Plants - BIOLOGY JUNCTION

8 Most Useful Bill Nye Videos To Watch

-Even if you are in college.

Bill Nye the Science Guy hasn’t produced new episodes since the end of Season 5 in 1998, but the show’s namesake host remains active in the promotion of science – and many of his videos remain outstanding content to watch even if you’re in College (or beyond).

Here at Biology Junction, our focus is on our own namesake subject, and that’s what this list focuses on – but for those of you who came here for a more general list, we’ve also included a few non-Biology videos down at the bottom. These videos are helpful regardless of what type of science you’re interested in, so everyone should take a look at them.

How We Chose These Videos

What good is a list without an explanation of how we made it? It wouldn’t be good science if we just threw it up here! Truth is, though, creating this list wasn’t very hard. First, we narrowed our list of sources to the best selections of Bill Nye videos – his classic show and the more-recent Greatest Discoveries series.

Next, we considered how useful each topic is to know. For students studying biology, it does no good to dive into topics more advanced than you’re ready for. Fortunately, most of Bill Nye’s videos are accessible even to beginners and provide a strong foundation for the topic. This ended up being a minor concern, but we were determined to go through the process.

Finally, we checked for the availability of videos. It doesn’t help to be told to watch a video if you can’t find it. A simple search should be enough to locate any of the videos on this list. If that fails, you should be able to get them from your library or preferred streaming service. We had a preference for videos that are freely available since budgets can be tight in college, but that didn’t significantly impact this list.

For our non-Biology videos, we used a similar process. Instead of emphasizing Biology, though, we decided to focus on the foundations of science and the information that’s most useful for everyone to know.

The Best Biology Videos From Bill Nye

Here are our top choices for Biology videos.

1: Biodiversity (S1 E9)

Biodiversity is the 9th episode of Bill Nye the Science Guy, and while it’s not the first to feature a Biology topic, we think it’s easily one of the most important episodes. This video focuses on more than just where things live – it also explains the concept of ecosystems and how important it is to have a variety of living things in each area.

Arguably the most important lesson of this episode is understanding that ecosystems are far more complex than figuring out which living things eat each other. Each part of an ecosystem affects all of the other parts. That’s why we have to be so careful when introducing plants or animals to new habitats – if the ecosystem isn’t ready to handle it, the whole thing could collapse.

A second lesson to focus on is how ecosystems can vary in size – and, in many cases, overlap each other. The Great Barrier Reef has its own ecosystem, but it’s part of the larger Pacific Ocean – and from there, it ultimately affects all life on the planet (even if the impact isn’t obvious).

Understanding biodiversity is critical to understanding biology as a whole. Life does not exist in a vacuum – not unless we put it there, anyway. Environments affect life and vice versa, and if you want to understand why something is the way it is, you have to look at the bigger picture.

2: Cells (S1 E17)

Cells are a fundamental component of life – and even if you think you understand them, it’s good to get a refresher on the topic before you start your studies. The main reason for this is that when we say something “affects an organ”, what we mean is “it affects certain cells of the organ in a particular way”.

For example, if you want to understand why too much alcohol can hurt the liver, you need to look at its impact on the cells of the liver. If you want to heal that liver when you’re done, you have to figure out what will encourage the cells to do that. Cells are the ultimate “micro” topic in biology, making the Bill Nye cells video easily one of the most important episodes for biologists to watch.

3: Food Web (S2 E6)

It’s hard to talk about biology without eventually talking about food – but how things get their food is a little more complicated. Only watch this video after you’ve watched Biodiversity, because that video provides some important groundwork for this topic.

The short version is that a food web describes how each part of an ecosystem gets its food. Ultimately, each living thing gets food either from other living things (like insects, plants, or rodents) or from the sun. Every living creature is ultimately dependent on plants – who, let’s not forget, are often nourished by the uneaten bodies of dead creatures.

(If you’re having flashbacks to a certain Disney movie about a young lion, there’s a reason for that – the Circle of Life, where living things depend on each other, is quite real.) Watch Food Web

4: Plants (S3 E3)

Given how important plants are to the previous video, now’s a good time to get a refresher on what they are, how they work, and what sort of impact they have on our lives. The crazy thing is how plants can synthesize their own food as long as they have sunlight, water, and carbon dioxide – though healthy soil and a few other nutrients certainly help.

