Biology 2601A/B Midterm: Midterm 2 Review

164 views44 pages

orchidshark702

12 Dec 2017

School

Department

Course

Professor

For unlimited access to Study Guides, a Grade+ subscription is required.

Document Summary

For all of these processes, gases and water enter and exit the leaf. Stomata: holes on the bottom of the leaf. Inside the leaf all the cells are saturated with water: high water vapour, 100% humidity, outside of the leaf the air is dryer, this creates a driving force for water to diffuse out of the leaf. So when stomata open, water is lost: for every 1 molecule of carbon, 400 molecules of water are lost by the plant. Increase area available for diffusion to occur across: ex. More stomata, wider stomata: change concentration gradient. Less dry air = less water loss: ex. How do gases get in and out of leaves: through stomata. Stomata: pores in the leaf surface that allow access from the outside to air spaces inside the leaf: more than 90% of all gas exchange in the plant occurs through these pores.

Related Questions

Question 1

The key innovation that allowed for plant survival on land, seenin the first land plants and all others after, but not in thecharophytes, is

Question 1 options:

	fruit.
	vascular tissue.
	the seed.
	protection of the embryo.

Question 2

Which dramatic change in the alternation-of-generations lifecycle led to the protection of all phases of the life cycle and theformation of seeds?

Question 2 options:

	transition from a dominant gametophyte generation to a dominantsporophyte generation
	transition from a dominant sporophyte generation to a dominantgametophyte generation

Question 3

Which structure(s) allow the sporophyte of vascular plants to beprotected against drying out?

Question 3 options:

	the waxy covering of leaves, called the cuticle
	small openings in the leaves, called stomata
	guard cells that surround each stoma
	all of these structures protect the dominant sporophyte fromdrying out

Question 4

Why are the bryophytes called nonvascular plants?

Question 4 options:

	because they are specialized for transporting water and organicnutrients
	because their roots, stems, and leaves lack vascular tissue
	because they protect their embryo
	because they produce wind-blown spores

Question 5

Which generation is dominant in the bryophytes?

Question 5 options:

	the generations are equally dominant
	the sporophyte
	the gametophyte
	there is no sporophyte generation in bryophytes

Question 6

Which of the bryophytes are typically low-lying, due mostly totheir need for moisture and lack of vascular tissue?

Question 6 options:

	the mosses
	the liverworts
	the hornworts
	all of the bryophytes are low-lying

Question 7

Which structure of the moss protects the embryo from dryingout?

Question 7 options:

	the archegonium
	the antheridium
	the sporangium
	the stalk

Question 8

Cooksonia were the first __________ plants; they hadwind-blown spores, __________, leaves, and roots.

Question 8 options:

	nonvascular; branches
	vascular; seeds
	nonvascular; seeds
	vascular; branches

Question 9

The roots of today's lycophytes are much like __________ were inearly vascular plants; the vascular tissue is __________.

Question 9 options:

	roots; centrally placed
	stems; centrally placed
	leaves; only found at the perimeter
	branches; only found at the perimeter

Question 10

Pteridophytes, or ferns and their allies, are __________vascular plants with __________.

Question 10 options:

	seed-producing; microphylls
	seedless; microphylls
	seedless; megaphylls
	seed-producing; megaphylls

Question 11

Microphylls __________. Megaphylls__________.

Question 11 options:

	are found in all vascular plants; are only found in thelycophytes
	are broad leaves with a single strand of vascular tissue; arenarrow and have several strands vascular tissue
	are broad leaves with several strands of vascular tissue; arenarrow and have a single strand of vascular tissue
	are narrow and have a single strand of vascular tissue; arebroad leaves with several strands of vascular tissue

Question 12

The fern life cycle

Question 12 options:

	all of these choices accurately describe the fern lifecycle.
	is dependent on external water.
	relies on the wind to disperse the spores.
	produces a gametophyte that lacks vascular tissue.

Question 13

Seed plants use meiosis to produce

Question 13 options:

	spores and pollen.
	seeds and fruit.
	pollen and seeds.
	microspores and megaspores.

Question 14

In seed plants, a microspore develops into

Question 14 options:

	an egg.
	a pollen grain.
	a sporophyte.
	All of these answers correctly complete this sentence.

Question 15

Within the angiosperms, or ___________, two groups exist. Theyare named for their __________.

Question 15 options:

	vascular plants; number of cotyledons, or seed coats
	nonvascular plants; leaf type
	flowering plants; number of cotyledons, or seed coats
	fungi; leaf type

Question 16

The __________ parts of a flower are the stamens, each of whichhas two parts: the anther and the filament. The __________ parts ofa flower are the carpel, which has three major regions: the stigma,the style, and the __________.

Question 16 options:

	female; male; ovary
	male; female; sepals
	female; male; sepals
	male; female; ovary

Question 17

Double fertilization during the angiosperm life cycle involvestwo sperm, one of which __________, while the other __________.

Question 17 options:

	fertilizes the egg to form a zygote; produces the endospermnucleus, which will develop into food for the developing plant
	is a mature male gametophyte; is an immature malegametophyte
	lands on the carpel of the plant; is usually blown away in thewind
	develops into the seed; develops into the fruit that surroundsthe seeds

Question 18

The bodies of most fungi are made up of a network of filamentscalled hyphae.

Question 18 options:

	True
	False

Question 19

What is the difference between land fungi and the chytrids?

Question 19 options:

	Land fungi are motile and have flagella at all stages of theirlife cycle. The chytrids do not have flagella.
	Land fungi are nonmotile and do not have flagella at any stageof their life cycle. The chytrids have flagellated spores andgametes.
	Land fungi are nonmotile and only have flagellated spores. Thechytrids have flagellated spores and gametes.
	Both are motile for part of their life cycle. Land fungi aremotile as gametes. Chytrids are motile as spores.

