p.13
Fertilization and Gamete Interaction
What triggers the formation of the fertilization membrane in sea urchins?
The action of a cortical granule enzyme that causes the vitelline envelope to harden.
p.56
Hox Genes and Body Plan Development
What role do Hox genes play in gene expression?
They are master genes that control the expression of subordinate genes.
p.69
Evolutionary Developmental Biology (Evo-Devo)
What can changes during development create within a species?
Diverse variation that natural selection can act on.
p.42
Hox Genes and Body Plan Development
What role do Hox genes play in gene expression?
They are master genes that control the expression of subordinate genes.
p.56
Hox Genes and Body Plan Development
Are Hox genes homologous in diverse organisms?
Yes, they are homologous across different species.
p.12
Fertilization and Gamete Interaction
What occurs on the egg surface after the first sperm enters?
Numerous changes block the entrance to any additional sperm.
p.13
Fertilization and Gamete Interaction
What is the function of the fertilization membrane?
Acts as a permanent physical barrier to prevent polyspermy.
p.42
Hox Genes and Body Plan Development
How are Hox genes characterized across different organisms?
They are homologous in diverse organisms.
p.56
Hox Genes and Body Plan Development
What do Hox genes control in embryos?
The subdivision into regions of different developmental fates along the anteroposterior axis.
p.68
Evolutionary Developmental Biology (Evo-Devo)
What is significant about Isla Daphne Major?
It is a notable location for studies in evolution and ecology.
p.5
Fertilization and Gamete Interaction
Why are marine invertebrates like sea urchins and fishes preferred for fertilization studies?
They release large amounts of eggs and sperm that are easy to keep and study in the laboratory.
p.22
Direct vs. Indirect Development
What is direct development?
When lots of nourishing yolk is present, embryos develop into a miniature adult.
p.26
Protostome vs. Deuterostome Development
What type of coelom development do vertebrates use?
A modified version of schizocoely.
p.33
Cellular Diversity and Developmental Decisions
What occurs after embryonic cell division creates different cells?
The cells begin to influence each other's fates by induction.
p.69
Evolutionary Developmental Biology (Evo-Devo)
What factors are the two medium ground finches compared on?
Same species, same island, same age, same sex.
p.13
Fertilization and Gamete Interaction
What does polyspermy refer to?
The fertilization of an egg by multiple sperm.
p.56
Hox Genes and Body Plan Development
What is UBX/Hoxc-8?
A highly conserved transcription factor found in both invertebrates and vertebrates.
p.12
Fertilization and Gamete Interaction
What is the fertilization cone?
It forms where the sperm contacts the vitelline membrane.
p.59
Evolutionary Developmental Biology (Evo-Devo)
What role do changes in development play in evolution?
They create diverse variations that natural selection can act on.
p.59
Evolutionary Developmental Biology (Evo-Devo)
How does natural variation within a species contribute to natural selection?
Natural variation provides the traits on which natural selection can act.
p.59
Cellular Diversity and Developmental Decisions
What is the difference between variation within a species and variation between species?
Variation within a species refers to differences among individuals of the same species, while variation between species refers to differences among distinct species.
p.48
Hox Genes and Body Plan Development
What role do Hox genes play in development?
Hox genes control development and are similar across diverse groups of animals.
p.15
Fertilization and Gamete Interaction
What forms a diploid zygote nucleus?
The fusion of male and female pronuclei.
p.69
Evolutionary Developmental Biology (Evo-Devo)
What species is used as an example to illustrate variation in bill sizes?
Medium ground finches (Geospiza fortis).
p.57
Hox Genes and Body Plan Development
How is position-specific expression achieved in early embryonic development?
Through segmentation genes that establish spatial patterns of transcription factors.
p.56
Hox Genes and Body Plan Development
What is ectopic expression?
Expression of a gene in a location where it is not normally expressed.
p.6
Fertilization and Gamete Interaction
How do most marine invertebrates and fishes fertilize their eggs?
By releasing enormous numbers of sperm into the ocean.
p.6
Fertilization and Gamete Interaction
Why is species-specific recognition important in marine environments?
Many closely related species may be spawning at the same time.
p.21
Gastrulation and Germ Layer Formation
What two cavities are formed during development following cleavage?
Gut cavity (gastrointestinal tract) and fluid-filled coelom (body space).
p.21
Gastrulation and Germ Layer Formation
What does the mesoderm around the coelom produce?
Layers of muscles and internal body parts.
p.8
Fertilization and Gamete Interaction
What happens during the slow block reaction?
Fusion of cortical granules with the egg membrane, releasing contents that create an osmotic gradient.
p.22
Direct vs. Indirect Development
What is indirect development?
When little yolk is present, young develop into larval stages that can feed.
p.15
Cleavage and Early Embryonic Development
What are blastomeres?
Small, maneuverable cells formed from the large cytoplasmic mass during cleavage.
p.52
Evolutionary Developmental Biology (Evo-Devo)
What are major questions in evolutionary developmental biology?
The genetic basis of developmental instructions and the role of developmental evolution in the history of life.
p.30
Cellular Diversity and Developmental Decisions
What is totipotency?
The ability of a zygote to develop into all cell types found in the adult.
p.29
Protostome vs. Deuterostome Development
What is ecdysis?
The shedding of the cuticle.
p.42
Hox Genes and Body Plan Development
What is the significance of inductive signals in vertebrate limb formation?
