Answer: check your notes or ask a parent.
Explanation: ok if you are doing a lesson or test then first search wiki of plant systems. Then you will see variety pf stuff and you will come across your answer to your question. Always take notes because on day, it will help you. Also if wiki dosrnt answer it then try asking your parent, or a teacher.
Helicase molecules is active first in DNA replication. DNA helicase are enzymes capable of unwinding duplex DNA to provide the single- stranded DNA templates that are required in processes such as replication and recombination.all helicase separates the strands double mix helix using energy derived from hydrolysis nucleotide.
Many cacti have roots that spread out widely, but only penetrate a short distance into the soil. In one case, a young saguaro only 12 cm (4.7 in) tall had a root system with a diameter of 2 m (7 ft), but no more than 10 cm (4 in) deep.
In other words they can't penetrate that deep.