BIOLOGY 112: EXAM 3 PREP--Lecture 1

Early Gastrulation in humans

1) Blastocyst reaches uterus. 2) Blastocyst implants (7 days after fertilization). 3) Extraembryonic membranes start to form (10-11 days) and gastrulation begins (13 days). Gastrulation has produced a three-layer embryo with four extraembryonic membranes; the amnion, chorion, yolk sac, and allantois.

What is sexually immature and morphologically distinct from the adult and eventually undergoes metamorphosis to become a juvenile?

A larva. *Differentiation of the body—the Somatic cell line. Most animals have at least one juvenile and/or larval stage prior to adult. Regulated by hormones and microRNAs.

What is a movement in which a sheet of cells undergoes rearrangement to form a longer and narrower shape?

A morphogenetic movement *Cells elongate and wedge between each other to form fewer columns of cells—driven by cytoskeleton.

The nerve cord/ neural tube of a chordate embryo develops from a plate of *blank* that rolls into a tube dorsal to the notochord.

A plate of ectoderm

What is an organ that is a net consumer or storer of sugar, such as a tuber or bulb. (Concept 36.5)

A sugar sink

What is an organ that is the net producer of sugar, such as mature leaves? (Concept 36.5)

A sugar source

Chiroptera: Birds.

Adapted for flight; broad skinfold that extends from elongated fingers to body and legs; carnivorous and herbivorous.

Concept 36.1

Adaptions for acquiring resources were key steps in the evolution of vascular plants.

Concept 47.2 Morphogenesis in animals involves specific changes in cell shape, position and survival

After cleavage, the rate of cell division slows and the normal cell cycle is restored. Morphogenesis, the cell and tissue based process by which the animal body takes shape, involves: gastrulation, the movement of cells from the blastula surface to the interior of the embryo. Organogenesis, the formation of organs.

After gastrulation, dorsal mesoderm forms *blank*, dorsal ectoderm forms neural plate. Two ridges form: the *blank*.

After gastrulation, dorsal mesoderm forms *notochord*, dorsal ectoderm forms neural plate. Two ridges form: the *neural folds*.

Homeobox gene products contain a *blank* domain that binds to DNA and functions as a transcription regulator.

An identical or very similar nucleotide sequence has been discovered in the homeotic genes of bother vertebrates and invertebrates. Homeobox gene products contain a *peptide* domain that binds to DNA and functions as a transcription regulator. Related homeobox, regulatory sequences have been found in regulatory genes of yeasts, plants (knotted and Knox genes), and even prokaryotes—not necessarily homeotic.

Sirenia: Manatees and dugongs.

Aquatic, finlike forelimbs and no hind limbs; herbivorous.

Cetaceans: whales, dolphins, porpoises.

Aquatic; streamlined body; paddle-like forelimbs and no hind limbs; thick layer of insulating blubber; carnivorous.

Maternal effect genes encode cytoplasmic determinants that initially establish the axes of the body of Drosophila. These maternal effect genes are also called *blank* genes because they control orientation of the egg and consequently the fly.

Axis Establishment Maternal effect genes encode cytoplasmic determinants that initially establish the axes of the body of Drosophila. These maternal effect genes are also called *egg-polarity* genes because they control orientation of the egg and consequently the fly.

Cleavage patters in evolution—gateway to large changes in what?

Bilateral morphogenesis.

Derived Characters of Birds

Birds probably descended from small theropods, a group of carnivorous dinosaurs with feathers not initially evolved for flight, but for insulation, camouflage or courtship display. Many characters of modern birds are adaptions that facilitate flight—modification of almost every feathers of reptilian anatomy. The majority adaption is wings with keratin feathers. Other adaptions: a urinary bladder females with only one ovary, small gonads, and loss of teeth. Some clades of birds have lost the ability to fly—ratites (ostriches, emus, etc.), and some rails, ducks, and pigeons.

Cleavage into many smaller cells called what?

Blastomeres.

What is a ball of cells with a fluid-filled cavity called a blastocoel?

Blastula

Cleavage leads to formation of a multicellular, hollow *blank*.

Blastula. The blastula undergoes gastrulation, forming a gastrula with different layer of embryonic tissues.

What two factors affect water potential? (Concept 36.3)

Both solute concentration and pressure affect water potential.

