| A | B |
|---|
| stigma | top portion of the carpel |
| style | part of carpel |
| carpel | female reproductive unit of the flower |
| pollen tube | grows to reach the ovule, contains 2 sperm cells |
| pollination | the transfer of pollen grains from anther to stigma |
| anther | where microspores are produced |
| coevolution | occurs when 2 organisms form an interdependent relationship & affect the course of one another's evolution |
| germination | resumption of growth by an embryo or spore; occurs when a seed or spore sprouts |
| photoperiodism | the response of plants to the duration & time of light & dark |
| phytochrome | the photoreceptor of photoperiodism |
| circadian rhythms | regular periodicities in growth or activities, that approximate the 24-hr day & are reset by the rising & setting of the sun |
| nastic movements | temporary & reversible; occur in response to external stimuli, but the direction of movement is independent of the direction of the stimulus |
| tropisms | directional growth response` |
| phototrophism | growth in response to light |
| gravitrophism | growth in respone to gravity |
| thigmotrophism | grouwth in response to a solid object |
| heliotrophism | the ability of leaves or flowers to track the sun across the sky |
| auxin | hormone involved in cell elongation, tropisms, apical dominance, & fruit development |
| gibberellins | hormones involved in stem elongation, flowering, & germination |
| cytokinins | hormones which promote cell division & differentiation, delay senescence |
| senescence | the ability to delay the aging process |
| ethylene | hormone with a role in ripening fruits apical dominance, leaf avscission, wound response, thimomorphogenesis, & senescence |
| thigmomorphogenesis | growth in response to mechanical stress |
| abscisic acid | an environmental stress hormone involved in dormancy & stomatal closure due to water stress |
