Question 1

Before DNA sequence data became available, phylogenies constructed from anatomical and morphological studies of living and fossil plants often supported gnetophytes as the sister group to the angiosperms. If this hypothesis were true, and the rest of the phylogeny as depicted in your text stayed the same, which of the following statements would be TRUE?

Accepted Answer

The answer of Before DNA sequence data became available, phylogenies...

Question 2

Which group of plants contains the tallest and oldest trees on Earth?

Accepted Answer

Conifers are the group of plants that contain the tallest and oldest trees on Earth. Examples of conifers include the coast redwood, giant sequoia, and bristlecone pine.

Question 3

Gnetophytes are of great interest to plant biologists because they have many traits more typical of angiosperms, such as:

Accepted Answer

Gnetophytes are unique among gymnosperms because they exhibit double fertilization, a trait more commonly associated with angiosperms. This process involves two sperm cells; one fertilizes the egg, forming a zygote, while the other fuses with two other nuclei to form a triploid cell, which usually develops into the endosperm, a nutrient-rich tissue that supports seed development. This characteristic is a significant point of interest for plant biologists studying the evolutionary relationships between gymnosperms and angiosperms.

Question 4

Which of the following challenges that plants faced in colonizing land could be considered to have been solved by a change in the life cycle to "alternation of generations"?

Accepted Answer

By alternating between haploid and diploid phases in their life cycle, plants are able to produce haploid offspring (gametophytes) through mitotic multiplication and dispersal, without requiring external water for fertilization. This solved the challenge of relying on external water for the dispersal of gametes and allowed plants to colonize more terrestrial environments.

Question 5

Most conifers are _____, meaning that they retain their leaves throughout the year.

Accepted Answer

Conifers are mostly evergreen, which means they keep their leaves throughout the year, unlike deciduous trees that change colors and lose their leaves in autumn. Ephemeral plants live for a short period, herbaceous plants are non-woody and die down to the ground at the end of each growing season, and epiphytic plants grow on the surface of other plants without being parasitic.

Question 6

At first glance, cycads and palm trees look very similar. How are they distinguished?

Accepted Answer

The key difference between cycads and palm trees is that cycads have cones, which contain seeds, while palm trees have flowers that produce fruits containing seeds. Cycads are also gymnosperms, while palm trees are angiosperms.

Question 7

Which of the following statements is NOT true of resin?

Accepted Answer

Pine resins are not boiled down to produce a sweet syrup; instead, they are used for products like turpentine and rosin. Sweet syrups are typically derived from the sap of trees, not the resin.

Question 8

All conifers are wind-pollinated.

Accepted Answer

While many conifers are wind-pollinated, some are pollinated by insects. This shows that not all conifers rely solely on wind for pollination.

Question 9

Monocots may have first evolved in frequently disturbed environments that favor an ability to spread horizontally over unstable substrates, instead of the ability to grow tall and shade out competitors. Which of the following characteristics of monocots directly support this hypothesis?

Accepted Answer

The answer of Monocots may have first evolved in frequently...

Question 10

Symbiotic relationships with nitrogen-fixing bacteria evolved independently in ferns, cycads, and eudicots.

Accepted Answer

Studies have shown that multiple lineages of plants, including ferns, cycads, and eudicots, have independently evolved symbiotic relationships with nitrogen-fixing bacteria.

Question 11

Which of the following fruits, vegetables, or grains are produced by eudicots?

Accepted Answer

Eudicots are a group of flowering plants that have two seed leaves (cotyledons) in their seeds. Blueberries, sunflower seeds, and carrots are all produced by eudicots.

Question 12

Which of the following statements is NOT a reason that conifers are absent from the tropics and are seemingly restricted to more temperate, cooler regions?

Accepted Answer

Conifers are well adapted to drier conditions due to their efficient water transport system and can resist cavitation caused by drought, which contradicts the statement in option D.

Question 13

The fact that early diverging angiosperms with vessels did not conduct water at higher rates than early diverging angiosperms that lacked vessels supports the hypothesis that:

Accepted Answer

The answer of The fact that early diverging angiosperms with...

Question 14

Gnetophytes are more closely related to angiosperms than to other gymnosperms.

Accepted Answer

Gnetophytes are a group of gymnosperms and are more closely related to other gymnosperms like conifers than to angiosperms, which are flowering plants.

Question 15

Which group of gymnosperms present today is thought to have diverged first?

Accepted Answer

Cycads are generally thought to have diverged first among extant gymnosperms.

Question 16

Annual plants are defined as plants that:

Accepted Answer

Annual plants complete their life cycle in one growing season and die after producing seeds. They do not persist through the year as bulbs, corms, or other storage organs. While some annuals may flower every year, this is not the defining characteristic of an annual plant. They also have a vascular system with a cambium layer that allows for growth and support.

Question 17

Which of the following likely contributed to the diversification of angiosperms?

Accepted Answer

The answer of Which of the following likely contributed to...

Question 18

What can scientists study in the fossil record to learn about the distribution of grasses in the past?

Accepted Answer

The answer of What can scientists study in the fossil...

Question 19

Although it is not possible to prove that the evolutionary and ecological success of angiosperms has been and continues to be due to their xylem and reproductive structures, the current distribution of which group supports that hypothesis?

Accepted Answer

Conifers, which are gymnosperms, are less diverse and widespread compared to angiosperms. The success and dominance of angiosperms in various habitats suggest that their advanced xylem and reproductive structures may have contributed to their evolutionary advantage over groups like conifers.

Question 20

About two-thirds of human caloric intake consists of a single plant tissue type. Interestingly, a tissue of gymnosperms that plays the analogous functional role of provisioning a seed is also eaten by people. These two tissues are:

Accepted Answer

The tissue type that constitutes about two-thirds of human caloric intake is endosperm, which serves as a nutritional source for the developing embryo in seeds of angiosperms. The tissue of gymnosperms that is also consumed by people and serves a similar function is the female gametophyte or megagametophyte, which contains the haploid nutritive tissue called the prothallus. This tissue supplies nutrients to the developing embryo in the ovule of gymnosperms. Therefore, the correct answer is C (endosperm and female gametophytes).

Quiz 33: Plant Diversity