Fate map of the invertebrate—C. elegans

C. elegans have lineage-dependent development. Studies of C. elegans used the ablation (destruction) of single cells to determine the structure that normally arise from each cell. The researchers were able to determine the structures that normally arise from each cell. The researchers were able to determine the lineage of each of the 959 somatic cells in the worm.

What entry triggers cortical granule release? This entry also triggers metabolic changes: increase in respiration and protein synthesis—activates the egg. Fusion of the sperm nuclei with egg nuclei completes fertilization.

Calcium

The waxy *blank* strip of the endodermal wall blocks apoplastic transfer of minerals from the cortex to the vascular cylinder. (Concept 36.3)

Casparian

Concept 32.3: Animals can be characterizes by "body plans"

Categorize animals according to a body plan: the organization of somatic tissue and organ systems. In animals, two different types of symmetry. Radial symmetry, with front, back, left, and right indistinguishable—usually sessile and less active. Bialtera symmetry: two sided symmetry—more active and have central nervous system. Bilaterally symmetrical animals have: A dorsal (top side and ventral (bottom) side—not symmetric along the axis. A right and left side—about which they are symmetrical. Anterior (front and posterior (back) ends—not symmetrical along the axis.

Lagomorpha: Rabbits, hares, picas.

Chisel-like incisors; hind legs longer than forelegs and adapted for running and jumping; herbivorous.

Rodentia: Squirrels, beavers, rats, porcupines, mice.

Chisel-like, continuously growing incision worn down by gnawing; herbivorous.

Concept 34.1: Chordates have a notochord and a dorsal, hollow nerve cord.

Chordates (phylum Chordata) are bilaterian animals that belong to the clade of animals knowns as Deuterostomia. Chordates comprise all vertebrates and two groups of invertebrates, the cephalochordates, the lancelets, and the urochordates, the tunicates. Four key shared derived characters of chordates—some of which only appear at certain times in development. Notochord, Dorsal, hollow nerve cord/neural tube, Pharyngeal slits or clefts, and muscular, post-anal tail.

After a sperm fertilizes an egg, the zygote undergoes rapid cell division called what?

Cleavage

What is the fluid or air-filled space between the digestive tract and outer body wall.

Coelom

Concept 32.9—Grades not Clades

Coelomate, Acoelomate, and psuedocoelomate.

Eutherians (Placental Mammals)

Compared to marsupials, eutherians have a more complex placenta. Young eutherians complete their embryonic development within a uterus joined to the mother by the placenta.

What has evolved from simple photosensitive cells independently many times—in insects, molluscs, vertebrates?

Complex eyes

Concept 18.4 A program of differential gene expression leads to the different cell types in a multicellular organism.

Concept 18.4 A program of differential gene expression leads to the different cell types in a multicellular organism. During development, new cell types arise and are organized successively into tissues, organs, organ systems, and the whole organism. Tissues are groups of similar cells that act as a functional unit. Differential gene expression, whereby are regulated differently in each cell type, orchestrates development. Development in the zygote and form stem cells comes from cell division, cell differentiation, and morphogenesis. Cell differentiation is the process by which cells become specialized in structure and function. The physical processes that give an organism its shape constitute morphogenesis. Development is a stacked deck: Preexisting materials—in eggs or other progenitor cells—set up gene regulation.

Concept 34.5 Amniotes are tetrapods that have a terrestrially adapted egg

Concept 34.5 Amniotes are tetrapods that have a terrestrially adapted egg Land vertebrates form four extraembryonic membranes: the chorion, allantois, amnion, and yolk sac. These provide a life-support system for the further development of the embryo. Reproduction outside of aqueous environments required development of: The shelled egg of birds, other reptiles, and the monotremes and the uterus of marsupial and eutheriam mammals. In both adaptations, embryos are surrounded by fluid in a sac called the amnion. This protects the embryo from desiccation and allows reproduction on dry land. Mammals and reptiles included birds are called amniotes for this reason. The chorion functions in gas exchange. The amnion and chorion enclose the amniotic fluid. The yolk sac encloses the yolk. The allantois disposes of waste products and contributes to gas exchange.

After soil solution enters the roots, the extensive surface area of *blank* cell membranes enhances uptake of water and selected minerals. (Concept 36.3)

Cortical

Crocodilians

Crocodilians (alligators and crocodiles) belong to an archosaur lineage that dates back to the late Triassic—they predate dinosaurs!! Some extinct crocodilians were bigger than most dinosaurs—forty feet long (3-4 car lengths)—and probably ate the dinosaurs.

