1: NATURE AND SCOPE OF DEVELOPMENT

interdisciplinary field that is at foundation of biology accdg. to Barresi and Gilbert 2020

Seeks to elucidate the cellular and molecular mechanism that drive changes in cells, tissues and organs over time - a timescale that spans all of life, from fertilization to aging.

First known embryologist

Aristotle undertaken the first known study of _

Aristotle’s On the Generation of Animals on life cycle themes:

• born from eggs

• born by live birth

• born by producing an egg that hatches inside the body

2 major cell division Aristotle identified by which embryos are formed

Patter of cleavage (in which the entire egg is divided into successively smaller eggs, as it is in frogs and mammals)

pattern of cleavage (as in chicks, wherein only part of the egg is destined to become the embryo, while the other portion—the yolk—serves as nutrition for the embryo)

concluded that all animals—even mammals—originate from eggs

“all from egg” is the motto on the frontispiece of Harvey’s On the Generation of Living Creatures, and this precluded the spontaneous generation of animals from __

William Harvey was the first to see the ____ (the small region of the egg containing the yolk-free cytoplasm that gives rise to the embryo)

William Harvey was the first to notice that ____ before the heart does

he also suggested that the amniotic fluid might function as a “shock absorber” for the embryo

published the first microscopic account of chick development

Marcello Malpighi for the first time, the groove of the forming ____, the ____, and the ____ of the arteries and veins—to and from the yolk—were identified

built a microscope; discovered sperms in human semen

saw the mammalian egg under microscope

postulated that egg and sperm cells are equivalent

discovered the fusion of sperm and egg nuclei during fertilization in sea urchins; provided a conceptual basis for genetic inheritance and settled the long-standing debate on the role of the egg and sperm in generation of new life

discovered and understand mitosis; great step towards understanding growth and development

founder of the science of cytogenetics