Plants are also important for their impact on other aspects of Biology. For example, many medicines are made from plants or plant by-products and affect certain living things in specific ways. Once we understand how something works, we can start figuring out the best way to make use of it.

This is particularly helpful if you’re looking for a job with biology. Most of your work will likely involve seeing how various inputs (types of food, situations, etc.) affect living things, and plants will be a part of that. Studying life alone is a limited topic – but there are endless possibilities when studying the way things affect life.

5: Populations (S3 E19)

Populations are a group of similar living things living in a set area. We often refer to the population of the human race, but we may also talk about the population of a specific city, voting district, or another region.

In biology, the most important thing is understanding the populations of other living things, how they’ve changed over time, and what’s caused them to do so. As you learned in videos like Biodiversity and Food Web, living things all affect each other – and a sudden rise or drop in one population will ripple across the ecosystem and begin affecting other creatures.

There may not be as many fancy names or scientific terms here, but it’s still worth watching this video to ensure you have a good grasp of the fundamentals of biology.

6: Biology – Greatest Discoveries

Finally, Bill Nye’s Greatest Discoveries video on Biology rounds out the best videos on this topic with a look at 13 of the most important discoveries in biology. This includes a discussion on the discovery and impact of:

Microorganisms like bacteria, blood cells, and sperm
The Cell Nucleus that functions at the center point of most cells
Archaea, microorganisms that lack a cell nucleus but aren’t quite like bacteria
Cell Division, the process of growth and, in many ways, life itself
Sex Cells and how they differ from most other types of cells
Cell Differentiation and how different types of cells are made
Mitochondria, which are separate from cells but provide a critical function for metabolizing chemicals
The Krebs Cycle, which is how protein, fats, and sugars are turned into energy
Neurotransmission, which centralizes the body’s ability to control itself
Hormones, which are far more complicated than teenage urges
Photosynthesis, a process where light is turned into chemical energy
Ecosystems, a quick look back at larger ecological units
Tropical Biodiversity, or why warm and sunny places tend to have a much greater variety of life

Together, all of these are important for biologists to know.

The Best Overall Science Videos From Bill Nye

Whether or not you’re focused on biology, these videos are helpful for improving your overall understanding of science and are worth watching at any age.

1: Pseudoscience (S4 E9)

Many things that sound like science but aren’t. These things are often called pseudoscience, and learning how to recognize them is a valuable skill for any scientist. Fortunately, the entire topic can be brought down to a few simple principles.

First, science involves testing claims and ideas. If somebody says something can’t be tested, then it’s not within the realm of science and shouldn’t be treated as such. In those cases, it’s okay to say “perhaps we’ll never know for sure”.

Second, extraordinary claims require extraordinary proof. In other words, the more important your claim is, the more you need to support it with verifiable evidence. As the person making a claim, it is your job to provide corresponding proof. It is not the job of others to demonstrate that you’re right.

Furthermore, your results should be reproducible. Proper science only happens when someone tries to prove you wrong – fairly, of course – and fails to do so. If you repeat an experiment and keep getting results, you don’t have any answers – just more questions to ask.

Finally, you should learn critical thinking. This graphic is especially helpful for that and provides many questions that help you uncover the truth. For example, when presented with a claim, you may want to figure out who benefits from it, what the best/worst case scenarios of it are, where it might be a problem or solution, what might make it unacceptable, why people might need it, and how to approach it safely.

In many cases, purveyors of pseudoscience are simply looking to profit from your ignorance. As a scientist, it is your duty to see past things like that and uncover the truth. Watch Pseudoscience now.

2: Measurement (S5 E17)

Coming in as one of the last episodes ever aired, Measurement is something that honestly should have been one of the first videos they made. Measuring things is critical to the foundations of science as a whole. Proper measurements provide objective, verifiable information using a common set of standards, and it’s impossible to overstate how important this is.

There are a few important things to learn from this video, Measurement.

First, there are many ways of measuring things. You can measure units (members of a population), dimensions (the size of something), time (how long it takes something to happen), effects (what happens), and many other topics.

Second, you’ll learn why things should be measured. It’s not just to expand the amount of information we have, though that’s valuable in and of itself. Instead, measurements help us understand what’s different about two subjects so we can proceed to uncover why and how that difference occurred.

Taken far enough, this can lead to discoveries, such as finding that one person in a neighborhood didn’t get sick because they ate a particular herb.

