Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

125 Cards in this Set

  • Front
  • Back
_______ is the idea that a miniature human called a homunculus is present in human sperm or eggs.
In an attempt to reverse the restriction to nuclear potency that occurs during amphibian development, _______.
nuclei were subjected to serial transplantations
_______ was the first to clone a mammalian organism.
Hammerling's conclusions from his work with Acetabularia
Simple developmental events in unicellular eukaryotes are under nuclear control, although there are short-lived cytoplasmic factors involved in the expression of the nuclear information
Puffs on polytene chromosomes are sites where _______ is occuring.
Obstacles to using adult stem cells.
-difficult to isolate large quantities
-no knowledge of how to induce them to differentiate into all types of mature tissues
-they are not totipotent
-unlimitied growth potential might lead to tumors
_______ is considered to be the inducer of the lac operon.
Cellular activities in E.coli in the presence of high levels of glucose.
-adenyl cyclase in inactive
-cAMP levels drop
-enzymes involved in utilization of lactose are not expressed
-RNA polymerase does not bind to promoter of the lac operon
In E.coli, the gene araC codes for a protein that is involved in utilizing the sugar arabinose as a source of carbon and energy. Transcription of araC is most likely _______.
turned off in the presence of glucose
Proteins are made of subunits called _______.
amino acids
Proteins that recognize and bind DNA sequences to help regulate the process of transcription are _______.
transcription factors
The production of abundant quantities of ribosomal RNA in amphibians is largely the result of _____.
amplification of rRNA genes
A nucleosome consists of DNA wrapped around a core of _____.
histone proteins
When it functions properly, the bicoid gene production in Drosophila determines the formation of _____ structures.
Acrosomal Reaction in Sea Urchins
-triggered by species-specific interaction between molecules on the sperm and molecules in the jelly coat of egg
-enzymes that digest path thru jelly coat are released from sperms acrosome
-the release of enzymes is process called exocytosis
-extension of sperm head, called acrosomal process, grows thru jelly coat to reach the vitelline layer of egg
During fertilization in sea urchins, the hardening of the fertilization membrane is catalyzed by enzymes released from ______.
the egg's cortical granules
Capacitation in mammals _____.
is triggered by secretions in the female's reproductive tract
Based on what we know about the amount and distribution of yolk in the human egg, the best hypothesis about early cleavages in the human embryo is that they are _____.
holoblastic and symmetrical
Of the following, the _____ is the earliest developmental stage.
At the end of _____, the embryo consists of three primary germ layers and a well developed archenteron.
The inner lining of the vertebrate gut and all its associated organs is derived from _____.
The filopodia fibers that participate in the expansion of the archenteron during gastrulation in sea urchins are extensions of _____.
mesenchyme cells
Mesenchyme cells that migrate into the blastocoel during gastrulation in sea urchins will become _____.
mesoderm that forms internal organs
In protostomes such as mollusks and annelids, the opening of the gut where the archenteron first starts to form becomes the _____.
Cortical Rotation in amphibians
-tirggered by sperm penetration
-involves rotation of the peripheral layer of cytoplasm called the cortex
-causes vegetal pole cytoplasm to come in contact with animal pole cytoplasm in a region called the gray crescent
-gray crescent marks future dorsal side of embryo
Skin pigment cells, teeth, and some of the bones and muscles of the skull are all derivatives of _____.
neural crest cells
The _____ is a rod of condensed mesoderm that provides support for the early vertebrate embryo.
Collagen is released by cells of the _____ to form the vertebrate of our backbones.
lateral and median ossification centers
The vertebrate neural tube is derived from _____.
Some cells in the neural tube are induced to become motor neurons by _____.
ventral plate cells
The white matter in the mammalian spinal cord consists primarily of _____.
bundles of nerves that run longitudinally through the cord
Normally, fertilization in humans occurs in the _____.
In amniotes such as chickens and humans, the sac that immediately surrounds that embryo and protects it from dessication and mechanical shock is the _____.
In humans, the fetal contribution to the placenta is derived from the _____.
Conjoined (Siamese) twins in humans can form when two fetuses share the same _____.
A _____ is an organic compound that is produced in one part of the body, is transported to other parts of he body through the blood or lymph, and then elicits a change in cells that have surface or internal receptors for the compound.
-members of a larger class of molecules called CAMs
-binding btwn 2 cadherin molecules is dependent on calcium
-changes in their expressions are involved in neural tube formation of vertebrates
-migration of neural crest cells occurs when they stop expressing any type of cadherin
A morphogenic gradient of the sonic hedgehog protein is responsible for establishing the _____ axis of the vertebrate limb.
anterior to posterior
Which is an accurate conclusion of the experiments performed by Spemann in which presumptive neural ectoderm was transplanted to regions of presumptive epidermis in early gastrula and late gastrula amphibian embryos?