What are uneven distribution of RNA, proteins, and other substances in the unfertilized egg are maternal substances that influence development called?

Cytoplasmic Determinants *Differential partitioning of cytoplasmic determinants leads to differential gene expression.

Concept 34.6 Mammals are amniotes that have hair and produce milk

Derived Characters of Mammals. Mammary glands, which produce milk. Hair. A high metabolic rate, due to endothermy. A larger brain than other vertebrates of equivalent size. Differentiated teeth. Mammals are synapsids. In the evolution of mammals from early synapsids, two bones that formerly made up the jaw joint were incorporated into the mammalian middle ear.

Concept 34.4 Tetrapod are gnathostomes that have limbs.

Derived characters of tetrapod---accompany land colonization 365 mya: Have four limbs instead of pectoral and pelvic fins. Skeletal modifications: multiple vertebrae in neck, pelvic girdle fused to backbone. Pharyngeal clefts give rise to ears and glands, not gills except in some aquatic species. Fossil evidence for origin: Tiktakklik, a "fishpod" from 375 mya.

Determination irreversibly commits a cell to its final fate. What precedes differentiation?

Determination precedes differentiation. *Example: Myoblasts express a transcription factor protein from the master regulatory gene, MyoD. The myoblast and its progeny are determined to become skeletal muscle cells.

Concept 36.2

Different mechanisms transport substances over short or long distances.

*blank* cells, but not *blank* cells, make tissue-specific proteins. When the MyoD transcription factor starts activating the genes to make muscle-specific proteins, such as skeletal myosin, then cells become differentiated.

Differentiated cells, but not determined cells, make tissue-specific proteins.

Cnidarians and other radially symmetrical animals have only these two layers are called what?

Diploblasts.

What gene suppresses limb formation 100% in Drosophila embryos when expressed in all tissues?

Drosophila Ubx gene *Artemia, brine shrimp, Ubx gene suppresses limb formation on 15% in Drosophila embryos when expressed in all tissues. Further analysis with hybrid genes substituting pieces of Drosophila Ubx into Artemia Ubx and expressing it in Drosophila—change in the nucleotide sequence of one small region of the Ubx gene in the six-legged insect body plan.

Eulipotphla: "Core insectivores": Some moles and some shrews.

Eat mainly insects and other small invertebrates.

Give an example of Deuterostome development

Echinoderms and chordates *eight celled stage, radial and indeterminate Anus develops from blastopore Enterocoelous: folds of archenteron form coelom

In most vertebrates, a more complex, jointed skeleton develops, and the adult retains only remnants of what remain?

Embryonic notochord.

Water and minerals in the apoplast must cross the plama membrane of which cell to enter the vascular cylinder? (Concept 36.3)

Endodermal

Ectoderm (outer layer of embryo)

Epidermis of skin and it dervatives (including sweat glands, hair follicles) Nervous and sensory systems. Pituitary glands, adrenal medulla, jaws and teeth, and germ cells.

Endoderm (Inner layer of embryo)

Epithelial lining of digestive tract and associated organs (liver, pancreas). Epithelial lining of respiratory, excretory, and reproductive tracts and ducts. Thymus, thyroid, and parathyroid glands.

What process, which is a result of transpiration, can lower the temperature of a leaf and prevent denaturation of various enzymes involved in photosynthesis and other metabolic processes? (Concept 36.5)

Evaporative cooling

Molecular analysis of the homeotic genes, the Hox genes and other regulory genes, such as bicoid, in Drosophila called what?

Evolution of genes that regulate development—homeobox domains A homeobox.

Evolution of what structures may have initiated the mineralization pathways for both teeth and bone?

Evolution of predatory feeding structures

The fly with legs emerging from its head is the result of a single mutation in one gene—a *blank* gene.

Evolutionary Development Biology ("Evo-Devo") A homeotic gene.

What is the study of the evolution of developmental processes in multicellular organisms?

Evolutionary development biology, or evo-devo. Study genes that regulate developmental processes in multicellular organisms. Study genes that regulate development change over evolutionary time. Study evolution of morphological character traits similarities that occur during development.

What are structures that evolve in one context but become co-opt for a different function?

Exapatation

*blank*—membrane potential change. *blank*—Cortical granule release, followed by elevation of fertilization envelope.

Fast—membrane potential change. Slow—Cortical granule release, followed by elevation of fertilization envelope. *Both are mediated by ionic changes across the plasma membrane.

Concept 47.3: Cytoplasmic determinants and inductive signals contribute to cell fate specification.