Measurements are almost never a focus in and of themselves – but they’re a vital part of most scientific activities. If you want to be a scientist, then you’re almost certainly going to do a lot of measurements over the course of your career. That makes this innocent-sounding video one of the most helpful episodes of Bill Nye.

Everything You Need to Know About the Calvin Cycle

The Calvin Cycle occurs during photosynthesis and consists of light independent redox reactions that convert carbon dioxide into glucose. This conversion happens in the chloroplast, or more specifically the stroma of the chloroplast. The chloroplast region is an area between the thylakoid membrane and the inner membrane of the organelle which is typically located in the leaves of plants.

This cycle used to create carbon sugars, mostly, was discovered by Melvin Calvin, Andrew Benson, and James Bassham in 1950 at the University of California. The used radioactive material to trace the pathways carbon atoms took during the carbon fixation step in plant life.

You’ve probably heard the Calvin Cycle called a few other names including the CBB Cycle, C3 Cycle, and dark reactions to name a few.

This process of carbon fixing by plants is essential to all life on the planet. Most new organic growth stems from plants converting carbon to sugars either directly or indirectly. Other plants, or animals, can use these sugars to forms more complex sugars and amino acids when they consume them. It all stems from little plants working day and night to capture light and water.

A Technical Take on the Calvin Cycle

The Calvin Cycle occurs during photosynthesis and is repeated until it forms a glucose molecule. Photosynthesis goes through two stages to create food and building materials for plants to grow. During the first stage, chemical reactions from light produce ATP and NADPH. The second stage is when the Calvin Cycle takes place. In this stage, carbon dioxide and water get converted to organic materials like glucose. These reactions are called dark reactions which confuses people, but they do not take place at night.

The short explanation of the Calvin Cycle is that it begins with carbon fixation. Carbon dioxide molecules are plucked out of the air to produce glyceraldehyde 3-phosphate. RuBisCO, an enzyme found abundantly around the planet, brings on the carboxylation of a 5-carbon compound and provides a 6-carbon compound that halves itself form two 3-phosphoglycerate. The enzyme phosphoglycerate kinase uses the phosphorylation to create biphosphoglycerate.

Next, the enzyme glyceraldehyde 3-phosphate dehydrogenase uses the reduction of biphosphoglycerate by NADPH. This is called the reduction reactions. Eventually, when the cycle ends, the reactions and reductions produce one glyceraldehyde 3-phosphate molecule per every three carbon dioxide molecules.

That’s a lot of massive words. What that means is the plant uses light and water to convert carbon dioxide into nutrients and oxygen. It takes six turns on the Calvin Cycle for the plant to produce a single glucose molecule. Now that we simplified the process, let’s look at the chemical equation for the Calvin Cycle:

3 CO2 + 6 NADPH + 5 H2O + 9 ATP → glyceraldehyde-3-phosphate (G3P) + 2 H+ + 6 NADP+ + 9 ADP + 8 Pi (Pi = inorganic phosphate)

The Simplified Function of the Calvin Cycle

How plants create sugar from sunlight, water, and carbon dioxide is complicated as you probably noted from the previous section. However, plants toil away day and night creating glucose, starch, and cellulose so they can grow. The Calvin Cycle plucks carbon molecules right out of the air and creates new plant growth.

The Calvin Cycle is vital to every ecosystem, and it reaches far beyond the plants using it. Plants are the building blocks of all the food in any ecosystem. Herbivores eat plants for energy and growth while carnivores eat herbivores for the same reasons. In the end, everything goes back into the ground and plants start the process all over again.

If plants stopped all their hard work tomorrow, it would only take a few days for animals to start feeling the effects and starving. Herbivores lose their food right away. Carnivores would follow behind the herbivores. Plants make most of the basic building blocks we all need to continue life as we know it. Without their hard work, we’d all be doomed.

While plants are supplying us with the building blocks, we need to continue living, and they help out the environment in other ways. Because the Calvin Cycle depends on carbon dioxide, plants indirectly play a role in regulating carbon dioxide and other gases proven to be harmful to the atmosphere. Plants perform an essential role in helping us clean the air we breathe.

The Calvin Cycle Step by Step

Carbon fixation is the first step. We explained it in brutal technical detail above, but let’s look at it in simpler terms in this section. A carbon dioxide molecule is plucked from the air and combined with a five-carbon acceptor molecule called ribulose-1,5-bisphosphate, or RuBP for short. The result is a six-carbon molecule.