Inductive signals play a major role in pattern formation, which is the development of an animal's spatial organization.
p.57
Evolutionary Developmental Biology (Evo-Devo)
What is the difference between variation within a species and variation between species?
Variation within a species is derived from genetic differences among individuals, while variation between species involves distinct genetic traits that separate species.
p.45
Cellular Diversity and Developmental Decisions
What usually involves changes in the shape of a cell?
Reorganization of the cytoskeleton.
p.6
Fertilization and Gamete Interaction
What is the first step when sea urchin sperm finds an egg?
It has to penetrate a jelly layer around the egg.
p.58
Hox Genes and Body Plan Development
What is the role of Hox genes in development?
Differences in Hox gene expression patterns result in major differences in body plans.
p.14
Fertilization and Gamete Interaction
What prevents additional sperm from binding to the egg in mammals?
The cortical reaction releases enzymes that modify the egg surface.
p.31
Cellular Diversity and Developmental Decisions
What effect do cytoplasmic determinants have on blastomeres?
They set up differences in blastomeres resulting from cleavage.
p.48
Evolutionary Developmental Biology (Evo-Devo)
How does evolution affect organisms?
Organisms become different as a result of changes in the genetic control of development.
p.10
Fertilization and Gamete Interaction
What occurs in the zygote after the fusion of pronuclei?
Several cytoplasmic changes to prepare for cleavage.
p.41
Cellular Diversity and Developmental Decisions
What are the key components of building a body plan?
Cell movement, changes in adhesion, and cell proliferation.
p.60
Evolutionary Developmental Biology (Evo-Devo)
Where can you find more information about the genetic evolution of Darwin's finches?
At the Nature website, specifically the article on the evolution of Darwin's finches.
p.54
Hox Genes and Body Plan Development
What do Hox genes regulate?
The transcription of other genes involved in development.
p.43
Cellular Diversity and Developmental Decisions
What does positional information tell a cell?
Where it is with respect to the animal's body axes.
p.56
Hox Genes and Body Plan Development
What is Pax6/eyeless associated with?
It is a highly conserved transcription factor important for eye development.
p.27
Protostome vs. Deuterostome Development
What are morphogenetic determinants?
Components that influence the development of specific cell fates.
p.6
Fertilization and Gamete Interaction
What role do egg-recognition proteins play in fertilization?
They bind to species-specific sperm receptors on the vitelline envelope to ensure recognition of the same species.
p.21
Gastrulation and Germ Layer Formation
What are the three germ layers formed after cleavage?
Ectoderm (outer layer), Mesoderm (middle layer), Endoderm (inner layer).
p.51
Evolutionary Developmental Biology (Evo-Devo)
What is the big question regarding diversity in species?
How do we get diversity between species versus variation within a species?
p.55
Hox Genes and Body Plan Development
What are homeotic selector genes responsible for?
Controlling the patterning of body structures.
p.22
Gastrulation and Germ Layer Formation
What does gastrulation in a sea urchin produce?
An embryo with a primitive gut (archenteron) and three germ layers.
p.15
Cleavage and Early Embryonic Development
Does cell growth occur during cleavage?
No, only subdivision occurs until cells reach regular somatic cell size.
p.50
Evolutionary Developmental Biology (Evo-Devo)
What is an example of species that can show variation?
Different species of bats.
p.41
Cellular Diversity and Developmental Decisions
How is development organized?
As a sequence of local patterns where one step is a subunit of another, with each step being a necessary preliminary for the next.
p.9
Fertilization and Gamete Interaction
What occurs during the cortical reaction in mammals?
Enzymes are released that modify the egg surface to prevent any sperm from binding.
p.7
Fertilization and Gamete Interaction
What happens to the sperm head during fertilization?
It is drawn in and fuses with the egg plasma membrane.
p.53
Hox Genes and Body Plan Development
What are MADS-box genes?
A similar group of genes in plants that influence plant development.
p.53
Hox Genes and Body Plan Development
What is the significance of Hox genes?
They are essential metazoan genes that determine the identity of embryonic regions along the anterior-posterior axis.
p.32
Cellular Diversity and Developmental Decisions
What is induction in developmental biology?
The capacity of some cells to evoke a developmental response like shape and fate in other cells.
p.32
Cellular Diversity and Developmental Decisions
How can induction be influenced?
Induction can be influenced reciprocally.
p.2
Cellular Diversity and Developmental Decisions
What leads to the development of diverse cell types in the animal body?
Conditions created in preceding stages.
p.46
Evolutionary Developmental Biology (Evo-Devo)
How are novel phenotypes introduced into a population?
Through developmental processes.
p.18
Gastrulation and Germ Layer Formation
What does the ectoderm form?
The outer layer of the gastrula, including outer surfaces and neural tissue.
p.19
Cleavage and Early Embryonic Development
What is a complete gut?
A pathway from the mouth to the anus.
p.42
Hox Genes and Body Plan Development
What do Hox genes control in embryonic development?
The subdivision of embryos into regions of different developmental fates along the anteroposterior axis.
p.69
Evolutionary Developmental Biology (Evo-Devo)
Why is there variability in bill sizes within the same species?
Due to changes during development.
p.57
Hox Genes and Body Plan Development
What role do transcription factors play in the expression of HOX genes?
They drive the spatial pattern of HOX gene expression.
p.57
Hox Genes and Body Plan Development
What do HOX genes trigger in developmental pathways?
Cascades of developmental gene pathways via transcription factors.
p.6
Fertilization and Gamete Interaction
What challenge do small sperm face in the ocean?