Fate map: are diagrams showing organs and other structures that arise from each region of an embryo. Classic studies using frogs indicated that cell lineages in germ layers is traceable to blastula cells. If cells are determinated: They can proceed to terminally differentiated state through lineage-dependent mechanisms dependent on cell autonomous signals or they can proceed to terminally differentiated state through position-dependent mechanisms dependent on induction from non cell-autonomous signals.

What is followed by cleavage: rapid cell division without growth?

Fertilization

Dorsal-ventral asymmetry is determined by what?

Fertilization.

Gymnosperms—cycads and Ginkos.

Flagellated sperm formed inside pollen tubes. Very large—300 micrometers. Have more than 50,000 flagella. Lost flagella in Angiosperm.

Plants go through phase changes: juvenile stages prior to adult prior to *blank* stage.

Flowering stage. Regulated by microRNAs.

Fern (vascular) embryogenesis

Foot—absorbs nutrients from gametophyte

Same Hox gene that organize *blank*, *blank* and *blank* in vertebrates are found in lancelets. BF1, Otx, and Hox3 are all what?

Forebrain, midbrain, and hindbrain Are all Hox genes.

What is the difference between frog and tunicate embryo lineages?

Frog embryo lineages are position dependent and develop differently depending on their position in the embryo. Tunicate embryo lineages are lineage-dependent and different cells in the embryo give rise to different specific structures.

In *blank*—animal and vegetal pole.

Frogs

What establishes cell layers and a primitive digestive tube, producing a gastrula?

Gastrulation

These layers are called what (do not confuse with the germ line—the line of non-soma cells containing reproductive cells).

Germ layers

Concept 34.3 Gnathostomes are vertebrates that have jaws.

Gnathostomes include sharks—and above (bony fish amphibians, retiles, mammals). Hox genes duplicated several times—four sets. Forebrain enlarges—acute eyes, olfactory nostrils, electric field detection on head, no eardrum, but have inner ear—whole body catches the sound. Lateral line system (nervous system that senses vibration along sides of fish) developed. Bones gone wild (and external)—Armored jawless fish and jawed Placoderms (450 mya-350 mya) becomes extinct in the Devonian.

Evolution is not what?

Goal-oriented

Which cells help balance water conservation with gas exchange for photosynthesis? (Concept 36.4)

Guard cells

Root pressure sometimes results in *blank*, the exudation of water droplets on tips or edges of leaves. (Concept 36.5)

Guttation

Marking cells to look at lineage in plants

Have a gene that produced a colored gene product after random excision of a transposon. Rare enough to only mark one cell and its offspring.

Ray-finned fishes have what that help buoyancy and probably evolved from lung?

Have swim-bladders that help buoyancy and probably evolved from lungs. *Bony rays support their fins.

Concept 32.2: Animals can be characterized by "body plans"—starts with cleavage patterns

Holoblastic cleavage, complete division of the egg, occurs in species whose eggs have little or moderate amounts of yolk, such as sea urchins and frogs. Syncytial blastoderm in Drosophila (insects), nuclear disions is not accompanied by cell division until 2000-4000 have formed. Meroblastic cleavage, incomplete division of the egg, occurs in species with yolk-rich eggs, such as reptile and bird. Initial development is carried out by RNA and proteins morphogen gradients are deposited in the egg during oogenesis—deposition of bicoid in Drosophila establishes anterior-posterior axis After cleavage, the egg cytoplasm has been divided among many blastomeres, each of which can make sufficient RNA to program the cell's metabolism and further development—develop by induction.

Most animals (not sponges) have which genes?

Homeotic genes

Cetartiodactyla; Artiodactuls: sheep, pigs, cattle, deer, giraffes.

Hooves with an even number of toes on each foot; herbivorous.

Perissodactyla: Horses, zebras, tapirs, and rhinoceroses.

Hooves with an odd number of toes on each foot; herbivorous.

Which genes regulates the development of body morphology?

Hox genes *From homeosis—the conversion of one organ into another which is seen in Drosophila.

The acrosome at the tip of the sperm releases *blank* enzymes that digest material surrounding the egg.

Hydrolytic enzymes

Small changes in regulatory sequences of certain genes lead to major changes in body form. Variation in Hox gene expression controls variation in what segments of crustaceans and insects.

In leg-bearing segments of crustaceans and insects.

*blank*—embryonic stem cells—mammals, "totipotent", can differentiate into any cell line, until 8 cell stage, other organisms later.