The six-carbon molecule is split in half to form a set of new carbon molecules called 3-phosphoglyceric acid, or 3-PGA for short. The new three-carbon molecules are catalyzed by an enzyme called RuBisCo. This creates the simple sugar molecules the Calvin Cycle needs for stage two. On a side note, because it is used by every plant during photosynthesis, the RuBisCo enzyme if the most common catalyst on Earth. The result of this step is passed on to the next phase.

Step two of the Calvin Cycle is called the reduction step. The 3-PGA molecules created in the carbon fixation step are used in phase two to develop glyceraldehyde-3 phosphate or G3P for short. G3P is a simple sugar. This process uses energy and reactions captured during light-dependent stages of photosynthesis.

This step is called the reduction step because electrons are stolen from molecules created during photosynthesis and given to our new sugars. In chemistry, when you take electrons from a molecule, it’s called a reduction hence the name of this stage. Technically, the electrons are donated and not taken. Taking electrons by force is called oxidation, and that’s not what happens in this stage.

At this point, our plant has created sugar it can store for a long time and use for energy. Anything that eats this plant gets to take advantage of these sugars as well including humans. The plant may choose to use these stored molecules to form new plant materials or repair itself, but that’s not part of the Calvin Cycle so we won’t get into it. This is the end of the sugar-producing phase of the Calvin Cycle.

The final stage of the Calvin Cycle is called the regeneration step. Some of the G3P are held back and not used to make sugars. Instead, they are used to revitalize the five – carbon compound the Calvin Cycle needs to start the process over again. It takes six carbon molecules to make glucose, so plants have to go through the Calvin Cycle six times to make one glucose molecule.

Once the plant has completed this cycle six times, the Calvin Cycle ends and begins again. So, technically, the Calvin Cycle is all three steps done six times each. Plants repeat this process over and over during daylight hours. At night they continue to work making various compounds that don’t require light. This makes plants the most efficient lifeforms on the planet.

Bonus Information About Plants and Their Internal Food Factories

We usually consider waste products bad or at least not edible. However, we need the waste materials plants to produce to survive. An essential waste, or by-product, plants produce is oxygen. While plants are using water and carbon dioxide to make sugars, they release oxygen into the air around them as a waste product.

The delicious fruits and vegetables we all enjoy get most of their flavor from the carbon sugars plants store for energy. From the crunchy stalk of the celery plant to the succulent meat of the peach, plants developed all using just carbon dioxide, water, sunlight, and a few minerals leeched from the soil. I think we can assume these tasty treats are little gifts from the plant kingdom.

The tiny organelles called chloroplasts on the surface of a plant’s leaves can move. Ok, they can’t move individually, but in many plants, they can turn the leaf, so it gets better exposure to sunlight. These plant-based solar cells help capture sunlight so being able to point yourself in the sun makes sense. Some plants take it to another level and bend their stalk or branches to help reach the sunlight.

Some Final Notes

The fantastic plants we ignore all around us are vital to our survival. They use energy from the Sun in little energy reactors called chloroplasts to do all sorts of cool things. If you glance at the bigger picture and oversimplify it, plants take light from the Sun and turn it into carbon sugars they can store for long periods of time. We could call them solar powered batteries if we want to be humorous about the process.

Plants pitch in and help everywhere they can from cleaning the air to enriching the soil they grow in for the next plants. Plants give us so many things from apples to steak. Without plants toiling away at the bottom of the food chain, nothing in the top of the food chain could survive. Every food we consume comes from plants either directly or indirectly.

Seed Plants

%CODE1%

Name:

Seed Plants

True/False

Indicate whether the sentence or statement is true or false.

Tracheids and sieve tubes make up a xylem vessel.

The main function of ground tissue is to conduct water and minerals.

Vascular tissue is found within ground tissue, which makes up the outside of the plant.

The outer protective layer of tissue on a vascular plant is known as the meristem.

Monocot stems cannot become large in diameter because they lack lateral meristems.

The loss of water by transpiration at the leaves helps pull water into the plant at the roots.

The blade of a compound leaf is divided into leaflets.

Many gymnosperms, such as pine, spruce, and fir trees, produce their seeds in cones.

The flowers of angiosperms are ornamental and have no reproductive function.

10.

Brightly colored petals, scents, and nectar are all adaptations of flowers that help ensure pollination.

11.

Plants with colorful flowers are pollinated most commonly by wind.

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

12.

The conducting cells of phloem are called

a.	tracheids.	c.	sieve plates.
b.	sieve tube members.	d.	vessel elements.