Question 20

The vast majority of described species of fungi are __________fungi, which include unicellular __________, which reproducesexually once their food supply runs out. When yeast ferment, theyproduce ethanol and carbon dioxide.

Question 20 options:

	zygospore; black bread molds
	club; mushroom
	sac; yeast
	mutualistic; lichen

yellowmuskrat453

Background

Almost all animal and plant cells require oxygen and give off carbon dioxide. This is called gas exchange and it occurs by passive diffusion. Some animals do all or most of their gas exchange across their skin (for example amphibians) but they have very low metabolisms and use very little oxygen and get rid of very little carbon dioxide.

On the other hand humans (and other mammals) have very high metabolic requirements and we canât rely on gas exchange over the limited 1.5 to 2.0 square meters of our skin to get enough oxygen in and carbon dioxide out fast enough. Our gas exchange takes place across a very thin membrane in the Alveoli of the lung and the gas exchange surface in humans is estimated to be between 50 and 100 square meters, or between 25 and 67 times our skin surface area.

Our lungs provide a huge surface for gas exchange but they are a dead-end system. Once the oxygen in the lungs is used up it needs to be replenished and carbon dioxide builds up in the air spaces in the lungs and needs to get out. This is where the diaphragm and a few of the skeletal muscles become important. In its relaxed state the diaphragm is at its longest and the space in the thoracic cavity (and the lungs) is small. When the diaphragm contracts it shortens, which increases the volume of the thoracic cavity (and the lungs). The increase in size means the pressure is lower in the lungs than outside so air comes into the lungs (inhalation). As the diaphragm relaxes, the lungs decrease in size enough that the pressure inside the lungs is higher than the external air pressure so air comes out (exhalation).

Introduction

In this lab you will be building a model of a lung and experimenting with different ways to breath.

Supplies:

In the Lab Kit

One round 9" balloon (one lung, we donât need two for this)
medium-sized plastic bag large enough to fit over bottom end of bottle (diaphragm)
medium-size, thin rubber band

You supply

plastic 2-liter soda bottle with bottom cut off (thoracic cavity)

Tape (optional)

Directions:

1. Insert the balloon through the open bottom of a modified 2-liter soda bottle and up over the neck of the bottle. Pull the end of the balloon over the edges of the neck of the bottle. The balloon is held open by the neck of the bottle.

2. Place the plastic bag over the bottom (open) end of the 2-liter bottle and use the rubber band to hold it in place. This will serve as the diaphragm. To inflate the lung, blow into the balloon just before you fasten the rubber band. You can also wrap tape over the edges of the plastic bag to minimize air leaks

3. Grasp the bottom of the plastic bag and pull it down and push it up. Watch as the "lungs" (the balloon) expand and contract as you do this. The balloon has to change size because the air space between the balloon and bottle must remain constant. (Well, it would if the seal around the plastic bag and bottle were perfect).

You may block the "trachea" (the neck of the bottle) so that the air supply is cut off and watch as nothing happens when the "diaphragm" is pushed in and out.

This model isnât perfect. None of the joints are air tight as they would be in a real thoracic cavity. Pull the âdiaphragm down and watch the lungs expand . If you hold it in place, the lungs will collapse again over time. This is because of leaks and is not how real lungs work. Pushing the diaphragm in and pulling it out over and over does give you an idea of how lungs work. As the diaphragm tightens, contracts (pull down on the plastic bag) the lungs fill with air. As the diaphragm relaxes (push up on the plastic bag) air is expelled from the lungs .

There are several different ways we breath, i.e. expand our thoracic cavity so that our lungs can expand. You have just made a demonstration model of the diaphragm at work. You can also use your rib cage to expand and contract so that you can inhale and exhale. There are muscles between and around your ribcage which you can use to change the size of your thoracic cavity.

This is approximately what your model of a lung will look like.

Answer the questions on the Report Page

Report Page Name

1. Put a hand on your lower ribcage and try moving your ribs out and in. Does air also move in and out?

2. Someone with an upper back or neck injury may not have the options of using diaphragm or ribs to breath. They can learn to use the clavicle and the muscles attached to expand their thoracic cavity a small amount and breathe independently for short periods of time. Put your hand on you clavicle and try to raise and lower just that bone without using your diaphragm or your ribs. It isnât easy but you should be able to get a little air into and out of your lungs this way. How effective do you think this way of breathing is?

3. When you take a really deep breath you use all these muscle groups to help. Take a really deep breath and notice that your ribs expand, your lower abdomen comes out (a sign that the diaphragm has contracted) and your shoulders lift a little (the upper chest and clavicle are working). Now take a relaxed breath. Only your abdomen should go in and out. The movement of your abdomen is a result of the contracting diaphragm pushing on the contents of your âgutâ which forces your abdomen to push out.

Do you breath in or out when your diaphragm contracts?\

4. If a hole were poked in your thoracic wall (the wall of the pop bottle â the hole should be at least the diameter of a pencil)

a. what would happen when you tried to breath? (This is a pneumothorax).

b. Is the space between the balloon and plastic bottle still required to remain constant?

5. Would it be possible to live with a paralyzed diaphragm? Explain your answer.

fuchsiamuskrat152

Biology 2601A/B Midterm: Midterm 2 Review

Document Summary

Get access

Related Documents

Biology 2601A/B Lecture Notes - Lecture 10: Guard Cell, Epidermis, Stoma

Biology 2601A/B Lecture Notes - Lecture 22: Guard Cell, C3 Carbon Fixation, Stoma

Biology 2601A/B Lecture 11: 2601 Lec 11: Gas Exchange 2 - plants

Related Questions