Indeterminate

What signals play a major role in pattern formation, development of spatial organization?

Inductive signals

The cellular environment (light in the phytochrome pathway), and the neighboring cells, send signals that cause changes in gene expression. In development, this is called what?

Inductive signals *Thus, cytoplasmic determinants and interactions between cells induce differentiation of specialized cell types.

Upon fertilization of the egg and sperm, the egg surface rotates with respect to what?

Inner cytoplasm.

After fertilization the embryo develops into a segmented larva with three larval stages: *blank*.

Instars

The notochord is a longitudinal, flexible rod between the digestive tube and nerve cord. It provides what kind of support throughout most of the length of a chordate?

It provides skeletal support

The solute potential (osmotic potential) is directly proportional to what? (Concept 36.3)

Its molarity.

Modification of skeletal rods in the anterior pharyngeal slits—evolution of what?

Jaws

What only have one set of Hox genes?

Lancelets and tunicates only have one set of Hox genes. *Lancelets missing genes for long-range transmission of nervous signals. Therefore, those genes are unique to vertebrate lineage.

What have slightly swollen tip of nerve cord/neural tube= rudimentary brain?

Lancets

Leaves generally have *blank* surface areas and *blank* surface-to-volume ratios. (Concept 36.4)

Large surface areas and high surface-to-volume ratios

This negative pressure pulls water in the xylem into the what? (Concept 36.4)

Leaf

The wings and legs of chicks, like all vertebrate limbs, begin as bumps of tissue called what?

Limb buds. *The embryonic cells in a limb bud respond to positional information indicating location along three axes.

What type of fish have rod-shaped bones in fins used for swimming—and walking (?) on ocean floor.

Lobe-finned fishes *Coelacanth found in 1938—found off coasts of Africa and Indonesia.

Proboscidea: Elephants.

Long, muscular trunk; thick, loose skin; upper incisors elongated at tusks.

Many changes in morphology likely result from changes in the regulation of development genes rather than changes in the *blank* of developmental genes.

Many changes in morphology likely result from changes in the regulation of development genes rather than changes in the *sequence* of developmental genes. *For example, threespine sticklebacks in lakes have fewer spines than their marine relatives. The gene sequence the same, but the regulation of gene expression is different in the two groups of fish.

Water potential is measured in which unit of pressure? (Concept 36.3)

Megapascal (MPa) *0 MPa for pure water at sea level and at room temperature.

As water evaporates, the air-water interface retreats further into what type of cell walls? (Concept 36.4)

Mesophyll

Ectotherms regulate their body temperature through behavioral adaptions. Birds and some fast-moving dinosaurs are/were endothermic, capable of maintaining body temperature through what?

Metabolism

Homeotic genes have same linear sequence on chromosomes of flies and what other mammals?

Mice

Cytoskeleton drives infolding. Elongation thickening with what? Contraction and bending with what?

Microtubules. Contraction and bending with Actin filaments.

This rolling in both vertebrates and invertebrates involves similar inductive signals, cell shape change cell's what?

Migration

*Blank* of cartilage may have occurred in the pharyngeal region—conodonts (500 mya) had oral hooks and pharyngeal dentition.

Mineralization

Give an example of Protostome development

Molluscs, annelids, and arthropods *eight celled stage, spiral and determinate Mouth develops from blastopore Schizocoelous: solid masses of mesoderm split to form coelom.

Monotremes and Marsupials

Monotremes and Marsupials Montremes are a small group of egg-laying mammals consisting of echidnas and the platypus. Marsupials included opossums, kangaroos, and koalas. The embryo develops within a placenta in the mother's uterus. A marsupial is born very early in its development. It completes its embryonic development while nursing in a maternal pouch called a marsupium. In Australia, convergent evolution has resulted in a diversity of marsupials that resemble the eutherians in other parts of the world.

Most reptiles lay shelled eggs on land—dinosaurs too. Most reptiles are *blank*, absorbing external heat as the main source of body heat.

Most reptiles are ectothermic, absorbing external heat as the main source of body heat. *Amniote survey: Evolution of reptiles Living amphibians and amniotes split from a common ancestors about 350 million years ago. Fossil evidence indicates that the earliest reptiles lived about 310 million years ago. Reptiles have scales that create a waterproof barrier. Most reptiles lay shelled eggs on land—dinosaurs too.

