3. What does the word photoperiod describe? the length of daylight
the tilt of Earth's axis
the time of migration of various animals
the way plants grow

a. or the length of daylight

Explanation:

pho·to·pe·ri·od

/ˈfōdōˌpirēəd/

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nounBOTANY•ZOOLOGY

the period of time each day during which an organism receives illumination; day length.

( this is the definition )

The length of daylight, or also the way the plants grow. depends on what school program you use. Hope it helps :)

Explanation:

albert einstein retrieved guacamole from the galapagos islands in africa

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.