Exam 1: Development and Structure of Cells and Tissues

Which phase of the cell cycle is characterized as the initial resting stage?

Posttranslational modifications to proteins produced by the rough endoplasmic reticulum are accomplished by __________.

Tissues are most susceptible to teratogens during the proliferative period.

The foramen ovale closes during the third week of prenatal life.

Which organelle produces microtubules?

The ovum contains twice as many chromosomes as its parent cell.

___________bone formation occurs directly through a tight matrix of collagen fibers,which slowly calcify into bone.

Spindles present during mitosis are attached to centromeres.

Before the development of the vascular system,the vitelline system provides nutrients to the embryo.

The embryonic skeleton first forms as bone.

Myotome produces ___________ tissue.

Which chemical is called the second messenger?

Smooth muscle is consciously controlled.

Each tissue originates from mesoderm,except one.What is the exception?

Mitochondria produce which chemical for intracellular energy?

Endoderm and ectoderm are the first two germ layers to develop.

Intercalated disks are present in which type of muscle?

Blood cells begin to form in the __________ __________ at weeks of development.

Melanocytes are responsible for skin pigment.

___________ __________appear in the third prenatal week as the first sign of shape change in the embryo's body.