Gymnosperm

Naked seed, i.e., seeds not enclosed in chambers—just modified leaves of the cone.

What favored taller plants with flat appendages, multicellular branching roots, and efficient transport? (Concept 36.1)

Natural selection

The surface-tension of water creates a *blank* pressure potential - xylem sap is normally under this pressure, or tension. (Concept 36.4)

Negative

Concept 32.2 The history of animals spans more than half a billion years.

Neoproterzoic: 770 mya—sponges. 675 mya—bilateria and three germ layers. Paleozoic: 365 mya—early land animals. Mesozoic: origin and diversification of dinosaurs. Flowering plant and insect diversification (65.5 mya). Cenozoic: diversification of mammals.

*blank*—migratory, derived from ectoderm, neural fold. Form nerves of peripheral nervous system, PNS. Neural tube becomes brain and spinal cord the central nervous system, CNS.

Neural crest cells

Early *blank* land plants lived in shallow water and had aerial shoots. (Concept 36.1)

Nonvascular

Seedless plants—Mosses and Ferns.

Not in pollen tubes. Have spiral structure with lamellar bands of flagella.

Phragmoplast

Occurs during telophase. In network of microtubules and actin—also contains ER, and vesicles.

*blank*—regulation region is the apical ectodermal ridge (AER); the thickened ectoderm at the bud's tip.

One limb bud

Primates: Lemurs, monkeys, chimpanzees, gorillas, humans.

Opposable thumbs; forward-facing eyes; well-developed cerebral cortex, omnivorous.

Concept 18.4 Pattern Formation: setting up the body plan

Pattern formation is the development of a spatial organization of tissues and organs. In animals, pattern formation begins with the establishment of the major axes. Positional information, the molecular cues that control pattern formation, tells a cell its location relative to the body axes and to neighboring cells—will cover this when covering limb development in chordates.

What transports photosynthetic products from sources to sinks? The evolution of xylem and phloem in land plants made possible the long-distance transport of water, minerals, and products of photosynthesis. (Concept 36.1)

Phloem

What type of sap is an aqueous solution that is high in sucrose and travels from sugar source to a sugar sink?(Concept 36.5)

Phloem sap *Phloem sap moves through a sleeve tube by bulk flow driven by positive pressure called pressure flow.

These characteristics increase what process, but also increase water loss through stomata. (Concept 36.4)

Photosynthesis

Plant and Animal Development—similarities

Plant and Animal Development—similarities Outside of early blastoderm in indeterminate (deuterostome) animal embryos (embryonic stem cells), there is a progressive restriction in developmental potential in animal somatic cells. Plant cell types also show restriction in developmental potential as cell lines mature—xylem, phloem, latex cells, fruit (Carpel) cells, mature pollen cells and endosperm.

Who have different homeotic genes, MADs-box gene that regulated development of body morphology?

Plants

Concept 29.1: Land plants evolved from green algae

Plants share the following traits with only charophytes. Rings or rosettes of CESA-cellulose synthase-track along underlying microtubules. Structure of the flagellated sperm. Formation of phragmoplast.

*Blank* occurs when the protoplast shrinks and pulls away from the cell wall. (Concept 36.3)

Plasmolysis

If a flaccid (limp) cell is places in an environment with a higher solute concentration, the cell will lose water and undergo what? (Concept 36.3)

Plasmolysis

The molecular cues that control pattern formation are called *blank*information.

Positional information. *This information tells a cells where it is with respect to the body axes. It determines how the cell and its descendants respond to future molecular signals.

What s the physical pressure on a solution? (Concept 36.3)

Pressure potential

The *blank* is the living part of the cell, which includes the plasma membrane? (Concept 36.3)

Protoplast

Ray-finned fishes: have a bony *blank* covering four or five sets of gills.

Ray-finned fishes: have a bony *operculum* covering four or five sets of gills. *Rays major source of protein for humans.

Xenarthra: Sloths, anteaters, armadillos.

Reduced teeth or no teeth; herbivorous (sloths) or carnivorous (anteaters and armadillos).

Most animals reproduce in what way?

Reproduction and Development Most animals reproduce sexually, with the diploid stage usually dominating the life cycle.

