Biology Chapter 47

model organisms

fertilization

acrosomal reaction

fast block to polyspermy

slow block to polyspermy

cortical reaction

a rise in ca2+ causes:

zona pellucida

cleavage

the smaller cells that cleavage creates are called:

blastula

blastocoel

holoblastic

meroblastic

morphogenesis

gastrulation

organogenesis

gastrula

cell layers produced by gastrulation are called:

ectoderm

endoderm

mesoderm

archenteron

blastopore

dorsal lip

vegetal pole

animal pole

primitive streak

blastocyst

4 stages in early embryonic development in humans:

trophoblast

mammals and reptiles and birds are called:

notochord

neural tube

neural crest

somites

differentiation

totipotent

The first stage of embryonic development is _____. This process produces _____. cleavage ... a cluster of cells gastrulation ... a three-layered embryo parturition ... a fetus ovulation ... a zygote neurulation ... a neurula

Tissue and organ formation begins during the process of organogenesis. Which five of the following statements are true about organogenesis in a frog embryo? The notochord forms from mesoderm and develops into the central nervous system. The mesoderm gives rise to the epidermis of the frog's skin. The neural tube forms from ectoderm and develops into the central nervous system. The endoderm gives rise to the lining of the frog's digestive tract. Somites form along the length of the notochord and neural tube. The notochord does not persist in adult frogs. Some somite cells migrate to other locations in the developing embryo.

In animal development, which of the following best describes the process of cleavage? Meiosis Differentiation Mitosis Fertilization

What are the cells created by cleavage called? Blastopores Blastomeres Blastulas Blastocoels

Which of the following are the three germ layers contained in the gastrula? Ectoderm, mesoderm, epidermis Ectoderm, mesoderm, endoderm Ectoderm, mesoderm, echinoderm Ectotherm, mesoderm, endoderm

Which of the following stages of development is defined by the three embryonic tissue layers (ectoderm, mesoderm, and endoderm)? Zygote Blastula Gastrula Yolk

What happens to a cell during the process of differentiation? Material moves across the cell membrane from a region of higher concentration to a region of lower concentration. It undergoes a change toward a more specialized form or function. It divides to produce a cell with the same number of chromosomes. It divides to produce a cell with one-half the number of original chromosomes.

A child is born without a fully developed pancreas. He is normal in all other respects, and thus doctors believe that the problem most likely began early in development. During which of the following processes did the original error most likely occur? Endoderm formation Ectoderm formation Cleavage Mesoderm formation

True or false? Early animal development progresses through distinct stages: first the production of the zygote through fertilization, then cleavage, then the formation of the gastrula, and then the formation of the blastula. True False

In sea urchins, the process of fertilization produces a(n) _____. archenteron morula gastrula gamete zygote

What is the cortical reaction? the formation of a fertilization envelope that bars additional sperm from entry into the egg the release of hydrolytic enzymes from the sperm cell a depolarization of the eggs' plasma membrane so that only one sperm cell can fuse with it a series of rapid mitotic divisions that follow fertilization the process that forms a three-layered embryo

As cleavage continues, a zygote forms into a solid multicellular ball called a(n) _____. endometrium morula trophoblast gastrula blastula

Several hours after fertilization, cleavage results in the formation of a hollow ball of cells called a _____. blastomere morula trophoblast gastrula blastula

The three-layered embryo is the _____. archenteron morula trophoblast gastrula blastula

The _____ eventually develops into the sea urchin's digestive tract. blastocoel archenteron blastomere ectoderm blastopore

During gastrulation, invagination occurs at the _____. archenteron blastocoel endometrium blastopore trophoblast

In vertebrates, the ectoderm gives rise to the _____. skeleton circulatory system outer layer of skin lining of the digestive tract pancreas

During gastrulation in frogs, a rod of mesoderm under the dorsal surface forms the _____. notochord ectoderm endoderm archenteron blastopore

During gastrulation in frogs, cells from the animal pole spread over the embryo and form the _____. endoderm ectoderm archenteron blastopore blastula

The notochord functions as a core around which mesodermal cells form the frog's _____. backbone blastopore endometrium nervous system archenteron

An ectodermal thickening above the frog's notochord forms a _____. pancreas neural plate skeleton liver lining of the stomach

The _____ is(are) formed when the neural folds join and a portion of the neural plate sinks beneath the embryo's surface. archenteron anus back muscles neural tube digestive system

The enlarged anterior portion of the neural tube will develop into a frog's _____. spinal cord tongue reproductive system outer layer of skin brain

The posterior portion of the neural tube will develop into the frog's _____. spinal cord brain blastocoel digestive tract anus

The mesoderm gives rise to _____. the central nervous system skeletal and muscular systems the gastrointestinal tract and pancreas the lining of the lungs jaws and teeth