Fertilization is difficult due to the vastness of the ocean.
p.6
Fertilization and Gamete Interaction
What do many eggs release to attract sperm?
A chemotactic molecule to attract sperm of the same species.
p.6
Fertilization and Gamete Interaction
What is a universal property of animals regarding fertilization?
Species-specific recognition proteins.
p.12
Fertilization and Gamete Interaction
What happens to the sperm head during fertilization?
The sperm head is drawn in and fuses with the egg plasma membrane.
p.58
Evolutionary Developmental Biology (Evo-Devo)
What does the induction of legs or eyes by a mutation in one gene suggest?
It suggests that these and other organs can develop as modules.
p.31
Cellular Diversity and Developmental Decisions
What role do cytoplasmic determinants play in the egg cell?
They are important in establishing the body axes.
p.5
Fertilization and Gamete Interaction
What is the primary focus of research on fertilization and activation?
Much of the knowledge is based on marine invertebrates, especially sea urchins and fishes.
p.51
Evolutionary Developmental Biology (Evo-Devo)
What is the primary mechanism that leads to diversity within species?
Natural Selection acting on variation within a population.
p.48
Evolutionary Developmental Biology (Evo-Devo)
What is evolutionary developmental biology (Evo-Devo)?
It is the study of how evolution leads to differences in organisms due to changes in genetic control of development.
p.14
Fertilization and Gamete Interaction
What does the male pronucleus do after formation?
It migrates inward to contact the female pronucleus.
p.8
Fertilization and Gamete Interaction
What is the result of the osmotic gradient created during the slow block?
Water rushes into the space, elevating the envelope and lifting away all bound sperm except the one that fused with the egg.
p.8
Fertilization and Gamete Interaction
What is formed as a result of the slow block reaction?
The fertilization membrane.
p.1
Cleavage and Early Embryonic Development
What initiates the process of development?
The mitotic division of a fertilized egg to produce a multi-celled embryo.
p.41
Cellular Diversity and Developmental Decisions
What is morphogenesis?
The process by which an animal takes shape and differentiated cells end up in their appropriate locations.
p.60
Evolutionary Developmental Biology (Evo-Devo)
How do BMP4 and CaM affect bill shape?
They influence the size and shape of the bills.
p.54
Hox Genes and Body Plan Development
What is the pattern of HOX gene expression?
Highly conserved anterior-posterior patterns.
p.24
Cellular Diversity and Developmental Decisions
What can happen to a blastomere isolated early in cleavage in Deuterostomes?
It can form a whole individual.
p.62
Evolutionary Developmental Biology (Evo-Devo)
How do large-beaked birds benefit in their feeding habits?
They can crack big, hard seeds.
p.13
Fertilization and Gamete Interaction
What is the 'fast block' in sea urchin fertilization?
An electrical potential change that rapidly spreads across the membrane to prevent the entry of other sperm.
p.57
Evolutionary Developmental Biology (Evo-Devo)
How does natural variation within a species lead to natural selection?
Natural variation provides the raw material on which natural selection can act, favoring traits that enhance survival and reproduction.
p.68
Cellular Diversity and Developmental Decisions
Where is Isla Daphne Major located?
In the Galápagos Islands.
p.59
Hox Genes and Body Plan Development
What is an example of how Hox genes can influence development in arthropods?
Hox gene changes can alter the number of legs.
p.8
Fertilization and Gamete Interaction
What is the slow block in sea urchin fertilization?
A cortical reaction that occurs after the fast block event.
p.55
Hox Genes and Body Plan Development
How does the expression of Hox genes occur?
In an anterior-posterior pattern.
p.1
Cellular Diversity and Developmental Decisions
What does development represent in an individual?
A series of progressive changes from beginning to maturity.
p.22
Gastrulation and Germ Layer Formation
What is the blastopore?
The open end of the gut that becomes the anus in deuterostomes.
p.33
Cellular Diversity and Developmental Decisions
What is induction in the context of embryonic development?
Induction is the capacity of some cells to cause other cells to develop in a certain way.
p.33
Cellular Diversity and Developmental Decisions
What role does the dorsal lip of the blastopore play in development?
It induces neural development.
p.29
Protostome vs. Deuterostome Development
What are the two clades of protostomes mentioned?
Ecdysozoan protostomes and other taxa that molt their exoskeletons.
p.53
Hox Genes and Body Plan Development
What is the Homeobox?
A highly conserved amino acid coding sequence shared among Hox genes that binds DNA.
p.53
Hox Genes and Body Plan Development
What role do Hox genes play in development?
They regulate the transcription of other genes involved in gene cascades during development.
p.35
Cleavage and Early Embryonic Development
In which organisms are isolecithal eggs found?
Echinoderms, tunicates, cephalochordates, molluscs, and mammals.
p.61
Evolutionary Developmental Biology (Evo-Devo)
How do switches affect gene expression during development?
They turn genes on and off during different phases of development.
p.46
Gastrulation and Germ Layer Formation
What role does cell migration play in gastrulation?
It causes tissue invagination through changes in cell shape and migration.
p.2
Cellular Diversity and Developmental Decisions
What are the two basic processes responsible for progressive subdivision of cells?
Cytoplasmic specification and induction.
p.11
Cleavage and Early Embryonic Development
What are actins and tubulins used for in the zygote?
They are needed for cell division.
p.20
Gastrulation and Germ Layer Formation
What is a coelom?
