________ occurs when sperm and egg interact.
______ is cell division without growth.
In the lancelet, the zygote undergoes cleavage forming a solid ball of cells of uniform size, called a ________.
The ______ is the primitive digestive tract or gut.
The third layer to form in gastrulation is the _____________.
The development of all organs can be traced to one of the germ layers.
Ectoderm cells will become the skeletal and muscular systems.
The nervous system develops from the ____________.
|D)||portions of all of the above|
The chick has solved the problem of reproduction on land by providing a great deal of _______.
|A)||additional cell cleavage|
|B)||yolk within a pool of fluid|
|C)||yolk within a hard shell|
|D)||water inside the coelom to substitute for the dry environment|
|E)||water in its bloodstream|
The anterior end of the neural tube develops into the _________.
______ give(s) rise to segmental muscles of the body and also produce(s) the vertebral bones.
|C)||The neural tube|
The coelom is completely lined by ___________.
All chordates have an embryo with _________.
|A)||a dorsal hollow nerve cord|
|C)||a coelom lined with mesoderm|
|D)||all of the above|
Development requires __________.
|A)||cellular cleavage and fusion|
|B)||growth, cellular differentiation and morphogenesis|
|C)||ooplasmic fusion and segregation|
|D)||neurulation and induction|
|E)||gastrulation and neurulation|
Cell differentiation occurs when cells become specialized in structure and function.
Differentiation and morphogenesis account for specialization of tissues and formation of organs and determine the shape of the organism.
The cytoplasm of a frog's egg is uniform.
A cell does NOT need the gray crescent to develop into a tadpole.
The formation of the germ layers is probably influenced by environmental factors.
_________ is the ability of one tissue to influence the development of another.
|B)||Homeotic gene pattern formation|
The presumptive notochord tissue can cause the tissue under the belly ectoderm to develop into a neural plate.
Direct contact or the production of a chemical acts as a signal that activates certain _____ in neighboring cells and brings about development of particular structures.
It is believed that induction stops after neural tube formation.
The homeodomain proteins stay in the nucleus and regulate transcription of other genes during development.
_____________ genes are involved in pattern formation and many contain the same sequence of nucleic acids across a wide range of species.
Homeotic genes that contain the same particular sequence of nucleotides are called a ______.
In the chick, the ______ lies next to the shell and carries on gas exchange.
The ______ collect(s) nitrogenous waste in the chick.
The presence of extraembryonic membranes in reptiles made development on land possible.
Extraembryonic membranes are found during the development of humans but not during the development of chicks.
Embryonic development includes the first __________ of development in humans.
In humans, cleavage begins in the _________.
|E)||early stages of childbirth|
The trophoblast gives rise to the __________.
In the third week, the embryo begins implanting in the wall of the uterus.
___________ is the hormone that is the basis for the pregnancy test.
|B)||Human chorionic gonadotropic hormone (HCG)|
Gastrulation occurs during the second week of embryonic development in humans.
Gastrulation occurs during the second week and the inner cell mass flattens into the _________ composed of ectoderm and endoderm.
|A)||gill or lung|
|B)||neural fold or groove|
In humans, the fourth pair of pharyngeal pouches become _________.
|B)||the thymus gland|
|D)||all of the above|
The ______ system is the first organ system to be visually evident in human embryonic development.
Development of the heart begins in the ______ week of human embryonic development.
The blood vessels of the allantois become the __________ .
|C)||dorsal aorta and vena cava|
During the fourth and fifth months, human features--arms and legs, ears, eyes and nose--begin to appear.
Three months after the embryo is fully implanted, the placenta begins to form.
The placenta produces __________.
|C)||estrogen and progesterone|
|D)||gonadotropic releasing hormone (GnRH)|
|E)||follicle-stimulating hormone (FSH)|
The placenta has a fetal side and a maternal side.
Umbilical arteries carry ______ blood to the placenta.
|C)||mixed maternal and fetal|
The fetus receives its oxygen and nutrients from the mother's blood by way of _________.
|A)||extended respiratory and digestive tubes from the mother's organ systems|
|B)||mixing fetal and maternal blood in the placenta|
|C)||the placenta without blood exchange|
|D)||storage of nutrients in yolk and diffusion of oxygen across the amniotic fluid|
Parturition (labor and expulsion of the fetus) is considered to have ______ stage(s).
Hormones that cause the uterus to contract are ___________.
|A)||estrogen and progesterone|
|B)||oxytocin and prostaglandins|
|C)||prolactin and progesterone|
|D)||FSH and LH|
The placenta is delivered during the second stage of labor.
___________ is another term for milk production.
______ is the study of aging.
In a menopausal woman, there is plenty of FSH in the bloodstream, but the ovaries do NOT respond.
The cause(s) of aging has/have been attributed to ____________.
|A)||genes since cell divisions are limited and vary by species and some people with long-lived parents live longer themselves|
|B)||a whole body process since tissues decline in function|
|C)||extrinsic factors such as lack of calcium, a good diet, or exercise|
|D)||the accumulation of damage from free radicals or unstable molecules|
|E)||all of the above|