13.

Plants grow in regions of active cell division called

a.	meristems.	c.	phloem.
b.	xylem.	d.	dermal tissue.

14.

The lengthening of plant roots and shoots is called

a.	secondary growth.	c.	primary growth.
b.	germination.	d.	vascular growth.

15.

Refer to the illustration above. The structure indicated at “f”

a.	supports the anther.
b.	produces pollen.
c.	has tiny structures that look like leaves.
d.	develops into a fruit.

16.

Refer to the illustration above. The structure labeled “c”

a.	produces pollen.	c.	is sticky to the touch.
b.	contains sperm cells.	d.	contains meristematic tissue.

17.

The process of transferring pollen from a male cone to a female cone in gymnosperms is called

a.	fertilization.	c.	pollination.
b.	seed formation.	d.	asexual reproduction.

18.

If a plant’s flowers are very colorful and produce nectar, the plant is probably pollinated by

a.	water.	c.	insects.
b.	wind.	d.	self-pollination.

19.

Fertilization

a.	involves the union of the egg and sperm.
b.	may not follow pollination at all.
c.	may not occur until weeks or months after pollination has taken place.
d.	All of the above

20.

After an egg has been fertilized, a fruit develops from the

a.	style.	c.	ovule.
b.	ovary.	d.	sepal.

Moss & Fern Quiz

%CODE1%

Name:

Moss and Fern

True/False

Indicate whether the sentence or statement is true or false.

Land plants have a complex life cycle that involves an alternation of generations between a haploid gametophyte and a diploid sporophyte.

The sporophyte of a nonvascular plant is larger and lives longer than the gametophyte.

The life cycle of nonvascular plants involves alternation of generations.

Mosses, liverworts, and hornworts all are generally found in moist habitats.

Nonvascular plants have true leaves but lack true stems and roots.

Mosses and ferns no longer require the presence of a film of water for reproduction.

Ferns need water to reproduce because their sperm must swim to eggs.

Mosses are called pioneer plants because they can promote the development of new communities in barren areas that have been burned or destroyed by humans.

Sphagnum moss is used in potting and gardening soils because of its ability to encourage water drainage.

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

10.

The ancestors of today’s land plants were probably

a.	brown algae.	c.	green algae.
b.	red algae.	d.	lichens.

11.

The challenges faced by early land plants included

a.	conserving water.
b.	reproducing on land.
c.	absorbing minerals from the rocky surface.
d.	All of the above

12.

The diploid form in a plant’s life cycle is called the

a.	sporophyte.	c.	parental generation.
b.	gametophyte.	d.	alternate generation.

13.

The haploid form in a plant’s life cycle is called the

a.	sporophyte.	c.	parental generation.
b.	gametophyte.	d.	alternate generation.

14.

Which of the following is not a bryophyte?

a.	moss	c.	hornwort
b.	liverwort	d.	fern

15.

Which of the following is not characteristic of all nonvascular plants?

a.	They produce seeds.
b.	They have an alternation of generations lifestyle.
c.	They produce spores.
d.	They require water for sexual reproduction.

16.

The water-retaining ability of sphagnum moss makes it ideal for

a.	using in garden-soil mixes.
b.	use in packing bulbs and flowers for shipping.
c.	use in houseplant soils.
d.	All of the above

17.

Similarities shared by monocots and primitive dicots suggest that

a.	monocots and dicots evolved independently.
b.	monocots were on Earth long before dicots.
c.	monocots evolved from dicots.
d.	dicots evolved from monocots.

Introduction to Plants Study Guide

%CODE1%

Name:

Introduction to Plants Quiz

Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.

Plants are multicellular prokaryotes. _________________________

The plant life cycle includes a diploid gamete and a haploid spore. _________________________

Mosses are most often found in dry environments. _________________________

Mosses and liverworts lack a vascular system for transporting water and nutrients. _________________________

Water must be present for fertilization to take place in mosses. _________________________

In mosses and liverworts, eggs are formed through mitosis in the antheridia. _________________________

Gametophytes of conifers are physically much larger than their sporophytes. _________________________

One important difference between mosses and ferns is that mosses have a vascular system. _________________________

Shoots, stems, and roots characterize the bodies of vascular plant sporophytes. _________________________

10.

Ferns are characterized by fronds and fiddleheads. _________________________

11.

Haploid fern spores are produced by gametophytes. _________________________

12.