Birds, reptiles, and mammals are called "amniotes" because _____. they digest yolk and form a network of blood vessels to distribute nutrients to the embryo their embryos lack an allantois to collect and store metabolic wastes they transport oxygen to the embryo they have extra-embryonic membranes that develop an aqueous environment in which development occurs they give rise to cells that form the nervous system

Embryonic cells especially active in assuring nutritional exchange between a pregnant woman and her embryo are found in the _____. epiblast hypoblast trophoblast ectoderm inner cell mass

An embryonic cell that is "totipotent" is one that can _____. organize the blastula redistribute yolk from the vegetal to the animal pole of the frog embryo move mesoderm cells in the blastocoel migrate into the center of the blastula during gastrulation by itself, give rise to the entire embryo, as cleavage proceeds

Choose the correct developmental sequence of animal development. organogenesis ? cleavage ? fertilization ? gastrulation gastrulation ? cleavage ? fertilization ? organogenesis cleavage ? fertilization ? gastrulation ? organogenesis cleavage ? gastrulation ? organogenesis ? fertilization fertilization ? cleavage ? gastrulation ? organogenesis

Among the following, the earliest consequence of the acrosomal reaction is _____. the membrane of the egg depolarizing the development of the fertilization envelope the slow block to polyspermy cleavage the cortical reaction

The uneven cleavage of cells early in the development of the yolk-rich embryos of birds is called _____. gastrulation holoblastic cleavage meroblastic cleavage neurulation organogenesis

Even in the absence of sperm, metabolic activity in an egg can be artificially activated by _____. depletion of its ATP supplies abnormally high levels of carbonic acid in the cytosol abnormally low levels of extracellular oxygen injection of calcium ions into the cytosol

The formation of the fertilization envelope requires an increase in the availability of _____. sodium ions potassium ions hydrogen ions calcium ions

Contact of a sea urchin egg with signal molecules on sperm causes the egg to undergo a brief _____. membrane depolarization mitosis vitellogenesis acrosomal reaction

The plasma membrane of the sea urchin egg _____. releases calcium, which initiates the cortical reaction is a mesh of proteins crossing through the cytosol of the egg is outside of the fertilization membrane has receptor molecules that are specific for binding acrosomal proteins

Fertilization of an egg without activation is most like _____. preparing a pie from scratch and baking it in the oven placing the key in the ignition of a car but not starting the engine resting during halftime of a basketball game walking to the cafeteria and eating lunch

A reproductive difference between sea urchins and humans is _____. sea urchins, but not humans, have a need to block polyspermy, because only in sea urchins can there be more than one source of sperm to fertilize the eggs the sea urchin egg completes meiosis prior to fertilization, but meiosis in humans is completed after fertilization sea urchin eggs and sperm are of equal size, but human eggs are much bigger than human sperm sea urchin zygotes get their mitochondria from the sperm, but human zygotes get their mitochondria from the egg

During fertilization, the acrosomal contents _____. block polyspermy help propel more sperm toward the egg digest the protective jelly coat on the surface of the egg trigger the completion of meiosis by the sperm

In a newly fertilized egg, the vitelline layer _____. reduces the loss of water from the egg and prevents desiccation provides most of the nutrients used by the zygote lifts away from the egg and hardens to form a fertilization envelope secretes hormones that enhance steroidogenesis by the ovary

In sea urchins, the "fast block" and the longer lasting "slow block" to polyspermy, respectively, are _____. membrane depolarization and the cortical reaction the jelly coat of the egg and the vitelline membrane the acrosomal reaction and the formation of egg white the cortical reaction and the formation of yolk protein

In an egg cell treated with a chemical that binds calcium and magnesium ions, the _____. fertilization envelope would not be formed acrosomal reaction would be blocked fusion of sperm and egg nuclei would be blocked fast block to polyspermy would not occur

In mammalian eggs, the receptors for sperm are found in the _____. cytosol of the egg fertilization membrane mitochondria of the egg egg plasma membrane

A human blastomere is _____. a cell that contains a (degenerating) second polar body an embryonic cell that is smaller than the ovum that part of the acrosome that opens the egg's membrane an embryonic structure that includes a fluid-filled cavity

At the moment of sperm penetration, human eggs _____. are still surrounded by follicular cells have a paper-thin cell of calcium carbonate that prevents desiccation have used flagellar propulsion to move from the ovary to the oviduct are still located within the ovary

In a developing frog embryo, most of the yolk is _____. found within the cleavage furrow located near the animal pole distributed equally throughout the embryo located near the vegetal pole

Among these choices, the largest cell involved in frog reproduction is _____. one of the products of the first cleavage a blastomere in the animal pole an egg a blastomere in the vegetal pole

The pattern of embryonic development in which only the cells lacking yolk subsequently undergo cleavage is called _____. meroblastic development, which is typical of birds holoblastic development, which is typical of marsupial mammals holoblastic development, which is typical of amphibians meroblastic development, which is typical of humans

As cleavage continues during frog development, the size of the blastomeres _____. decreases as the number of the blastomeres decreases increases as the number of the blastomeres decreases increases as the number of the blastomeres increases decreases as the number of the blastomeres increases

