Please answer 3 plz

7th grade science

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

What will most likely happen in the absence of a cell membrane? a) photosynthesis will not take place. b) the cell will not store food, water, nutrients, and waste. c) energy will not be released during cellular respiration. d) substances will pass in and out of the cell in an uncontrolled manner.

Convert the temperature of dry ice, –77 ∞c, into degrees fahrenheit and kelvin.