Questions and Answers of Botany An Introduction To Plant Biology

What are alpha-tubulin and beta-tubulin? When they aggregate, what do they form? What structure in dividing cells is made with this substance (Figure 3-27)? Algal, fungal, and animal cells move with
What is the role of dictyosomes in cell metabolism? What is their forming face? Their maturing face?
Draw a “typical” plant cell and include all of the organelles mentioned in this chapter. Most cells have specialized functions and increased proportions of certain organelles. How would you
Examine Figures 3-32 to 3-34. What types of substances occur as storage products in plant cells?FIGURE 3-32FIGURE 3-34
Describe how material is brought to a dictyosome. What happens to material while it is in a dictyosome, and how is it released? What are some of the things that might happen to it after it is
Many animals and algae have cells with flagella, but do any plants have flagella? For example, do fern cells or moss cells have flagella?
How do microtubules act as a cytoskeleton? Are there times when they are particularly abundant? What are centrioles, basal bodies, and flagella?
What chemical do clams use to make strong shells? What do we use for our bones? Do plants use either of these chemicals in the construction of strong cell walls? What problem would plants have if
What are the extremely fine holes that interconnect plant cells? What is the name of the especially thin areas of walls where these holes are particularly common (Figure 3-37)?Figure 3-37 Cell
In cell walls, adjacent, parallel cellulose molecules crystallize into an extremely strong _________________________ 10 to 25 nm wide. These are bound together by polysaccharides called
What are the most abundant components of a plant cell wall? How do the components interact, and how are they arranged with respect to each other? What are the symplast and the apoplast in plants?
What is the type of cell wall present in all plant cells? What is the type present in certain cells that must be unusually strong?
What is an intercellular space? Diffusion through a gas-filled space is approximately ________________times faster than through a liquidfilled space. Living cells deep inside a bulky object such as
In a woody plant such as a tree, which parts have cells that live only briefly and die quickly? Which parts have cells that live for several years?
Table 4-2 gives the number of chromosomes in a haploid set of chromosomes. What is the lowest number in the table? What is the highest number? Most cells in plants are diploid, having two sets of
Some cells never stop dividing. Give two examples of cells like this.
Examine Table 4-1. How many hours does the cell cycle last in the root tips of corn and in onion? Which plant has cells that divide more quickly? How many cell cycles could corn and onion roots
What are the main activities of a cell while it is in G1 phase? What kinds of organisms have short G1 phases, and how long does a short G1 phase last? What kinds of organisms have long G1 phases, and
What is the main activity of the S phase of the cell cycle? What does “S” stand for?
What are the four phases of the cell cycle? What is the principal activity in the cell during each phase? Can any phase be eliminated or bypassed?
Why is mitosis called duplication division and meiosis called reduction division? What is reduced and what is duplicated: chromosomes, number of chromosomes, or number of sets of chromosomes?
What does it mean when chromosomes are said to condense during prophase of mitosis? How long are chromosomes after condensation is complete? How big is a typical dividing cell in a root or shoot? If
What is the name of the set of microtubules that pull chromosomes apart? What is the name of the attachment point between microtubules and chromosomes? What is the name of the ends of the cells where
What is a metaphase plate? What is duplicated at the end of metaphase? When this is duplicated, chromatids become free of each other. How many chromatids are there per chromosome in prophase? How
Imagine a nucleus that has 10 chromosomes. How many chromosomes does it have before prophase begins? How many chromosomes does each daughter nucleus have after telophase has been completed? How many
What are the four phases of mitosis, and what is the principal activity in the nucleus during each phase?
Draw a single, imaginary chromosome as it would appear just as mitosis is ending. Now describe what happens to it during interphase and then during mitosis. Be especially careful to consider how many
How does cytokinesis occur in plants? Which organelle produces vesicles that fuse to form the cell plate? What membrane is transformed into new plasma membrane?
Many people consider algae to be plants even though algae do not have roots, stems, and leaves, but in many algae, cell division is different from that in true plants. Do most algae have a
Sex cells are also called ____________________. If a species has males and females (not all species do), males produce sex cells ____________________ called cells, and females produce sex cells
How many sets of chromosomes does each sperm cell carry? How many does each egg cell have? Gametes such as sperm cells and egg cells are said to be (circle one: diploid, haploid). After a sperm and
If a plant has diploid cells with 20 chromosomes in each nucleus, how many chromosomes does each of its gametes have? What is the name of the division that reduces the number of chromosomes from 20?
What are the five stages of prophase I, and what is the principal activity of the nucleus and chromosomes during each stage?