The vegetal pole of a frog zygote differs from the animal pole in that _____. the vegetal pole cells undergo mitosis, but not cytokinesis the polar bodies bud from this region the blastomeres originate only in the vegetal pole the vegetal pole has a higher concentration of yolk

Meroblastic cleavage occurs in _____. humans, but not in sea urchins or birds sea urchins, but not in humans or birds both sea urchins and birds, but not in humans birds, but not in sea urchins or humans

h of the following correctly displays the sequence of developmental milestones? cleavage ? blastula ? gastrula gastrula ? blastula ? cleavage cleavage ? gastrula ? blastula blastula ? gastrula ? cleavage

The first cavity formed during frog development is the _____. anus mouth blastopore blastocoel

In some rare salamander species, all individuals are females. Reproduction relies on those females having access to sperm from males of another species. However, the resulting embryos receive no genetic contribution from the males. In this case, the sperm appear to be used only for _____. egg activation the creation of a diploid cell cell differentiation morphogenesis

The cortical reaction of sea urchin eggs functions directly in _____. the release of hydrolytic enzymes from the sperm the generation of an electrical impulse by the egg the formation of a fertilization envelope the production of a fast block to polyspermy

The structure of the Drosophila gene, called Tinman, is similar to a gene in humans that also _____. specifies the location of the heart specifies limb elongation points promotes ear development determines structures in the eyes

From earliest to latest, the overall sequence of early development proceeds in which of the following sequences? cortical reaction ? acrosomal reaction ? first cell division synthesis of embryo's DNA begins cortical reaction ? synthesis of embryo's DNA begins ? acrosomal reaction ? first cell division acrosomal reaction ? cortical reaction ? synthesis of embryo's DNA begins ? first cell division first cell division ? synthesis of embryo's DNA begins ? acrosomal reaction ? cortical reaction

During the early development of a human embryo, the _____ eventually forms the _____. epiblast ... ectodermal, mesodermal, and endodermal tissues blastocoel ... archenteron trophoblast ... embryo proper epiblast ... placenta hypoblast ... amniotic cavity

Cells move to new positions as an embryo establishes its three germ-tissue layers during _____. gastrulation induction cleavage determination

Which of the following is a correct description of the fate of the germ layers? The ectoderm gives rise to the liver. The mesoderm gives rise to the notochord. The mesoderm gives rise to the lungs. The endoderm gives rise to the hair follicles.

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is _____. ectoderm ? mesoderm ? endoderm ectoderm ? endoderm ? mesoderm mesoderm ? endoderm ? ectoderm endoderm ? ectoderm ? mesoderm

If gastrulation was blocked by an environmental toxin, then _____. cleavage would not occur in the zygote the blastula would not be formed embryonic germ layers would not form the blastopore would form above the gray crescent in the animal pole

In a frog embryo, gastrulation _____. proceeds by involution as cells roll over the lip of the blastopore occurs along the primitive streak in the animal hemisphere produces a blastocoel displaced into the animal hemisphere occurs within the inner cell mass that is embedded in the large amount of yolk

The primitive streak in a bird is the functional equivalent of _____. the notochord in a mammal the lip of the blastopore in the frog the archenteron in a frog neural crest cells in a mammal

In all vertebrate animals, development requires _____. extraembryonic membranes a large supply of yolk an aqueous environment a primitive streak

At the time of implantation, the human embryo is called a _____. gastrula blastocyst zygote fetus

Uterine implantation due to enzymatic digestion of the endometrium is initiated by the _____. endoderm mesoderm inner cell mass trophoblast

From earliest to latest, the overall sequence of early development proceeds in which of the following sequences? preformation ? morphogenesis ? neurulation gastrulation ? organogenesis ? cleavage gastrulation ? blastulation ? neurulation cleavage ? gastrulation ? organogenesis

Changes in cell position occur extensively during _____. cleavage, but not during gastrulation or organogenesis organogenesis, but not during gastrulation or cleavage gastrulation and cleavage gastrulation

The embryonic precursor to the human spinal cord is the _____. notochord neural tube mesoderm archenteron

Which of the following is common to the development of birds and mammals? the formation of an embryonic epiblast and hypoblast the formation of an embryonic yolk plug the formation of an embryonic trophoblast the formation of an embryonic gray crescent

The archenteron of a frog develops into the _____. placenta blastocoel endoderm lumen of the digestive tract

The cortical reaction of sea urchin eggs functions directly in the release of hydrolytic enzymes from the sperm. the fusion of egg and sperm nuclei. the generation of an electrical impulse by the egg. the production of a fast block to polyspermy. the formation of a fertilization envelope.

Select the correct statement about embryonic development in a frog. The reorganization of cell layers during gastrulation allows the layers to interact with each other in new ways. The blastocoel of a developing frog embryo develops into the digestive tract. Development from zygote to blastula involves mitotic division, cell movement, and cell growth.