Plz help I will mark you brainlist plz I don't know what to do

Crossing over and independent assortment are important activities that occur during meiosis. what is the significance of these activities

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

With regard to enzymes, key is to lock as a) substrate is to activation energy eliminate b) product is to substrate. c) enzyme is to active site. d) substrate is to active site.