In ferns, a large sporophyte with leaves called fronds alternates with a heart-shaped gametophyte. _________________________

13.

Ferns need water to reproduce because their sperm must swim to eggs. _________________________

14.

Both mosses and ferns require a thin film of water for gametes to meet. _________________________

15.

In both mosses and ferns, eggs are formed through mitosis in the antheridia. _________________________

16.

Gymnosperm seeds are enclosed in a fruit. _________________________

17.

Gametophytes of seed plants are large and easily viewed with the unaided eye. _________________________

18.

Sexual reproduction in seed plants involves the transfer of pollen from the male reproductive structures of a plant to the female reproductive structures. _________________________

19.

Seed plants cannot reproduce without a film of water for transferring of gametes. _________________________

20.

A seed is a structure that contains a plant embryo. _________________________

21.

A plant embryo is a new sporophyte. _________________________

22.

In flowering plants, the embryos of monocots have two cotyledons. _________________________

23.

Pollen is produced in the tip of the stamen, a structure called the sepal. _________________________

24.

The lower portion of the pistil produces pollen. _________________________

25.

Gametophytes develop within flowers. _________________________

26.

Pollen tubes grow through the style toward the ovule. _________________________

27.

Many seeds have appendages that aid in dispersal. _________________________

28.

Asexual reproduction produces new plants that are genetically different from the parent plant. _________________________

29.

Vegetative reproduction does require a plant to have flowers. _________________________

30.

In vegetative reproduction, new plants may be generated from stems or roots. _________________________

Multiple Choice
Identify the choice that best completes the statement or answers the question.

31.

The ancestors of today’s land plants were probably

a.	brown algae.	c.	green algae.
b.	red algae.	d.	lichens.

32.

Among the challenges that faced early land plants were

a.	eliminating excess water.
b.	obtaining sunlight for photosynthesis.
c.	absorbing minerals from the rocky surface.
d.	avoiding being eaten by grazing mammals.

33.

The waxy protective covering of a land plant is called a

a.	cuticle.	c.	rhizome.
b.	capsule.	d.	stoma.

34.

Some land plants developed an internal system of interconnected tubes and vessels called

a.	cuticles.	c.	a circulatory system.
b.	nonvascular canals.	d.	vascular tissue.

35.

sporophytes : spores ::

a.	sporophytes : gametophytes	c.	gametes : gametophytes
b.	gametophytes : gametes	d.	sporophytes : gametes

36.

The diploid form in a plant’s life cycle is called the

a.	sporophyte.	c.	parental generation.
b.	gametophyte.	d.	alternate generation.

37.

The haploid form in a plant’s life cycle is called the

a.	sporophyte.	c.	parental generation.
b.	gametophyte.	d.	alternate generation.

38.

A haploid stage following a diploid stage in a plant’s life cycle is called

a.	generational recycling.	c.	alternating forms.
b.	periodic gametogenesis.	d.	alternation of generations.

39.

In plants, haploid gametes are produced as a result of

a.	fertilization.	c.	encapsulation.
b.	meiosis.	d.	mitosis.

40.

sporophytes : meiosis ::

a.	sporophytes : spores	c.	gametophytes : gametes
b.	gametophytes : mitosis	d.	sporophytes : gametes

41.

Mosses, hornworts, and liverworts all possess

a.	fibrous roots.	c.	tap roots.
b.	spore capsules.	d.	green leaves.

42.

In nonvascular plants, structures in which spores are produced are known as

a.	meristems.	c.	cones.
b.	pollen grains.	d.	sporangia.

43.

Which of the following statements about moss spores is not true?

a.	They are produced by the sporophyte.
b.	They are dispersed and then germinate.
c.	They are produced in a capsule-like top.
d.	They are diploid.

44.

The sporophyte generation in mosses produces spores by

a.	meiosis.	c.	sexual reproduction.
b.	mitosis.	d.	asexual reproduction.

45.

The most noticeable form of a moss life cycle is the

a.	sporophyte.	c.	rhizoid.
b.	gametophyte.	d.	zygote.

46.

In which of the following structures do seedless plants produce eggs?

a.	antheridia	c.	archegonia
b.	capsules	d.	cones

47.

antheridia : sperm ::

a.	rhizoids : gametes	c.	archegonia : eggs
b.	seeds : gametophytes	d.	sperm : megaspores

48.

Both mosses and ferns produce

a.	seeds.	c.	flowers.
b.	fruit.	d.	spores.