A coelom is a body cavity surrounded by mesoderm.
p.11
Cleavage and Early Embryonic Development
What happens to the original cytoplasm during cleavage?
It is continuously divided into smaller units.
p.40
Cleavage and Early Embryonic Development
Where is the blastocoel located in frogs?
In the animal hemisphere.
p.19
Cleavage and Early Embryonic Development
How is the second opening of the gut formed?
By merging of the archenteron tube with the ectoderm.
p.40
Cleavage and Early Embryonic Development
What is the characteristic of meroblastic cleavage?
Incomplete division of the egg.
p.56
Hox Genes and Body Plan Development
What happens in a mouse lacking Pax6?
It results in developmental defects, particularly in eye formation.
p.58
Evolutionary Developmental Biology (Evo-Devo)
What is a key concept in Evolutionary Developmental Biology (Evo-Devo)?
Evolution could proceed by relatively few mutations in a few developmental genes instead of gradual accumulation of numerous small mutations.
p.21
Gastrulation and Germ Layer Formation
From which layers do all other structures derive?
From one of the three germ layers.
p.5
Fertilization and Gamete Interaction
Which vertebrates have been studied for fertilization?
Mice, rabbits, and hamsters.
p.10
Fertilization and Gamete Interaction
What is formed when the male and female pronuclei fuse?
A diploid zygote nucleus.
p.41
Cellular Diversity and Developmental Decisions
What is cell differentiation?
The specialization of cells in their structure and function.
p.30
Hox Genes and Body Plan Development
What are cytoplasmic determinants?
Substances unevenly distributed in the egg that lead to differences in cell fate.
p.15
Cleavage and Early Embryonic Development
What happens to the original cytoplasm during cleavage?
It is continuously divided into smaller units.
p.9
Fertilization and Gamete Interaction
How is the fertilization membrane formed?
It is formed when one cortical granule enzyme causes the vitelline envelope to harden.
p.9
Fertilization and Gamete Interaction
Do mammals have a fertilization membrane?
No, mammals do not have a fertilization membrane.
p.37
Cleavage and Early Embryonic Development
What type of cleavage do telolecithal eggs undergo?
Meroblastic or incomplete cleavage.
p.64
Evolutionary Developmental Biology (Evo-Devo)
What significant event is referred to as 'The BIG Drought'?
The drought that occurred from 1976 to 1977.
p.37
Cleavage and Early Embryonic Development
In which organisms are telolecithal eggs commonly found?
Birds, reptiles, most fishes, and a few amphibians.
p.34
Gastrulation and Germ Layer Formation
What effect did the dorsal blastopore lip have on the host ectoderm?
It induced the host ectoderm to form a neural tube.
p.44
Cellular Diversity and Developmental Decisions
How does morphogenesis differ between plants and animals?
In animals, it involves the movement of cells, while in plants it does not.
p.66
Evolutionary Developmental Biology (Evo-Devo)
What is the significance of bill size in G. fortis?
It is a trait that influenced survival during drought conditions.
p.36
Cellular Diversity and Developmental Decisions
How do eggs cleave in the yolk-rich vegetal pole of mesolecithal eggs?
Slowly and following a radial direction.
p.25
Protostome vs. Deuterostome Development
What is enterocoely?
The process where the coelom forms as outpocketing of the gut.
p.28
Protostome vs. Deuterostome Development
What are pseudocoelomates?
Organisms with a body cavity between mesoderm and endoderm.
p.28
Protostome vs. Deuterostome Development
What are acoelomates?
Organisms with no body cavity other than the gut.
p.28
Protostome vs. Deuterostome Development
What is a trochophore larva?
A larval form that features all four protostome characteristics.
p.3
Oocyte Maturation and Egg Activation
When does sperm typically enter the primary oocyte in many organisms?
Before meiosis is completed.
p.3
Fertilization and Gamete Interaction
In some species, what role does sperm play in egg activation?
Sperm is required for egg activation but contributes no genetic material.
p.45
Cellular Diversity and Developmental Decisions
Which structures affect the formation of the neural tube?
Microtubules and microfilaments.
p.6
Fertilization and Gamete Interaction
What is the vitelline envelope?
A thin membrane above the egg plasma membrane.
p.14
Fertilization and Gamete Interaction
What happens to the sperm nuclear envelope during fertilization?
It breaks apart to allow chromatin to expand.
p.55
Hox Genes and Body Plan Development
What do Hox genes control in animals?
The morphology of segments.
p.24
Protostome vs. Deuterostome Development
What organisms are included in the group of Deuterostomes?
Echinoderms (like sea urchins and sea stars) and chordates.
p.10
Fertilization and Gamete Interaction
What is the significance of the fusion of sperm and egg nuclei?
It forms a diploid zygote nucleus, which is crucial for development.
p.52
Evolutionary Developmental Biology (Evo-Devo)
What does evolutionary developmental biology link together?
Genetics with evolution through the agencies of development.
p.30
Hox Genes and Body Plan Development
What role does the position of cells in the early embryo play?
It results in differences in cell fate.
p.64
Evolutionary Developmental Biology (Evo-Devo)
Can changes during development create diverse variation within a species?
Yes, these changes can provide the variation that natural selection acts upon.
p.49
Evolutionary Developmental Biology (Evo-Devo)
What is the big question in the context of natural selection?
How do we get phenotypic variation?
p.29
Cellular Diversity and Developmental Decisions
How do different genes affect embryonic development?
