Answer:
A. Chelicerates are a group of arthropods
E. Sea urchins are a group of echinoderms
B. Gastropods are a group of mollusks
Explanation:
Chelicerates are primitive arthropods having 6 pairs of appendages. 1 oral appendage used for feeding and lack actual mouth parts for chewing up "suck up predigested food". Cephalothorax is the largest and Abdomen contains gills.
Sea urchins are a group of echinoderms as they have spin skin , all marine and found in the bottom of the sea.
Gastropods are the largest and most varied group of molluscs. Gastropod means stomach footed, a typical gastropod is a coiled mass of organs enclosed in a dorsal shell, which rests on the foot having a head ans sensory structures on head and having an operculum.
<h3><u>Answer;</u></h3>
<em>The marrow in the bones of the skeletal system helps produce the cells in the blood, which is the key fluid of circulatory system</em>
<h3><u>Explanation;</u></h3>
- <em><u>Skeletal system is a system in the body that is made up of cartilage and calcified bone that work together by helping in the smooth movement process of the body. </u></em>
- <em><u>Circulatory system on the other hand is a system of the body that is made up of blood vessels that carry blood away and towards the heart. The system helps in transport of oxygen and nutrients in all the body tissues, and also transport of carbon dioxide and wastes out of the tissues.</u></em>
- <em><u>The calcified bones of the skeletal system work with the circulatory system, such that the bone marrow in these bones helps in the production of blood cells such as red blood cells and white blood cells.</u></em>
After a molecule of DNA replicates, two double-stranded molecules are formed. This results in a total of four strands of DNA.
The highest between 25 and 50;the lowest between 55 and 74
