Biology 172 Quiz 9

A flower is missing petals. We would refer to such a flower as being _______ .
A. complete
B. imperfect 
C. incomplete 
D. asexual
E. unisexual 

A fruit almost always includes 
A.one or more seeds 
B.the ovary wall 
C.brightly colored pigments to attract animal dispersers 
D.fleshy cells rich in sugars
E.both A and B

A mature angiosperm pollen grain (before pollen tube formation) is composed of _____ cell(s).
A. three 
B. four 
C. one
D. five
E. two 

A mutation in which of the following floral parts would have the greatest impact on pollination?
A.sepal 
B.petal 
C.stamen 
D.carpel
E.either C or D

The endosperm of a seed functions primarily to
A. carry out photosynthesis while the seed is dormant 
B. attract pollenating insects to the flower 
C. store nutrients for the developing plant embryo 
D. attract the sperm nuclei to the egg in the ovule
E. absorb water causing the seed embryo to expand and break out of the seed coat 

What is typically the result of double fertilization in angiosperms? 
A. Two embryos develop in every seed. 
B. A triploid zygote is formed. 
C. The fertilized antipodal cells develop into the seed coat.
D. Both a diploid embryo and triploid endosperm are formed. 
E. The endosperm develops into a diploid nutrient tissue.

Which of these structures is unique to the seed of a monocot? 
A. seed coat 
B. endosperm 
C. cotyledon 
D. radicle
E. coleoptile

Which is NOT a component of a carpel? 
A. style
B. megasporangium 
C. ovary 
D. sepal
E. stigma 

A long-day plant will flower if 
A. the duration of continuous darkness is less than a critical length 
B. it is kept in continuous far-red light 
C. the duration of continuous light is less than a critical length 
D. the duration of continuous darkness exceeds a critical length
E. the duration of continuous light exceeds a critical length

Both red and blue light are involved in 
A. tracking seasons.
B. stem elongation. 
C. photoperiodism. 
D. positive phototropism. 
E. all of the above

Ethylene, as an example of a plant hormone, may have multiple effects on a plant, depending on all of the following except the 
A. concentration of ethylene
B. altered chemical structure of ethylene from a gas to a liquid 
C. site of action within the plant 
D. developmental stage of the plant
E. readiness of cell membrane receptors for the ethylene 

If a short-day plant has a critical night length of 15 hours, then which of the following 24-hour cycles will prevent flowering? 
A. 6 hours light/2 hours dark/light flash/16 hours dark
B. 8 hours light/16 hours dark 
C. 8 hours light/8 hours dark/light flash/8 hours dark 
D. 4 hours light/20 hours dark 
E. 2 hours light/20 hours dark/2 hours light

One effect of gibberellins is to stimulate cereal seeds to produce 
A. amylase 
B. starch
C. RuBP carboxylase
D. abscisic acid 
E. lipids 

Which of the following hormones would be most useful in promoting the rooting of plant cuttings? 
A. cytokinins 
B. oligosaccharins
C. gibberellins 
D. auxins
E. abscisic acid

We know from the experiments of the past that plants bend toward light because 
A. the sun stimulates stem growth
B. auxin is inactive on the dark side of the stem 
C. phytochrome stimulates florigen production 
D. cell expansion is greater on the dark side of the stem 
E. they need sunlight energy for photosynthesis

A generative cell and a tube cell originate when _____.

As leaf lettuce matures, a tall flowering shoot extends beyond the basal edible leaves. After the plant bolts like this, it no longer produces broad, tasty leaves. Suppose you want to prevent bolting so that you can harvest lettuce longer. You may want to prevent the plant from synthesizing _____.