Different genes will be expressed in different cells.
p.43
Cellular Diversity and Developmental Decisions
What do the wings and legs of chicks begin as?
Bumps of tissue called limb buds.
p.23
Protostome vs. Deuterostome Development
What are the two major groups of triploblastic animals?
Protostomes and Deuterostomes.
p.32
Cellular Diversity and Developmental Decisions
How do inducers work in the process of induction?
Inducers work with surface proteins of adjacent cells or by diffusion of growth and differentiating molecules.
p.2
Cellular Diversity and Developmental Decisions
What happens as interactions between cells become increasingly restrictive?
Each new stage limits developmental fate.
p.46
Evolutionary Developmental Biology (Evo-Devo)
How might natural selection act on novel phenotypes?
By favoring traits that enhance survival and reproduction.
p.20
Gastrulation and Germ Layer Formation
What is the mesoderm and how does it form?
The mesoderm is the third germ layer that forms between the endoderm and ectoderm, and it forms through the proliferation of cells near the blastopore or by pushing the archenteron wall into the space between the archenteron and the outer body wall.
p.16
Cleavage and Early Embryonic Development
What characterizes the animal pole of the embryo?
It contains mostly cytoplasm.
p.63
Evolutionary Developmental Biology (Evo-Devo)
What does inheritance refer to in the context of natural selection?
Individuals pass on at least some of their traits to their offspring.
p.38
Cleavage and Early Embryonic Development
What is the animal pole?
The pole of the egg with the least yolk.
p.3
Oocyte Maturation and Egg Activation
What occurs during meiosis in oocytes?
Two chromosomal divisions occur, forming four haploid nuclei.
p.16
Cleavage and Early Embryonic Development
What factors can affect cleavage?
Quantity and distribution of yolk, and genes controlling symmetry.
p.4
Oocyte Maturation and Egg Activation
When do most preparations in the egg occur in mammals?
During the prolonged prophase I.
p.39
Cellular Diversity and Developmental Decisions
What are the four types of yolk distribution in animal eggs?
Isolecithal, Mesolecithal, Telolecithal, Centrolecithal.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What must individuals within a population do for natural selection to occur?
Individuals must vary phenotypically.
p.31
Cellular Diversity and Developmental Decisions
How does cellular potency change during embryonic development?
The potency of cells becomes progressively more limited.
p.5
Oocyte Maturation and Egg Activation
What is the process of maturation for the primary oocyte?
It involves specific developmental stages leading to oocyte readiness for fertilization.
p.10
Fertilization and Gamete Interaction
What happens to the sperm after the membranes of sperm and egg fuse?
The sperm loses its flagellum and its nuclear envelope breaks apart.
p.15
Cleavage and Early Embryonic Development
What occurs in the zygote to prepare for cleavage?
Several cytoplasmic changes.
p.52
Evolutionary Developmental Biology (Evo-Devo)
What did Thomas Huxley advise Darwin in 1857 regarding differences between organisms?
That differences result not so much from the development of new parts but from the modification of existing parts common to divergent types.
p.9
Fertilization and Gamete Interaction
What is the function of the fertilization membrane?
It acts as a permanent physical barrier to prevent polyspermy by hardening the vitelline envelope.
p.41
Cellular Diversity and Developmental Decisions
Is there a master control panel directing development?
No, there is no 'hard-wired' master control panel directing development.
p.33
Cellular Diversity and Developmental Decisions
What is referred to as the primary organizer in embryonic development?
The dorsal lip of the blastopore.
p.62
Evolutionary Developmental Biology (Evo-Devo)
What limitation do small-beaked birds face?
They cannot crack large, hard seeds.
p.62
Evolutionary Developmental Biology (Evo-Devo)
What species is being studied for rapid evolution of bill size?
Medium ground finches (Geospiza fortis).
p.53
Hox Genes and Body Plan Development
What is a transcription factor?
A protein that affects the transcription of an associated gene by interacting with a regulatory DNA sequence.
p.7
Fertilization and Gamete Interaction
What mechanism does the sea urchin use to prevent polyspermy?
A 'fast block' occurs, which is an electrical potential change that spreads across the membrane.
p.7
Fertilization and Gamete Interaction
What changes occur on the egg surface after the first sperm enters?
Numerous changes block the entrance of any additional sperm.
p.66
Evolutionary Developmental Biology (Evo-Devo)
What was the bill size of G. fortis offspring born in 1976?
Average bill size was 11.3 mm.
p.66
Evolutionary Developmental Biology (Evo-Devo)
What does the data suggest about the survival of G. fortis during the drought?
There was differential survival based on bill size.
p.36
Cellular Diversity and Developmental Decisions
What type of cleavage do mesolecithal eggs undergo?
Holoblastic (complete cleavage).
p.36
Cellular Diversity and Developmental Decisions
How does the cleavage furrow behave in mesolecithal eggs?
It extends completely through the egg.
p.38
Cleavage and Early Embryonic Development
What is superficial cleavage?
Cleavage that restricts division to the cytoplasmic rim of the egg.
p.38
Cleavage and Early Embryonic Development
In which organisms does centrolecithal egg cleavage occur?
In arthropods like insects.
p.18
Gastrulation and Germ Layer Formation
What is the role of the endoderm?
It lines the embryonic digestive tract.
p.20
Gastrulation and Germ Layer Formation
What are the two types of coelomic cavity formation?
