Module 15

Question 1

Physiology

Answer 1

The study of life processes in an organism.

Question 2

Nastic movement

Answer 2

a plants response to a stimulus such that the direction of the response is pre-programmed and not dependent of the direction of the stimulus.

Question 3

Pore spaces

Answer 3

spaces in the soil that determine how much water and air the soil can hold.

Question 4

Loam

Answer 4

a mixture of sand silt, gravel clay and other organic matter.

Question 5

Cohesion

Answer 5

the phenomenon that occurs when molecules are so strongly attracted to each other that they tend to stay together, even when exposed to tension.

Question 6

Translocation

Answer 6

the process by which organic substances move through the phloem of a plant.

Question 7

Hormones

Answer 7

Chemicals that circulate throughout multicellular organisms, regulating cellular processes by interacting with specifically targeted cells.

Question 8

Phototropism

Answer 8

a growth response to light.

Question 9

Gravitropism

Answer 9

a growth response to gravity.

Question 10

Thigmotropism

Answer 10

a growth response to touch

Question 11

Perfect flowers

Answer 11

flowers with both stamens and carpels

Question 12

Imperfect flowers

Answer 12

flower that have either stamens or carpels, not both.

Question 13

Pollination

Answer 13

the transfer of pollen grains from the anther to the carpel in flowering plants.

Question 14

Double fertilization

Answer 14

a fertilization process that requires two sperm to fuse with two other cells.

Question 15

Seed

Answer 15

an ovule with a protective coating, encasing a mature plant embryo and a nutrient source.

Question 16

Fruit

Answer 16

a mature ovary that contains a seed or seeds.

Question 17

Name the four processes for which plants require water. Which of these processes can be neglected
for a short amount of time?

Answer 17

a plant uses water for photosynthesis, turgor pressure, hydrolysis, and transport. since a plant can wilt without dying, turgor pressure can be ignored for a short time.

Question 18

A biologist studies two plants. The flowers of the first plant open each morning and close each
night. The second plant’s flowers stay open all of the time. However, if the plant is placed so that one
of its sides is in the shade and the other is in the sunlight, the plant will eventually grow so that all of
its leaves point towards the sunlight. Which plant is using nastic movement and which is using
phototropism?

Answer 18

.the first plant is using nastic movements and the second is using phototropism.

Question 19

Briefly describe the cohesion-tension theory of water transport in plants.

Answer 19

the cohesion-tension theory states that when water evaporates through the stomata in a plants leaves, a deficit of water is created. this causes the water molecules just below those that evaporated to move up and take their place. since water molecules like to stay together, however, the water molecules just below the ones that moved up also move up, in order to stay close. this causes a chain reaction, eventually causing water from the roots to move up into other parts of the plant.

Question 20

Do xylem cells need to be alive in order for xylem to do their job? Why or why not?

Answer 20

xylem cells need not be alive for xylem to do their job, the xylem cells need not play an active role in the transport.

Question 21

Do phloem cells need to be alive in order for phloem to do their job? Why or why not?

Answer 21

Phloem cells must be alive in order for the the phloem to do their job , because phloem cells take an active part in translocation.

Question 22

What substances do xylem contain? What substances do phloem contain?

Answer 22

xylem contain water and dissolved minerals, while phloem contain sugar and organic substances.

Question 23

Do insectivorous plants really eat insects? Why or why not?

Answer 23

insectivorous plants do not really eat insects. they decompose the insects and use their raw materials for biosynthesis.

Question 24

From a genetic point of view, what is the difference between vegetative reproduction and sexual
reproduction in plants?

Answer 24

.vegetative reproduction leads to offspring with genetic codes which are identical to the parent . sexual reproduction leads to offspring with genetic codes which are similar to, but not identical to, the parents genetic codes.

Question 25

A gardener says that one limb of his crabapple tree now produces normal-sized apples. What must the gardener have done to make this happen?

Answer 25

The gardener must have grafted limbs from a tree that produces normal-sized apples to his crabapple tree.

Question 26

What is the male reproductive organ of a flower? What is the female reproductive organ?

Answer 26

.the stamen is the male reproductive organ, and the carpel is the female.

Question 27

Why are the pollen grains and embryo sacs of flowers sometimes considered the gametophyte generation in an alternation of generations life cycle?

Answer 27

both structures are multicellular, and they both reproduce using gametes.

Question 28

What two types of cells are found in a pollen grain?

Answer 28

.there is at least one sperm cell, and there is a tube nucleus.

Question 29

Typically, how many cells are in an embryo sac? How many of them get fertilized?

Answer 29

.Typically, there are seven cells in an embryo sac. two of these cells get fertilized.

Question 30

What is the difference between pollination and fertilization?

Answer 30

pollination is the transfer of pollen from an anther to a stigma, while fertilization is the act of the sperms fusing with the egg and the large central nucleus in the embryo sac.

Question 31

How many sperm cells are used in plant fertilization?

Answer 31

two.

Question 32

Where does the endosperm come from? What is its purpose?

Answer 32

the endosperm comes from the fertilization of the large, two-nucleus cell that is at the center of the embryo sac. it provides nutrition for the developing embryo.

Question 33

The cotyledon or cotyledons help provide food for the plant before and often after germination. How do cotyledons accomplish each task?

Answer 33

Cotyledons either absorb the endosperm or aid in the transfer of nutrients from the endosperm to the embryo. after germination, they often perform the first photosynthesis in the plant.

Question 34

Name the three basic parts of the plant embryo and what each gives rise to in germination.

Answer 34

.the three basic parts of the radical, the hypocotyl, and the epicotyl. the radicle becomes the root, the hypocotyl the stem, and the epicotyl gives rise to the first true leaves of the plant.

Question 35

What is the purpose of a fruit?

Answer 35

a fruit allows for the dispersal of seeds to places away from the parent.

Question 36

Name at least three ways in which pollen is transferred from the stamens of one flower to the carpel of another.

Answer 36

wind, bees, beetles, birds, moths, or butterflies.

Question 37

Why are cotyledons sometimes called “seed leaves?”

Answer 37

they form leaf-life structures if they end up rising above ground with the seedling.