What account for much of the surface area of roots? (Concept 36.3)

Root hairs

Water flows in from the root cortex, generating *blank*, a push of xylem sap. (Concept 36.5)

Root pressure

According to the cohesion-tension hypothesis, transpiration and water cohesion pull water from where? (Concept 36.4)

Roots and shoots

Amphibians—Salamanders (Urodela—tailed ones), Frogs (Anura—tailless ones), and Caecilians (Apoda—legless ones)

Salamanders—show Paedomorphosis or Neoteny—sexually mature juvenile stages—will discuss this later—plants do this too! Frogs—undergo large metamorphosis from legless to very strong legs: Hormonal induction of development. Toads are frogs with leathery skin. Caecilians—Evolved leglessness from common ancestor with other amphibians. Leglessness linked to changes in somite development?

Gymnosperm seed

Seed coat is from the dominant sporophyte, food supply from the female gametophyte.

Angiosperm seed

Seed coat—and carpel—is from the dominant sporophyte food supply from double fertilization—male and female gametophyte.

What is not a shared derived character of vertebrates? Also a major feature of invertebrates.

Segmentation *Segmentation is achieved through the formation of somites.

Large cartilagenous pectoral, pelvic, and caudal (tail) fins in *blank*. Greatly enlarged pectoral fins in *blank*, with whiplike tail that can have venomous brabs.

Sharks and rays

Camivora: Dogs, wolves, bear, cats, weasels, otters, seals, walruses.

Sharp, pointed canine teeth and molars for shearing; carnivorous.

Hyracoidea: Hyraxes.

Short legs; stumpy tail; herbivorous; complex, multichambered stomach.

In angiosperms, what are the elements of conduits for translocation? (Concept 36.5)

Sieve-tube elements

Mesoderm (middle layer of embryo)

Skeletal and muscular systems. Circulatory and lymphatic systems. Excretory and reproductive systems (except germ cells). Dermis of skin. Adrenal cortex.

Embryogenesis differences—in plants in animals

Solid embryo—no blastocoel. No cell-cell movement, gastrulation in plants. "Internal" development protects embryo from desiccation (like amniotes). Ingrowths of maternal placental cell transfer nutrients to developing embryo—and endosperm in seeds. No stored reserves (yolk) for initial embryo development—but in seed plants, a lot of stored reserves in endosperm and cotyledons for post-germination growth. Hence, in non-seed plants—liverworts, mosses and ferns, there is a large dependence on maternal tissues and early absorption of nutrients.

What are blocks of tissue that give rise to segmental structures—in vertebrates, they give rise to vertebrae?

Somites *Somites produce mesenchyme cells that become the ribs and associated muscles.

The ZPA influences development by secreting a protein signal called what?

Sonic hedgehog: positional information. * Implanting cells expressing Sonic hedgehog or transplanting the ZPA into the anterior of a normal limb bub results in a mirror image limb.

Induction in the Frog Embryo: The "organizer" of Spemann and Mangold

Spemann and Mangold transplanted tissues between early gastrulas and found that the transplanted dorsal lip of the blastopore triggered second gastrulation in the host. The dorsal lip functions as an organizer of the embryo body plan, inducing changes in surrounding tissues to form notochord, neural tube, and so its position determines the fate of other cells. A form of position-dependent development in animals.

Water vapor in the airspaces of a leaf diffuses down its water potential gradient and exits the leaf via *blank*. (Concept 36.4)

Stomata

Concept 36.5

Sugars are transported from sources to sinks via the phloem.

Tubulidentata: Aardvarks.

Teeth consisting of many thin tubes cemented together; eats ants and termites.

What reaction is triggered when the sperm meets the egg?

The acrosomal reaction

Which ancestors of land plants absorbed water, minerals, and CO2 directly from the surrounding water. (Concept 36.1)

The algal ancestors

Which axis of the frog embryo is determined during oogenesis—animal anterior, vegetal (yolk) posterior?

The anterior-posterior axis of the frog embryo is determined during oogenesis—animal anterior, vegetal (yolk) posterior. *The dorsal-ventral axis is not determined until fertilization. *The right-left axis is largely symmetrical. .

A morphogen that determines head structures. One maternal effect gene, the *blank* gene, affects the front half of the body—has homeobox domain, but not a Hox gene.

The bicoid gene

What leads to expression of dorsal-ventral specific gene expression?

The cortical rotation brings molecules from one portion of the vegetal cortex to interact with molecules in the inner cytoplasm of animal hemisphere.

In mammals, experiments suggest that orientation of the *blank* nuclei before fusion may help establish embryonic axes.

The egg and sperm nuclei.

What is the innermost layer of cells in the root cortex?(Concept 36.3)

The endodermis

An embryo whose mother has no functional bicoid gene lacks what?