Schizocoely, which forms by splitting mesoderm, and enterocoely, which forms by out-pocketing of mesoderm from the endoderm.
p.19
Cleavage and Early Embryonic Development
What do the ectoderm and endoderm layers form?
The endodermal tube or the gut.
p.63
Evolutionary Developmental Biology (Evo-Devo)
What factors contribute to the size difference in the bills of Geospiza fortis?
How much and when genes are turned off and on.
p.4
Oocyte Maturation and Egg Activation
What are morphogenetic determinants responsible for during post-fertilization development?
They direct the activation and repression of specific genes.
p.40
Cleavage and Early Embryonic Development
In which species does meroblastic cleavage occur?
Species with yolk-rich eggs, such as reptiles and birds.
p.39
Cellular Diversity and Developmental Decisions
What defines mesolecithal eggs?
A moderate amount of yolk concentrated at the vegetal pole.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What does the slope of the bill size graph (1976=1978) indicate?
It indicates a heritable trait with a slope of approximately 0.7.
p.15
Cleavage and Early Embryonic Development
What happens during cleavage in the embryo?
The embryo divides repeatedly, with both nuclei and cytoplasm dividing completely.
p.26
Protostome vs. Deuterostome Development
Which organisms are included in protostomes?
Flatworms, annelids, and molluscs.
p.49
Evolutionary Developmental Biology (Evo-Devo)
What is natural selection?
A mechanism for evolution that acts on phenotypic variation.
p.49
Evolutionary Developmental Biology (Evo-Devo)
What does Evo-Devo study?
The development processes in organisms to understand evolutionary relationships and the emergence of novel phenotypes.
p.49
Evolutionary Developmental Biology (Evo-Devo)
Why is phenotypic variation important for natural selection?
Natural selection can only act on populations that exhibit phenotypic variation.
p.49
Evolutionary Developmental Biology (Evo-Devo)
What are the two main focuses of Evo-Devo?
1) Understanding evolutionary relationships between organisms 2) How changes in development create diverse variation for natural selection.
p.29
Cellular Diversity and Developmental Decisions
What determines an organism's development?
The genome of the zygote and differences that arise between early embryonic cells.
p.37
Cleavage and Early Embryonic Development
What is a characteristic of cleavage in telolecithal eggs?
Cleavage furrow does not cut through the heavy yolk.
p.43
Cellular Diversity and Developmental Decisions
How does positional information affect a cell's descendants?
It determines how they respond to future molecular signals.
p.23
Gastrulation and Germ Layer Formation
What complicates gastrulation in frogs?
Yolk-laden cells in the vegetal hemisphere and a blastula wall that is more than one cell thick.
p.36
Cellular Diversity and Developmental Decisions
What type of yolk disposition do mesolecithal eggs have?
Moderate vegetal yolk disposition.
p.2
Fertilization and Gamete Interaction
What is the initial event in sexual reproduction?
Fertilization, the union of male and female gametes.
p.63
Evolutionary Developmental Biology (Evo-Devo)
What is the second condition for natural selection?
Individuals within a population must vary phenotypically.
p.18
Gastrulation and Germ Layer Formation
What does the mesoderm partly fill?
The space between the endoderm and ectoderm, forming muscles and the reproductive system.
p.28
Protostome vs. Deuterostome Development
What do lophotrochozoan protostomes include?
Annelid worms, molluscs, and some small phyla.
p.40
Cleavage and Early Embryonic Development
How do animal pole blastomeres compare in size to vegetal pole blastomeres in frogs?
Animal pole blastomeres are smaller.
p.3
Oocyte Maturation and Egg Activation
In some taxa, when does sperm enter the oocyte?
After the first or second meiotic divisions.
p.3
Fertilization and Gamete Interaction
What is artificial parthenogenesis?
The process where eggs are artificially induced to initiate development without sperm.
p.39
Cellular Diversity and Developmental Decisions
What characterizes isolecithal eggs?
Very little yolk with even distribution.
p.17
Cleavage and Early Embryonic Development
What is a blastula?
A hollow ball of cells with a fluid-filled cavity called the blastocoel.
p.24
Cellular Diversity and Developmental Decisions
What is meant by regulative development in Deuterostomes?
The fate of a cell depends on its interactions with neighbors, not on the cytoplasm it contains.
p.62
Evolutionary Developmental Biology (Evo-Devo)
What is the primary factor influencing bill size in medium ground finches?
Natural selection based on seed size.
p.50
Evolutionary Developmental Biology (Evo-Devo)
What is the primary question regarding species variation?
How do we get this variation or diversity between species?
p.7
Fertilization and Gamete Interaction
What is polyspermy?
The entry of more than one sperm to one egg, which is harmful to normal development.
p.54
Hox Genes and Body Plan Development
Why are homeotic genes important?
They produce complementary effects necessary for the ordered development of an organism.
p.32
Cellular Diversity and Developmental Decisions
What is conditional specification in development?
The fate of a cell is not fixed until it receives positional information from neighboring cells.
p.38
Cleavage and Early Embryonic Development
Does the cleavage furrow cut through the yolk in centrolecithal eggs?
No, it does not cut through the yolk at all.
p.19
Cleavage and Early Embryonic Development
Which animals retain a blind gut?
Some invertebrates like sea anemones.
p.2
Fertilization and Gamete Interaction
What is the size difference between the egg and sperm?
The egg is normally 200 times larger than somatic cells, while sperm is only 1/50 the size.
p.40
Cleavage and Early Embryonic Development
What is the cleavage pattern in frogs relative to?
