98 HOW ARE ANIMALS AND PLANTS DEPENDENT? 



and thus avoid capture ; (23) they all taste badly to birds ; (24) many 

 have a long quiescent period during metamorphosis ; (25) they have 

 few enemies. 



VI. Insects when they visit flowers may (26) go there to lay their 

 eggs; (27) carry pollen from one flower to another of a different 

 kind; (28) pierce holes in the flowers in order to steal nectar; 



(29) transfer pollen from the anthers of one flower to the pistil of 

 another flower of a different species, thus causing self-pollination; 



(30) carry pollen away without intending it, and thus cross-pollinate 

 flowers. 



VII. Fertilization of a flower takes place when (31) a pollen tube 

 is formed ; (32) an insect visits a flower ; (33) the sperm nucleus unites 

 with the egg cell ; (34) pollen germinates on the stigma and grows a 

 pollen tube ; (35) any two cells meet. 



VIII. Flowers have (36) essential organs called calyx and corolla ; 

 (37) stamens, pistil, petals, and sepals; (38) structures called anthers, 

 which produce pollen ; (39) organs called ovaries, which hold the egg 

 cells ; (40) the possibility of producing seeds if they are pollinated. 



IX. Effective adaptations in insects for bringing about cross-pol- 

 lination are: (41) hairs on the legs and body; (42) a long piercing 

 beak ; (43) fluffy palps, as in the butterfly ; (44) smooth bodies, as in 

 the ant ; (45) pollen baskets, as in the bee. 



X. The flowers most effectively adapted for bringing about cross- 

 pollination are : (46) flowers with only stamens or pistils ; (47) flowers 

 with essential organs of different lengths; (48) flowers having the 

 stamens and pistils ripen at different times ; (49) showy flowers with- 

 out essential organs; (50) flowers which prevent insect visitors from 

 reaching the pollen. 



Achievement Test 



1. How can you tell an insect from other animals? 



2. Where would you look for the different orders of insects ? From 

 how many of the orders of insects have you been able to find and 

 collect representatives ? 



3. How many kinds of larvae and pupae in each of the above orders 

 of insects can you name ? 



4. Have you ever studied an observation hive of bees ? Describe it. 



5. How could you make an artificial ant's nest and study the life 

 of the colony? 