At some point during gastrulation, cells become determined to become neural ectoderm.
When Spemann and Mangold transplanted the dorsal lip of the blastopore from one early amphibian gastrula to another, the effects were the same as when _____.
double cortical rotations were induced
The process of making RNA using DNA as a template is _____.
Ribosomes and transfer RNAs are used during _____.
Cap formation in Acetabularia
mainly under nuclear control, but a short-lived cytoplasmic factor is involved in the process
In the studies performed by Briggs and King with Rana pipens, the unfertilized eggs were treated with ultraviolet light to _____.
destroy the nuclear material
Beerman's work with insect polytene chromosomes
differentiation is the result of differential gene expression in genomically equivalent cells
Wilmut attempted to reverse the restriction to nuclear potency during the cloning of Dolly by _____.
starving cells
Polytene chromosomes in Drosophila are formed when _____.
cells undergo DNA replication without cell division
Most researchers believe that the restriction to nuclear potency that occurs during amphibian development _____.
is the result of chemical modifications to the DNA during development
Allolactose _____.
binds to the lac repressor and prevents it from binding to its target DNA sequence
The _____ is a positive transcription factor.
CAP-cCAMP complex
In E.coli, enzymes involved in synthetic (anabolic) pathways are typically ______.
repressed by the product of the synthetic pathway
The acetylation of histone tails affects the ability of DNA to fold into _____.
One of the main mechanisms of generating antibody diversity involves _____.
differential DNA rearrangement of antibody genes
_____ is when the exons of a gene transcript are joined together in different combinations.
Differential mRNA splicing
Slow block to polyspermy in Sea Urchins
-1 min to establish after sperm penetration
-involves release of internal stores of calcium from the egg's ER
-calcium induces the cortical granules to fuse with the egg plasma membrane
-the cortical granules release enzymes that dissolve the connection between the plasma membrane and the vitelline layer
During the fast block to polyspermy, the electric potential of the eggs membrane is changed because of _____.
the influx of sodium from the sea water
The point of sperm entry during amphibian fertilization marks the future _____ end of the embryo.
Holoblastic and perfectly symmetrical cleavages are associated with _____ eggs.
Early Cleavage in Amphibians
-involve cell divisions without extensive cell growth
-cells produced are called blastomeres
-first 2 cleavags occur in vertical plane
-3rd cleavage occurs in horizontal plane
The cells that undergo invagination at the vegetal plate of the sea urchin embryo are destined to become _____.
endoderm that forms the inner lining of the gut
When amphibian eggs were imbedded in gelatin prior to fertilization, _____.
the embryo died as a mass of ventral-like cells
In chicken embryos, the _____ is an outpocketing of the gut where wastes generated during development are stored.
In humans and other mammals, the exchange of wastes and nutrients between the mother and the fetus occurs in the _____.
Bone is formed when calcium causes ______ to harden.
Nerve cells are derived from _____.
Muscle is derived from _____.
The gray matter of the vertebrate spinal cord consists primarily of _____.
motor and sensory neurons that send and receive signals from peripheral parts of the body
The fully developed vertebrate spinal cord is protected by _____.
vertebrae of the backbone
During the development of the vertebrate spinal cord, cells are induced to become motor neurons by _____.
ventral floor plate cells of the neural tube
Microtubes and microfilaments are components of _____.
the cytoskeleton
When presumptive neural ectoderm from a late gastrula amphibian embryo is transplanted to a region of presumptive epidermis, the result is that _____.
the transplanted tissue develops into a secondary neural plate
The zone of polarizing activity (ZPA) determines pattern along the _____ axis of the developing chicken limb.
If a newt limb is severed just below the wrist, a new wrist and hand will regenerate. If the limb is severed below the elbow, _____.
a new elbow, wrist, and hand will form
Most mutations are the result of mistakes made during the process of _____.
Aristotle was the first to propose _____ as the basis for animal development.