The animal and vegetal poles of the zygote.
p.16
Cleavage and Early Embryonic Development
What is a morula?
A solid ball of cells formed after the first 5-7 divisions.
p.4
Oocyte Maturation and Egg Activation
What components are found in the cytoplasm of the egg during oogenesis?
mRNA, ribosomes, tRNA, and other elements for protein synthesis.
p.39
Cellular Diversity and Developmental Decisions
How does the polarity of the egg influence body axis development in frogs?
It determines the anterior-posterior axis before fertilization.
p.39
Cleavage and Early Embryonic Development
What happens during the first cleavage division in frog embryos?
It bisects the gray crescent.
p.67
Evolutionary Developmental Biology (Evo-Devo)
How do different traits affect survival or reproductive success?
Individuals with different traits differ in their survival or reproductive success during the struggle for existence.
p.39
Cellular Diversity and Developmental Decisions
What distinguishes centrolecithal eggs?
Lots of yolk that is centrally located.
p.17
Gastrulation and Germ Layer Formation
What is a primitive gut?
The structure present in a gastrula formed during gastrulation.
p.29
Protostome vs. Deuterostome Development
Do many ecdysozoans show spiral cleavage?
No, many do not show spiral cleavage.
p.64
Evolutionary Developmental Biology (Evo-Devo)
What is the difference between variation within a species and variation between species?
Variation within a species refers to differences among individuals of the same species, while variation between species refers to differences among distinct species.
p.35
Cleavage and Early Embryonic Development
How does the cleavage furrow behave in isolecithal eggs?
It extends completely through the egg.
p.64
Evolutionary Developmental Biology (Evo-Devo)
What was the rainfall measurement in millimeters during the years 1976 and 1977?
The data indicates a significant drop in rainfall during these years, leading to drought conditions.
p.44
Cellular Diversity and Developmental Decisions
What is morphogenesis?
A major aspect of development involving the movement of cells, primarily in animals.
p.66
Evolutionary Developmental Biology (Evo-Devo)
What was the bill size of G. fortis offspring born in 1978 compared to 1976?
>4% increase in offspring bill size from 1976 to 1978.
p.61
Evolutionary Developmental Biology (Evo-Devo)
How might we observe changes in frequencies of bill sizes?
Through the action of natural selection over time.
p.46
Evolutionary Developmental Biology (Evo-Devo)
What is evolutionary development (Evo-Devo)?
A field that studies how evolutionary processes influence development.
p.28
Protostome vs. Deuterostome Development
What forms before the coelom in protostome development?
A mesodermal band of tissue.
p.2
Fertilization and Gamete Interaction
What does fertilization restore in the nucleus?
The diploid number of chromosomes.
p.38
Cleavage and Early Embryonic Development
What is the vegetal pole?
The pole of the egg with the most yolk.
p.19
Cleavage and Early Embryonic Development
How is a complete gut formed?
Through the inward movement of the archenteron until it reaches the ectodermal wall of the gastrula.
p.4
Oocyte Maturation and Egg Activation
What happens to an egg during oogenesis?
It grows in size by accumulating yolk.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What is necessary for individuals to form the next generation?
Individuals must reproduce.
p.4
Oocyte Maturation and Egg Activation
What happens after meiosis resumes in oocyte maturation?
The egg is ready to fuse its nucleus with the sperm nucleus.
p.40
Cleavage and Early Embryonic Development
What is the blastoderm in birds?
A cap of cells on top of the yolk.
p.67
Evolutionary Developmental Biology (Evo-Devo)
How does bill size relate to heritability?
Small-billed parents breed small-billed offspring, and large-billed parents breed large-billed offspring.
p.54
Hox Genes and Body Plan Development
What is the role of homeotic proteins?
They can activate one gene while repressing another, ensuring ordered development.
p.54
Hox Genes and Body Plan Development
What is a homeobox?
A sequence of DNA within homeotic genes that encodes a segment of 60 amino acids.
p.34
Gastrulation and Germ Layer Formation
What was the main focus of the Spemann-Mangold experiment?
Transplanting a piece of dorsal blastopore lip from a salamander gastrula.
p.35
Cleavage and Early Embryonic Development
What are the possible directions of division in isolecithal eggs?
Radial, spiral, or rotational.
p.61
Evolutionary Developmental Biology (Evo-Devo)
What factors influence the shape of a bill?
How much each gene is expressed and when each gene is expressed.
p.43
Cellular Diversity and Developmental Decisions
What do embryonic cells within a limb bud respond to?
Positional information indicating location along three axes.
p.23
Protostome vs. Deuterostome Development
What are the two types of coelom formation in triploblastic animals?
Schizocoelous and enterocoelous coelom formation.
p.25
Protostome vs. Deuterostome Development
What happens to the blastopore in deuterostome development?
It becomes the anus, and the mouth develops as the second opening.
p.11
Cleavage and Early Embryonic Development
What processes are initiated after the removal of metabolic inhibitors?
A burst of DNA and protein synthesis occurs using mRNA stored in the egg cytoplasm.
p.19
Cleavage and Early Embryonic Development
What is a blind or incomplete gut?
When the embryonic gut opens only into the blastopore.
p.20
Gastrulation and Germ Layer Formation
What distinguishes diploblastic animals from triploblastic animals?
Diploblastic animals have two germ layers, while triploblastic animals have three germ layers.
p.16
Cleavage and Early Embryonic Development
What is cleavage in embryonic development?