Are there any types of organisms that do not need to take in energy and raw materials from their environment? Discuss the source of energy for plants as opposed to animals; describe some of the raw
______________________ is the central metabolism by which plants acquire energy; it occurs only when ______________________, ____________________, and ___________________ are present.
Each plant receives a great deal of information from its parents by means of the DNA in which two cells? Describe the types of information that plants receive from the environment. Why is it that
The activity of the roots of a plant must be coordinated with the activity of leaves. Describe how this occurs. What type of information molecule is used?
Which three groups of plants are referred to as bryophytes? They differ from all other plants in two main features; name the features.
Which group of plants does the term “angiosperm” refer to? What are the three main subgroups of angiosperms? Do angiosperms have vascular tissue? Do they have seeds? In conifers, seeds develop
Evolution by natural selection causes organisms to become more adapted to their environment. Is the environment uniform across all of Earth? Does the environment change with time? Considering this,
Have North and South America always been connected by Central America? Once the two continents joined, plants and animals could move from one to the other; animals can walk, fly or swim, but how does
The concept of biosphere was touched on only briefly in this chapter, but you have many resources in this book and online to explore this concept. What are some of the geological and biological
Plants and animals usually battle each other; describe why and how this occurs. Once animal-pollinated flowers evolved, a new type of plant– animal interaction was possible; describe it. How is it
Earth is constantly changing, and so are all organisms as they evolve. But despite so much change, it is possible to study and understand life because several things are always constant; what are
In plants, each cell consists of a box-like _________________________ surrounding a mass of _______________, which in turn contains its own smaller parts, the __________________________.
In Table 3-1, the size of water-conducting vessel cells in oak are______________ _ _______________________. Each millimeter contains 1,000 μm. Approximately how many of these cells could be laid end
Figure 3-1 is a light micrograph of a leaf cell, and it is typical of what you might see if you were to examine a moss leaf. What two cell structures can you see?Figure 3-1
Collenchyma is plastic, but sclerenchyma is elastic. What does “elastic” mean? If you stretch or deform an elastic object, will it keep its new shape or snap back to its original shape? As an
Examine Figure 5-6A and 5-6B. Why do most parenchyma cells shown in Figure 5-6A lack nuclei, whereas most shown in Figure 5-6B do have nuclei? In the geranium for Figure 5-6A, did the real cells lack
Early angiosperms diversified into several groups that are now known as,____________ _____________, and _________________________. Name three examples of plants within each line of evolution.
An herb has only a primary plant body. That means it has roots, stems, and leaves, but it never becomes _________________________ and covered with _________________________.
In general, animals have _________________________ growth with a fixed size and number of organs, whereas plants have _________________________ growth with no set size and any number of organs. Which
What are the important differences between parenchyma, collenchyma, and sclerenchyma cells?
What is the special name of photosynthetic parenchyma cells? Which organelle is especially abundant in these? How does wall thinness affect carbon dioxide and light?
It was previously stated that parenchyma cells are relatively inexpensive to build. What does that mean? How does this relate to most leaves being soft?
Like clay, walls of collenchyma exhibits plasticity. Does that mean it can or cannot be stretched? If a tissue is supported by collenchyma, can it still grow?
What are the two types of mechanical, nonconducting sclerenchyma (Table 5-3)? Which tends to be flexible and useful in wood? Which tends to be brittle and inflexible, useful in “pits” and
How does collenchyma support a tissue? Would it work if the tissue did not have parenchyma also? What happens if the tissue is not turgid (does not have enough water)?
Fibers and sclereids have secondary walls that are so thick and tough that the cell cannot grow. If that is true, how do fibers and sclereids grow to their mature size and shape? Do they have a
Imagine a leaf of a palm tree. When it is fully grown, it must have sclerenchyma to support its size and weight. Do you think it has any sclerenchyma when it is tiny and just starting to grow? Would
Figure 5-13A shows two types of buds. What are the two types and how do they differ?Figure 5-13A (A) Terminal bud Axillary buds
Technically, the _________________________ is an axis, whereas the _________________________ is the _________________________ plus any leaves, flowers, or buds that might be present.
The point where a leaf is attached to a stem is called a _________________________. Just above this point is an _________________________ bud.
After a leaf falls off a stem, it leaves a _________________________ just below the axillary bud.
What is phyllotaxy? Corn and irises have two rows of leaves. This is known as _________________________ phyllotaxy.
When you look at a head of cabbage or lettuce, what are you seeing? Where is the stem? What about when you look at an onion? What are you seeing and where is the onion’s stem?
Describe each of the following types of specialized shoots. Be certain to account for modifications of the leaves, internodes, and orientation of growth: stolon, rhizome, tuber, bulb, corm, and
Many scientific words are also ordinary English words. If you read that a plant has a bulb or a tuber, can you always be certain exactly what the botanical structure is?