49.

Fern sporophytes consist of rhizomes,

a.	large leaves, and flowers.	c.	pollen grains, and ovules.
b.	cones, and stems.	d.	roots, and fronds.

50.

Unlike mosses, ferns possess

a.	spore capsules.	c.	antheridia.
b.	archegonia.	d.	vascular tissue.

51.

Fiddleheads are produced by

a.	whisk ferns.	c.	ferns.
b.	club mosses.	d.	horsetails.

52.

Both mosses and ferns produce gametes through

a.	mitosis.	c.	osmosis.
b.	meiosis.	d.	diffusion.

53.

vascular plants : sporophytes ::

a.	sporophytic plants : gametophytes	c.	spores : gametes
b.	gametes : sporophytes	d.	nonvascular plants : gametophytes

The diagram below shows the plant life cycle.

54.

Refer to the diagram above. At which point in the life cycle does fertilization take place?

a.	1	c.	3
b.	2	d.	4

55.

Refer to the diagram above. The structures produced at 3 are called

a.	sporangia.	c.	spores.
b.	archegonia.	d.	antheridia.

56.

Which of the following were the first land plants to evolve seeds?

a.	angiosperms	c.	mosses
b.	gymnosperms	d.	horsetails

57.

liverworts, hornworts, and mosses : nonvascular plants ::

a.	gymnosperms and angiosperms : bryophytes
b.	ferns : mosses
c.	gymnosperms and angiosperms : seed plants
d.	bryophytes and liverworts : vascular plants

58.

gymnosperms : naked seeds ::

a.	pollen : mosses	c.	liverwort : vascular tissue
b.	liverwort : pollen	d.	angiosperms : enclosed seeds

59.

In seed plants, female gametophytes produce

a.	sperm.	c.	cells.
b.	eggs.	d.	spores.

60.

A male gametophyte of a seed plant develops into a

a.	pollen grain.	c.	pollen tube.
b.	spore capsule.	d.	seed coat.

61.

The partially developed plant found in seeds is known as a(n)

a.	gametophyte.	c.	embryo.
b.	spore capsule.	d.	sporophyte.

62.

A typical seed contains all of the following except a(n)

a.	seed coat.	c.	embryo.
b.	nutritious tissue.	d.	spore case.

63.

The tallest trees in the world are a species of

a.	conifers.	c.	liverworts.
b.	dicots.	d.	angiosperms.

64.

The process of transferring pollen from a male cone to a female cone in gymnosperms is called

a.	fertilization.	c.	pollination.
b.	seed formation.	d.	asexual reproduction.

65.

In conifers, the diploid condition is resumed following

a.	pollination.	c.	respiration.
b.	fertilization.	d.	sporulation.

66.

The seeds of monocots have

a.	one embryo and two cotyledons.	c.	one embryo and one cotyledon.
b.	two embryos and two cotyledons.	d.	two embryos and one cotyledon.

67.

Flowering plants are classified as monocots or dicots according to the number of their

a.	leaves.	c.	meristems.
b.	flowers.	d.	cotyledons.

68.

Monocots and dicots are subdivisions of

a.	angiosperms.	c.	ferns.
b.	gymnosperms.	d.	mosses.

69.

Refer to the diagram above. The structure labeled f

a.	supports the anther.	c.	supports the pistil.
b.	produces pollen.	d.	develops into a fruit.

70.

Refer to the diagram above. The structure labeled c

a.	produces pollen.
b.	contains sperm cells.
c.	is the area where pollen lands and sticks.
d.	contains meristematic tissue.

71.

Removing a flower’s stigma would initially affect

a.	fertilization.	c.	pollination.
b.	seed production.	d.	seed dispersal.

72.

Pollen is produced in a structure called the

a.	anther.	c.	ovary.
b.	stigma.	d.	pistil.

73.

In angiosperms, immediately following pollination,

a.	the seed develops.	c.	fertilization occurs.
b.	an egg cell is formed.	d.	the pollen tube begins to form.

74.

During fertilization in flowering plants, one sperm fuses with an egg to form an embryo, and another fuses with two nuclei to form nutritive tissue. This event is called

a.	self-pollination.	c.	maximization.
b.	adaptation.	d.	double fertilization.

75.

fruit : mature ovary

a.	gametophyte : sporophyte	c.	cotyledon : food reserve
b.	gymnosperm : angiosperm	d.	vascular plant : nonvascular plant

76.

