Periplanata americana shows spiral and determinate types of cleavage during embryonic development which is a feature of Protostomes.

Correct Option: B

Periplanata americana shows spiral and determinate types of cleavage during embryonic development which is a feature of Protostomes.

The vertebrates process myogenic heart which is self contractile system or autoexcitable; it will thus keep working outside the body for some time.

Correct Option: C

The vertebrates process myogenic heart which is self contractile system or autoexcitable; it will thus keep working outside the body for some time.

Only nerve cells do not form layers. These also remain structurally separate from each other. Nerve cells or neurons are the cells specialized to conduct an electrochemical current. Nerve tissue is made up of these cells and supporting cells. Epithelial tissue is made of one or a few layers of compactly arranged cells overlying a basement membrane. Glands are epithelial cells specialized to elaborate and release chemicals for use in the body. Muscle tissue is made of elongated and contractile cells called myocytes.

Correct Option: C

Only nerve cells do not form layers. These also remain structurally separate from each other. Nerve cells or neurons are the cells specialized to conduct an electrochemical current. Nerve tissue is made up of these cells and supporting cells. Epithelial tissue is made of one or a few layers of compactly arranged cells overlying a basement membrane. Glands are epithelial cells specialized to elaborate and release chemicals for use in the body. Muscle tissue is made of elongated and contractile cells called myocytes.

Voluntary muscles - under control of our will. Involuntary muscles - Not under the control of our will. Muscles of urethra also remain under voluntary control after infancy.

Correct Option: D

Voluntary muscles - under control of our will. Involuntary muscles - Not under the control of our will. Muscles of urethra also remain under voluntary control after infancy.

The structure of the abdominal wall is similar in principle to the thoracic wall. There are three layers, an external, internal and innermost layer. The vessels and nerves lie between the internal and innermost layers. The abdomen can be divided into quadrants or nine abdominal regions.

Correct Option: B

The structure of the abdominal wall is similar in principle to the thoracic wall. There are three layers, an external, internal and innermost layer. The vessels and nerves lie between the internal and innermost layers. The abdomen can be divided into quadrants or nine abdominal regions.