact with the silks of the ear.

Fruits grown in hot climates are usually less sweet than those grown in cooler temperatures. High temperatures increase the rate of respiration in the plants, thus reducing the sugar quotient in some fruits. Why does increased respiration in the leaves and stems reduce the sugar content in the fruits of a plant?

• chloroplasts most from the fruits to the leaves and stems to provide energy for respiration.

• the flow of nutrients shifts from the phloem to the xylem, moving nutrients away from the fruits.

• sugars are moved from the fruits to the roots for storage,

• sugars produced in the leaves are used as an energy source instead of being stored in fruits.

Insects can kill a plant by chewing through the roots in order to reduce a plant's ability to absorb water. Which would most immediately be affected by a reduction of water uptake by roots?

• disease resistance

• seed dispersal

• sunlight absorption

• photosynthesis

An ad for a micronutrient necessary for reproduction in plants states that the micronutrients added to the soil are absorbed by the plant roots and then-

• transported to reproductive tissues by the plant's shoot system

• stored in plant stems until the flowers are pollinated

• concentrated in the roots until the plants reproductive tissues mature

• transported by the phloem to the stomata in leaves, where it attracts pollinators

Which statement would best explain why tips of a plant bend toward the light?

• water evaporated faster on the side of the plant having full light.

• light sensors in the plant tips stimulated a hormone in the shoot system

• the sylem in the root system abosrd more nutreients on the shady side of the plant

• the side facing the light has a greater chance of absorbing carbon dioxide from the atmosphere.

Cytokinines are a class of plant hormones that regulate growth by promoting cell division. Cytokinines are produced mainly in meristematic tissue, where most plant growth occurs. Which system carries Cytokinines produced in the roots to the rest of the plant?

• vascular system

• dermal system

• reproductive system

• none of these

Which of the following correctly identifies the function of each structure or group of structures in the reproduction of the plant?

• Petal-pollen production

  Stamen-pollen transfer

  Carpel-production of eggs

• Petal-attraction of pollinators

  Stamen-production of male sex cells

  Carpel-egg production and embryo development

• Petal-protection for embryo

  Stamen-Supply nourishment to embryo

  Carpel-place of embryonic development

• Petal-photosynthesis

  Stamen-production of cells that protect internal organs

  Carpel, Production of egg and sperm

Specialized leaves of a Venus Flytrap trap insects that are lured by the color and scent produced by the plant. Based on this, what functions do the specialized leaves of the Venus Flytrap perform?

• provide water to the plant and perform photosynthesis

• respond to stimuli and anchor the plant

• produce nutrients to the plant and respond to stimuli

• release pollen to insects and perform photosynthesis

Which would cause the stoma of a plant to close?

• a reduced supply of oxygen

• long periods of rainfall

• high concentrations of glucose

• little available water