The front half of its body and has duplicate posterior structures at both ends.

In Drosophila, cytoplasmic determinants in the unfertilized egg determine the *blank* before fertilization.

The life Cycle of Drosophila In Drosophila, cytoplasmic determinants in the unfertilized egg determine the *axes* before fertilization.

The evolution of xylem and phloem in land plants made what possible? (Concept 36.1)

The long-distance transport of water, minerals, and products of photosynthesis

What is the Morphogen Gradient Hypothesis?

The morphogen gradient hypothesis: gradients of substances called morphogens establish an embryo's axes and other morphological features. Experiments shows that bicoid protein is distributed in an anterior to posterior gradient in the early embryo. They identified a specific protein required for some early steps in pattern formation. They increased understanding of the mother's role in embryos development. They demonstrated a key developmental concept that a gradient of molecules can determine polarity and position in the embryo.

What forms above the notochord by infolding and pinching off the neural plate?

The neural tube.

What differences between the two sides of the blastoderm establish the dorsal-ventral axis?

The pH differences *Axis formation in Birds and Mammals In chicks, gravity is involved in establishing the anterior-posterior axis.

What happens if the lost water is not replaced by sufficient transport of water? Concept 36.5

The plant will lose water and wilt.

Concept 36.4

The rate of transpiration is regulated by stomata

The cell marked with color always give rise to only one sector, if the sectors are lineage-dependent and give rise to multiple sectors, if position-dependent.

The root-shoot boundary is zero. Many cell linages arise and end within this boundary. Therefore, plant development is position dependent, not lineage dependent.

The second region is the *blank*: mesodermal tissue under the ectoderm where the posterior side of the bud is attached to the body.

The second region is the zone of polarizing activity (ZPA),

At night root cells continue pumping mineral ions into the xylem of the vascular cylinder, lowering what? (Concept 36.5)

The water potential

Concept 32.1 Animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers.

There are exceptions to nearly every criterion for distinguishing animals from other life-forms. Animals are heterotrophs that ingest their food. Animals are multicellular eukaryotes. Their cells lack cell walls. Their bodies are held together by structural proteins such as collagen. Nervous tissue and muscle tissue are unique, defining characteristics of animals.

Axis Formation in Vertebrates—the Frogs A body plan with bilateral symmetry is found across a range of animals. This body plan exhibits asymmetry across the which axes?

This body plan exhibits asymmetry across the dorsal-ventral and anterior-posterior axes.

The products of photosynthesis are transported through phloem by the process of? (Concept 36.5)

Translocation

Plants lose a large amount of water by what process? (Concept 36.5)

Transpiration

Concept 36.3

Transpiration drives the transport of water and minerals from roots to shoots via the xylem.

The *blank* pull on xylem sap is transmitted from leaves to roots. (Concept 36.4)

Transpirational

Bilateria are *blank* and form a third layer the mesoderm.

Triploblasts

What is the pressure exerted by the plasma membrane against the cell wall, and the cell wall against the protoplast? (Concept 36.3)

Turgor pressure

Turtles and Snakes—Changes in vertebra development

Turtles and Snakes—Changes in vertebra development Some turtles are desert, some are aquatic, and some are sea turtles (the largest). The phylogenetic position of turtles remains uncertain. All turtles have a boxlike shell made of upper and lower shields that are fused to the vertebrae, clavicles and ribs. Snakes are legless, but they have multiple vertebrae. Legs lost evolutionarily—lepidosaurs that evolved from lizards. Is leglessness linked to somite dev? Carnivorous feeding adaptions of snakes: chemical sensors, heat-detecting organs, venom, loosely articulated jawbones and elastic skin. Movement through coiling and sequential lifting of scales.

Who have two or more sets of Hox genes?

Vertebrates have two or more sets of Hox genes. *Additional genomic complexity gives rise to skull and backbone in somites.

Water can cross the cortex via the *blank* or *blank*. (Concept 36.3)

Water can cross the cortex via the symplast or apoplast.

Water flows from the regions of *blank* water potential to regions of *blank* water potential. (Concept 36.3)

Water flows from the regions of higher water potential to regions of lower water potential.

Concept 21.6 Comparing genome sequences provides clues to evolution and development

Widespread Conservation of Development Genes among Animals. Genic information shows that minor differences in gene sequence or regulation can result in striking differences in form.

What transports water and minerals from roots to shoots? (Concept 36.1)

Xylem