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Question
The current extinction rate is estimated to be at least how much greater than the background extinction rate?a. 2
b. 5
c. 10
d. 50
e. 100
Answer
This answer is hidden. It contains 1 characters.
Related questions
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Glandular epithelium
Choose the one most appropriate response for each.
a. ligaments and tendons are made of this
b. contains collagen and elastin; acts as a packing material that supports internal organs
c. receives, conducts, and initiates signals in response to environmental changes
d. stores fat
e. offers resistance to mechanical injury and loss of internal fluids; also a barrier against microorganisms
f. secretes extracellular products such as sweat, mucus, tears, and saliva
g. fluid ground substance plus free cells; involved in transport, pH, and temperature stability
h. extracellular fluid that bathes cells and tissues
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Which of the following is NOT found in the epidermis?
a. stratified epithelium
b. blood vessels
c. adhering cell junctions
d. keratin
e. melanin
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Of the following organs, which is NOT in the abdominal cavity?
a. stomach
b. liver
c. heart
d. intestine
e. pancreas
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The maintenance of the volume and composition of body fluids is the primary responsibility of which system?
a. integumentary
b. immune
c. digestive
d. urinary
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The endocrine system functions in
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b. contraction.
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The following questions refer to the figure above of epithelial tissues.
This tissue is found in the gut.
a. A
b. B
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__________ is a response to changes in length of night relative to length of day.
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Respond to the following statements in reference to the five plant hormones listed below.
a. auxins
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c. cytokinins
d. abscisic acid
e. ethylene
This hormone promotes bud and seed dormancy.
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Circadian
Choose the one most appropriate answer for each. Some letters may not be used.
a. flower each successive year or after several years of vegetative growth
b. promotes cell elongation in stems
c. has receptor sites for a particular hormonal message
d. a hollow, cylindrical organ that protects young leaves growing within it
e. blue-green pigment that absorbs light energy
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Gibberellin
Choose the one most appropriate answer for each. Some letters may not be used.
a. flower each successive year or after several years of vegetative growth
b. promotes cell elongation in stems
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Coleoptile
Choose the one most appropriate answer for each. Some letters may not be used.
a. flower each successive year or after several years of vegetative growth
b. promotes cell elongation in stems
c. has receptor sites for a particular hormonal message
d. a hollow, cylindrical organ that protects young leaves growing within it
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Biennial
Choose the one most appropriate answer for each. Some letters may not be used.
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c. has receptor sites for a particular hormonal message
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Which plant hormone listed below is responsible for the symbiotic relationship shown in the above figure?
a. auxin
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a. the biological clock.
b. vernalization.
c. photoperiodism.
d. biennial life cycle.
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Plants cannot ____ in the dark.
a. grow
b. respire
c. move
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a. far red
b. red
c. yellow
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b. gibberellin.
c. cytokinin.
d. abscisic acid.
e. ethylene.
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a. auxin.
b. gibberellin.
c. cytokinin.
d. abscisic acid.
e. ethylene.
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The polar transport of auxin in a plant
a. creates an uneven distribution of the hormone.
b. uses active membrane transporters to move auxin in and out of cells.
c. uses membrane pumps to move hydrogen ions out of the cytoplasm into the primary cell wall.
d. activates enzymes that loosen cross-links between cellulose microfibrils.
e. does all of these.
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Auxin concentration gradients
a. appear once germination begins.
b. promote the transcription of an enzyme that breaks down cytokinin.
c. allow formation of plant parts in expected patterns.
d. help young cells elongate so that shoots and roots lengthen.
e. are described by all of these EXCEPT "appear once germination begins."
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Root formation in stem cuttings can be improved by the application of
a. synthetic auxins.
b. abscisic acid.
c. salicylic acid.
d. citric acid.
e. nitric acid.
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a. produce growth hormones.
b. use aerobic respiration.
c. move when conditions around it deteriorate.
d. produce its own lipids and proteins.
e. respond to dwindling supplies of nutrients and water.
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A pollen grain coat is composed of which of the following?
a. sporopollenin
b. cellulose
c. peptidoglycan
d. exopolysaccharides
e. none of these
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Sperm nuclei are indicated by
a. A.
b. B.
c. C.
d. D.
e. E.
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Meiosis is indicated by
a. A.
b. B.
c. C.
d. D.
e. E.