Green algae and land plants share three characteristics. They produce their own food through photosynthesis, they have eukaryotic cells that contain chlorophyll, and they .

Green algae and land plants share three characteristics. They produce their own food through photosynthesis, they have eukaryotic cells that contain chlorophyll, and they have cell walls made up of cellulose.

Explanation:

Green algae and land plants have a lot of similarities like both their cells are eukaryotic and have nucleus, mitochondria and other cell organelles and contain chlorophyll (prepare own food by photosynthesis).

The cells of green algae are covered by a protective cell wall which contains a polymer similar to that of the land plants cell wall containing cellulose and/or glycoproteins. This cellulose is a polysaccharide carbohydrate.

The presence of cell wall in green algae proves that they are the closest relative or ancestors for land plants.

the reason the two sea urchins don't compete with each other for food, resources, etc. is because the urchins have adapted to the environment but they have also adapted to each other. this is most likely because the genes of the sea urchins.

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.