Which row gives the definition of active transport?
- Acell membrane needed: no; movement of ions: down a concentration gradient; respiration needed: yes
- Bcell membrane needed: no; movement of ions: up a concentration gradient; respiration needed: no
- Ccell membrane needed: yes; movement of ions: down a concentration gradient; respiration needed: no
- Dcell membrane needed: yes; movement of ions: up a concentration gradient; respiration needed: yes