A series of rapid cell divisions following fertilization.
p.63
Evolutionary Developmental Biology (Evo-Devo)
How do individuals with different traits affect natural selection?
They differ in their survival or reproductive success.
p.63
Evolutionary Developmental Biology (Evo-Devo)
What is the size difference between the two medium ground finches (Geospiza fortis)?
One bill is 25% bigger than the other.
p.3
Oocyte Maturation and Egg Activation
What happens to the nuclei formed during oocyte meiosis?
One nucleus stays within the oocyte while three move outside to form three polar bodies.
p.18
Gastrulation and Germ Layer Formation
What layers does the gastrula consist of?
An outer layer of ectoderm and an inner layer of endoderm.
p.3
Fertilization and Gamete Interaction
Is sperm always required for development?
No, some species can initiate development without sperm through artificial parthenogenesis.
p.3
Fertilization and Gamete Interaction
What is natural parthenogenesis?
A phenomenon where some species have eggs that develop normally in the absence of sperm.
p.39
Cellular Diversity and Developmental Decisions
What is the characteristic of telolecithal eggs?
Lots of yolk at the vegetal pole.
p.44
Cellular Diversity and Developmental Decisions
What is the apical ectodermal ridge (AER)?
A thickened area of ectoderm at the tip of the limb bud.
p.23
Gastrulation and Germ Layer Formation
What is the result of gastrulation in frogs?
An embryo with a gut and three germ layers.
p.53
Hox Genes and Body Plan Development
What is the function of the Homeobox DNA sequence?
It is involved in the regulation of patterns of anatomical development.
p.23
Protostome vs. Deuterostome Development
How are protostomes and deuterostomes differentiated?
By spiral vs. radial cleavage, regulative vs. mosaic cleavage, and whether the blastopore becomes the mouth or anus.
p.25
Protostome vs. Deuterostome Development
What is a coelom?
A body cavity completely surrounded by mesoderm.
p.63
Evolutionary Developmental Biology (Evo-Devo)
What is the first condition for natural selection?
Individuals must reproduce to form the next generation and produce more than what will survive.
p.38
Cleavage and Early Embryonic Development
What defines the polarity of eggs and zygotes in many animals?
The distribution of yolk.
p.11
Cleavage and Early Embryonic Development
What are blastomeres?
Small maneuverable cells formed during cleavage.
p.16
Cleavage and Early Embryonic Development
What is a blastomere?
Each cell formed during cleavage.
p.18
Gastrulation and Germ Layer Formation
What is formed during gastrulation that creates a new internal cavity?
The archenteron or gastrocoel.
p.4
Oocyte Maturation and Egg Activation
What is the germinal vesicle?
The egg nucleus that grows in size, bloated with RNA.
p.4
Oocyte Maturation and Egg Activation
What do the resources in a mature oocyte support?
The nutritional requirements of the embryo after fertilization and direct its development through cleavage.
p.44
Cellular Diversity and Developmental Decisions
What is the function of the zone of polarizing activity (ZPA)?
It organizes limb development and is located underneath the ectoderm at the posterior side of the bud.
p.61
Evolutionary Developmental Biology (Evo-Devo)
What role does natural selection play in bill size variation?
Natural selection acts on the different bill sizes, influencing their frequencies.
p.46
Cellular Diversity and Developmental Decisions
What is cell migration?
The active movement of cells from one place to another.
p.11
Cleavage and Early Embryonic Development
What happens to the egg after fertilization?
Inhibitors of metabolism are removed, allowing the egg to initiate metabolism.
p.25
Protostome vs. Deuterostome Development
How do mesoderm and coelom form in deuterostomes?
They form simultaneously.
p.2
Fertilization and Gamete Interaction
What does fertilization provide for?
Recombination of paternal and maternal genes.
p.11
Cleavage and Early Embryonic Development
What occurs during cleavage in terms of cell division?
Both nuclei and cytoplasm divide completely, leading to multicellular formation.
p.19
Cleavage and Early Embryonic Development
What happens to the blastopore in some organisms?
It becomes the mouth in some creatures and the anus in others.
p.11
Cleavage and Early Embryonic Development
Does cell growth occur during cleavage?
No, only subdivision occurs until cells reach regular somatic cell size.
p.16
Cleavage and Early Embryonic Development
What occurs during cleavage in terms of growth?
Very little growth occurs.
p.39
Cellular Diversity and Developmental Decisions
What is the gray crescent in frog development?
A region of lighter-colored cytoplasm that marks the dorsal side.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What advantage do large-billed birds have?
They survive and reproduce better when large seeds prevail.
p.20
Gastrulation and Germ Layer Formation
How are schizocoely and enterocoely functionally related?
Both types of coelomic cavities are functionally equivalent.
p.28
Protostome vs. Deuterostome Development
What is a lophophore?
A horseshoe-shaped feeding structure.
p.20
Gastrulation and Germ Layer Formation
What is the significance of coelom formation in evolutionary biology?
Coelom formation is an inherited character and can be used as evidence of shared ancestry.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What is the concept of inheritance in relation to traits?
Individuals pass on at least some of their traits to their offspring.
p.4
Oocyte Maturation and Egg Activation
What characterizes a mature oocyte?
It has become a highly structured system with abundant resources.
p.67
Evolutionary Developmental Biology (Evo-Devo)
What advantage do small-billed birds have?
They are more efficient and leave more offspring when small seeds are relatively common.