What is the outermost surface of an herbaceous stem? The outer walls of this layer are encrusted with a chemical made up of fatty substance that makes the wall impermeable to water. What is the name
A stoma allows carbon dioxide to pass through the epidermis. What is the name of the two cells that control the opening and closing of a stoma? What is the name of the hole itself that carbon dioxide
What is the technical term for a plant hair? Plant hairs make it difficult for animals to do certain things. Name three activities that are more difficult for an animal because of a hairy leaf.
What is the name of the region of cells between a stem’s epidermis and its set of vascular bundles? This is usually a compact parenchyma tissue, but in some aquatic angiosperms that live submerged
All flowering plants have two types of vascular tissues, _________________________, which conducts water and minerals, and _________________________ , which distributes sugars and minerals. Are
As a young xylem cell matures into a tracheary element, it first must enter _________________________ and stop _________________________. It is initially a small _________________________ cell, but
List the five types of secondary wall deposition that can occur in tracheary elements. Which two types are most characteristic of protoxylem? What is the selective advantage of vessel elements over
Consider tracheary elements with annular thickening (annular secondary walls) and those with pitted walls. Which is weaker? Which has a large percentage of its primary wall free of secondary wall and
Tracheids obtain water from _________________________ below them and pass it on to _________________________ above. As water passes into or out of a tracheid, it passes through a
If each tracheid is 1 mm long, how many pit-pairs and pit membranes will a water molecule pass through in a plant 1 m tall? Is this a significant amount of friction?
Which evolved more recently, tracheids or vessel elements? Do nonangiosperms such as conifers and ferns have vessel elements? Do flowering plants (angiosperms) have tracheids? Vessel elements?
Like xylem, phloem has two types of conducting cells, _________________________ and _________________________. The term “_________________________ _________________________” refers to either one.
What is the name of the holes that interconnect conducting cells in phloem, and what are groups of these holes called?
Sieve tube members differ from sieve cells by having very large sieve pores on their end walls, much larger than the ones on their side walls. What is the name of these end-wall sieve areas with big
Sieve elements (both sieve cells and sieve tube members) lose their nuclei during development, but they must remain alive. What is the name of the cell associated with sieve cells? The one associated
During differentiation of a young cell into a sieve tube member, what are some changes that occur in the cell wall and the cytoplasm? How long do most sieve tube members live after they become mature?
Describe plasmodesmata, pits, perforations, and sieve pores. Which connect living cells? Which connect nonliving cells? Which occur in secondary walls?
All vascular bundles are _________________________. That is, each contains both xylem and phloem. The xylem of a vascular bundle is _________________________ xylem because it is part of the primary
Stems grow longer by creating new cells at their tips, in regions known as _________________________. Below this region, in the subapical meristem, the very first primary xylem to appear is called
Look at Figure 5-42. The top three rows are labeled “Primary growth” because these are found in the primary plant body, the body of an herb. The third row of the figure has five boxes with the
In the apical and subapical region, there are cells that will later give rise to epidermis and other tissues, but they are not yet mature enough to call them epidermis, and so on. What are the terms
Describe the arrangement of tissues seen in a stem cross-section; consider monocots separately from the other angiosperms. Is the arrangement different in a stolon than in a rhizome, tuber, or corm?
If you live to be 100 years old, how many sets of organs will you have during your lifetime? How many hearts, stomachs, and livers? If a plant lives to be 100 years old, how many sets of leaves will
Leaves carry out many roles in a plant’s life. Give examples of leaves that do the following:a. Provide protectionb. Provide supportc. Provide storaged. Obtain nitrogenAre leaf structures and
What is the most obvious function of foliage leaves? What are some other functions that are often taken for granted?
Box 6-1 “Plants and People: Leaves, Food, and Death,” describes several ways that leaves affect animals. What is the name of the toxic chemical in leaves of poison hemlock and death camas? In
Most leaves can be quite thin. Why? What would be the condition of lower layers in a thick leaf?
What is the stalk of a leaf called? What is the broad, flat, thin part?
In many monocots such as grasses and irises, foliage leaves have a shape quite different from that of eudicot leaves. Their shape tends to be (circle two: long, short, tapering, wide). They lack a
Does a plant produce only one type of leaf during its entire life or can some plants produce various types of leaf (Figure 6-11)? Explain.Figure 6-11 (A) (B)
If a leaf has a blade that consists of one piece of tissue, we say the leaf is __________________. If the blade consists of several pieces, however, we say it is a __________________ leaf. What type
How can you distinguish between a compound leaf and a twig with several simple leaves? Assuming both a simple and a compound leaf have the same texture, which is more easily eaten by an insect larva?

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