The fact that polytene chromosomes in different larval tissues have the same sizes and same banding patterns is evidence for _____ in Drosophila.
genomic equivalence
Mutations such as bicoid in Drosophila support the idea that _____.
genes play an important role in controlling early developmental events
Gurdon was able to partially reverse the loss of nuclear potency that occured during amphibian development by _____.
subjecting nuclei to several rounds of serial transplantations
trp operon in E.coli
-trp repressor is an allosteric protein
-trp operon is under negative control
-trp repressor binds to the trp operator only when the repressor is bound to tryptophan
When E.coli has access to both lactose and glucose, RNA polymerase cannot bind to the promoter of the lac operon because ______.
the CAP-cAMP complex is not bound to the CAP binding site
Human Chromosomes
-some of the larger ones have over 100 million base pairs of DNA
-each chromosome has a single centromere that is important during cell division
-some chromosomes have over a thousand different gene sequences
-the specialized ends of the human chromosome are called telomeres
_____ is the theory that during development the adult form emerges gradually from a formless egg.
In E.coli, the gene argB codes for an enzyme that catalyzes one of the steps in the synthesis of the amino acid arginine. Expression of argB is most likely ______ by arginine.
When E.coli has access to _____, the CAP-cAMP complex is bound to the CAP binding sit and the lac repressor is bound to the operator.
neither glucose nor lactose
Of the following, _____ was the first to provide evidence that genes control early developmental events in multicellular animals.
Adult stem cells are _____.
The rRNA genes in amphibians provide a nice example of gene regulation by _____.
gene amplification
Cleavages, such as those that occur during early amphibian development, are unusual for cell divisions because they _____.
occur in the absence of cell growth
The contraction of filopodia fibers is important for _____ during gastrulation in sea urchins.
extension of the archenteron
In humans, the _____ is the site of early blood cell formation.
yolk sac
Cleavages of microlecithal eggs are ______.
holoblastic and symmetrical
Human eggs are _____.
The merging of several cell layers into a single layer is an example of ______.
convergent extension
In amphibians, the point of sperm entry marks the future _____ of the embryo.
ventral side
After gastrulation in both sea urchins and amphibians, the archenteron is lined with ______.
______ is any point during the developmental process when the developmental potential of a cell is narrowed.
From his studies of polytene chromosomes, _____ demonstrated that during development, cells retain genomic equivalence but exhibit differential gene activity.
Each three-letter codon in mRNA codes for a single ______.
amino acid
Before a mRNA can be translated into a functional protein, its _____ must be removed.
The structure formed by the wrapping of DNA around a core of histone proteins is called _____.
a nucleosome
Histone tails are important for the formation of compact ____ structures.
_____ described how the lac operon is regulated by lactose and glucose in E.coli.
Jacob and Monod
In E.coli, threonine is an amino acid that is synthesized in a multi-step pathway that starts with aspartic acid. the gene thrA codes for and enzyme that catalyzes one of the steps in this pathway. Transcription of thrA is most likely _____.
turned off by threonine
Allosteric proteins are proteins that _____.
change their configuration upon binding to a substrate
The cell divisions that are associated with early cleavages in amphibians are unusual because _____.
cell division occurs without an increase in cell size
Meroblastic cleavage is associated with _____ eggs.
The bicoid mRNA that determines where the head will form in a Drosophila embryo is made by _____.
maternal cells that pump bicoid mRNA into the egg as the egg matures
At the beginning of gastrulation, the vertebrate embryo is called the _____.
The inner lining of human intestines is derived from _____.
An example of _____ is when multiple cell layers merge into a single layer.
convergent extension
In deuterostomes, the second opening of the archenteron to the outside of the embryo is the future _____ of the organism.
In his studies of amphibian development, John Gerhard ____ and the result was the formation of twin embryos joined at their bellies.
centrifuged eggs after fertilization
Sensory impulses from peripheral parts of the body enter the spinal cord primarily through its _____.
The vertebrate spinal cord is protected by the _____.
spinal column
The vertebrate brain is a complex derivative of a portion of the embryonic structure.
the neural tube
In mammals, the _____ becomes the fetal contribution to the placenta.
Ribosomes are essential components during the process of _____.
The polytene chromosomes found in many insect larval tissues are formed when ____.
cells undergo DNA replication without cell division
Steward demonstrated that they cells of the carrot plant root _____.
were totipotent
Optimal (maximal) binding of RNA polymerase to the promoter of the lac operon occurs when _____.
lactose is available, but glucose is absent
The activity of adenyl cyclase is inhibited by _____.
Testosterone and Human Development
-testosterone is an example of a class of organic compounds called hormones
-produced by the testes and transported to other body parts of the body through the bloodstream
-the testosterone/testosterone receptor complex functions as a transcription factor
-true hermaphrodites are individuals with both ovaries and testes
The _____ of histones is often associated with the unpackaging of DNA and activation of transcription.
_____ is the enhancement of sperm function in the human female reproductive track.
In sea urchins, the acrosomal reaction is activated by species-specific interactions between factors in the sperm and factors ____.
in the jelly coat of the egg