According to the graph, the coral growth was at its peak at 10 meters and a temperature of 20 degrees Celsius.

A. 10 meters; 20 degrees Celsius

According to the graph, the coral growth was at its best at a temperature that falls between 18 to 23 degrees Celsius.

D. This coral grows best from 18 to 23 degrees Celsius.

There are three known germ layers that arise during embryonic development and they are called **ectoderm, mesoderm, and endoderm**.

**Endoderm** is one of the primary germ layers composed of a various mass of cells found in the embryo of a vertebrate organism. It is located in the innermost portion and develops into the gut and other internal organs of the body.

**Mesoderm** is another primary germ layer that is found between the endoderm and the ectoderm. The fate of this germ layer is the formation of the muscles, bones, and blood vessels.

**Ectoderm** is the last and the outermost germ layer and it later forms the skin, sweat glands, other receptors found in the integumentary system, and the lining of the body cavity.

Hence, the correct answer is **E**

**Sponges** are described as multicellular, heterotrophic animals, having spicules as their skeletal structure. However, they do not have cell walls and they are considered sessile organisms. They have radial symmetry meaning they have similar parts that are arranged regularly around the central axis. Hence, the correct answer is **C**

C

**Animals** are **heterotrophic species** that function to carry various living processes including feeding, respiration or breathing, blood circulation, response, and reproduction. These organisms are eukaryotic multicellular, and they lack cell walls. They have high levels of specialization and internal organization which makes them a higher form of species.

Hence, the correct answer is **A**. Since animals are considered heterotrophic organisms, meaning they cannot synthesize or produce their own food and rather depend on other organisms for their nutrition.

A

In most animals, they reproduce sexually by the fusion of a sperm and an egg cell. Sperm cells and egg cells are haploid gametes that are produced by meiosis.

D. haploid gametes

The production of gemmules is a characteristic of a sponge. Polyps and medusas are found in cnidarians.

D. II and III only

A blastula is made up of hollow ball of cells that form during an animal’s early stage of development.

E. Blastula

The term protostome refers to the animals, which are mostly invertebrates, having a mouth that is formed by the blastophore.

B. Protostome

Osculum is responsible for expelling the water in a living sponge.

A. Osculum

In sponges, the food is digested by specialized cells called archaeocytes. They move around the walls of the sponge to transport the nutrients to the other cells.

C. Archaeocyte