If a plant’s flowers are very colorful and produce nectar, the plant is probably pollinated by

a.	water.	c.	insects.
b.	wind.	d.	self-pollination.

77.

One way that flowers produced by angiosperms help ensure the transfer of gametes is by

a.	traveling in the air currents.
b.	bursting open and projecting gametes onto the landscape.
c.	attracting animals that carry pollen from one flower to another.
d.	producing tasty fruits that animals depend on for food.

78.

What function do all fruits produced by angiosperms perform?

a.	produce nutrients for the plant
b.	nourish the embryos
c.	disperse the seeds
d.	ensure pollination

79.

Which structure allows plants to reproduce asexually?

a.	tuber	c.	archegonium
b.	flower	d.	antheridium

80.

The production of offspring genetically identical to the parent plant is the result of

a.	sexual reproduction.	c.	alternation of generations.
b.	asexual reproduction.	d.	double fertilization.

Completion
Complete each statement.

81.

The surface of a vascular plant is covered by a waxy, waterproof layer called a(n) ____________________.

82.

One of the first environmental challenges that early land plants had to overcome was developing a way to conserve ____________________.

83.

The sporophyte generation produces spores by the process of ____________________.

84.

The haploid form of a plant is known as the ____________________ generation.

85.

Nonvascular plants transport materials within their bodies through the process of ____________________.

86.

A green, hornlike sporophyte growing upward from the gametophyte is typical of plants known as ____________________.

87.

In mosses and liverworts, the ____________________ generation is the dominant generation.

88.

The very tiny liverwort ____________________ grow from the archegonia under the caps of female stalks.

89.

The gametophytes of ____________________ plants are larger and more noticeable than the sporophytes.

90.

The seedless plants produce sperm within the ____________________.

91.

True roots, stems, and leaves are associated with ____________________ plants.

92.

A fern is an example of a(n) ____________________ vascular plant.

93.

Both mosses and ferns produce eggs within structures called ____________________.

94.

Like the nonvascular plants, the seedless vascular plants can reproduce sexually only when a film of ____________________ covers the gametophyte.

95.

Unlike mosses, ferns have sporophytes that are much ____________________ than their gametophytes.

96.

Seed plants whose seeds do not develop within a sealed container (fruit) are called ____________________.

97.

Fruit is a characteristic associated only with the flowering plants, or ____________________.

98.

A male gametophyte of a seed plant develops into a(n) ____________________.

99.

The ____________________ is the protective cover that surrounds a seed.

100.

The seed coat prevents the embryo from drying out, from mechanical injury, and from ____________________.

101.

A(n) ____________________ is a specialized structure that develops from an ovule and serves to protect a plant embryo from harsh conditions.

102.

The four major groups of gymnosperms are gnetophytes, cycads, ginkgoes, and ____________________.

103.

A mature pine tree produces both male and female ____________________.

104.

Gymnosperms are pollinated by ____________________, which makes sexual reproduction possible even during dry conditions.

105.

The life cycle of a conifer is characterized by a large ____________________ generation.

106.

In conifers, seeds form on the ____________________ of cones.

107.

A plant that has flower parts that occur in fours or fives or multiples of four or five is a member of a subgroup called a(n) ____________________.

108.

Refer to the diagram above. The structure labeled f is called the ____________________.

109.

Refer to the diagram above. The structure labeled b is called the ____________________.

110.

Refer to the diagram above. A flower like this one has all four basic flower parts and thus is an example of a(n) ____________________ flower.

111.

The transfer of pollen grains from an anther to a stigma is known as ____________________.

112.

In angiosperms, seeds develop from the ____________________ inside a(n) ____________________ after an egg has been fertilized.

113.

The event in which one sperm fertilizes an egg and a second sperm fuses with two nuclei is called _________________________.

114.

A flower is a(n) ____________________ structure that produces pollen and seeds.

115.

Flowers are a source of ____________________ for pollinators.

116.

The seeds of angiosperms are enclosed in ____________________.

117.

Because flowering plants are rooted in the ground and cannot move from place to place, they must disperse their ____________________ so that their offspring can grow in new environments.

118.

Many fruits are spread by ____________________ that are attracted to sweet, fleshy fruits, which they use for food.

119.

Many of the structures by which plants reproduce vegetatively are modified ____________________.

120.

Bulbs, stolons, and tubers are examples of modified stems that allow plants to reproduce ____________________.