BIO 117 Final Exam Introduction to Animal Development Lecture 7

Part 1

What is the greatest challenge in biology?

Understanding development

What is Cell Division?

Tightly controlled, most cells stop dividing when they mature, replaces skin, blood, repair wounds, and immune sytem

What is Cell-Cell Interactions and Differentiation?

Cells interact constantly during development through signaling molecules

What is cytoplasmic determinism?

Regulatory molecules that are unequally distributed to daughter cells

What is induction?

One daughter cell receives a signal that the other does not

What are cell movement and cell expansion?

Animal cells move at various developmental stages

What is programmed cell death called?

Apoptosis

Genetic Equivalence of cells

Differentiated cells contain all the genes in the genome

How does differential gene expression occur?

Chromatin remodeling, transcriptional control, alternative splicing, and selection destruction of mRNAs, translation role, and activation or deactivation of proteins

What is genetic regulatory cascades?

A set of linked regulatory genes

Genetic regulatory process?

One activated gene turns on the expression of other regulatory genes, and cells receive more detailed instructions on where and what

What are Morphogens?

Are pattern formation molecules that are established spatial organization

What are Gap Genes?

Control formation of large body regions

What are pair-rule genes?

Expressed in alternating bonds and control formation of individual segments

What are segment polarity genes?

Expressed in parts of each segment and create regions within segments

What is pattern formation?

Describe the events that determine spatial organization

What is the Bicoid Morphogen?

Developmental defects in offspring, pattern-formation mutants on the body plan, and affects anterior-posterior axis

What happens with high bicoid concentrations?

Tells a cell is is in the anterior

What are homeotic genes?

Make a gene family in all organisms that have them

What happens in animals with homeotic mutations?

Lead to the wrong body part forming in the wrong place

Biologists use transplantation studies to?

Figure out when a cell becomes committed to particular path, moved to new locations within a developing embryo

What does determination mean?

The commitment of a cell to particular fate, and become more determined during development

Hind limb loss in snakes is due to failure to produce the signaling molcule called?

Sonic Hedgehog

KT: Zygote

Fertilized egg first cell formed when sperm and egg unite

KT: Embryo

Early developing organisms after fertilization

KT: Developmental biology

Study of how organisms grow and develop

KT: Differential

Process where cells become specialized in structure and pattern

KT: Differential gene expression

Different cells turn different genes on/off causing specialization

KT: Genetic Equivalence

Most cells contain the same DNA despite different functions

KT: De-differentiate

Specialized cell reverts to a less specialized state

KT: Clone

Genetically identical copy of a cell or organism

KT: Epigenetic inheritance

Inheritance of gene activity changes with out DNA sequence changes

KT: Commitment

Cell becomes restricted to a certain developmental path

KT: Determined

Cell is committed to a specific fate even if moved somewhere else

KT: Master Regulator

Gene controlling expression of many other genes in development

KT: Stem Cells

Unspecialized cells ale to self renew and differentiate

KT: Self-renewal

Stem cells divide to make more stem cells

KT: Embryonic Stem Cells

Stem cells from embryos that can become many cell types

KT: Pluripotency

Ability to become nearly any body cell type

KT: iPSCs

Adult cells reprogrammed into pluirpotent stem cells

KT: Cytoplasmic determinants

Molecules in egg cytoplasm influencing cell fat

KT: Induction

One cell influences development of another via signaling

KT: Gastrualtion

Embryo rearranges into germ layers

KT: Apoptosis

Controlled cell death during development

KT: Pattern formation

Organized body structures in correct locations

KT: Morphogen

Signaling molecule that forms concentration gradients to guide development

KT: Maternal effect mutations

Offspring phenotype affected by mothers genotype

KT: Homeotic Genes

Genes controlled placement of body parts

KT: Tool Kit Genes

Highly consumed genes controlling body plan development

KT: Evo-Devo

Stuyd how how development influences evolution

KT: Cleavage

Rapid cell divions after fertilization without growth

KT: Blastula

Hollow ball of cells formed after cleavage

KT: Gastrula

Embryo after gastrulation with germ layers established

KT: Organogenesis

Formation of organs from germ layers

KT: Notochord

Flexible rod supporting embryos in chordates

KT: Neural Tube

Embryonic structure that develops into brain and spinal cord

KT: Somites

Segmented blocks of mesoderm that forms muscles, vertebrae and skin

TU: Order of Development

1. Fertilization

2. Cell cleavage

3. Gastrulation

4. Organogenesis

Tu: At what stage do the primary layers form?

During gastrulation

TU: What germ layer forms the neural tube?

Ectoderm

TU: What germ layer forms somites?

Mesoderm

TU: Why does position within a somite matter?

Cells receive different signals depending on location, causing different genes to turn on/off and leading to different cell fates

TU: Scientific term for programmed cell death?

Apoptosis

TU: Why is apoptosis normal in development?

It helps shape structures and remove unnecessary cells

TU: Similarities in animals’ development tell us what?

Animals share similar conserved genetic program/tool kit genes, suggesting common ancestry

TU: Morphogen

Signaling molecule that creates concentration gradient and gives cells positional information

TU: Gap Genes

Establish broad regions of the embryo

TU: Pair-Rule Genes

Divide embryo into repeated segment

TU: Segment Polarity Genes

Define the front, back orientation with each segment

TU: Hox Genes

Determine what body structures each segment becomes

TU: Effector Genes

Carry out actual development of tissues/organs/proteins

TU: Morphogen Mutation

Major body pattern problems

TU: Gap Mutations

Missing large body regions

TU: Pair Rule Mutations

Every other segment missing

TU: Segment polarity

Segments reversed or disorganized

TU: Hox Mutation

Body part develops in wrong location

TU: Effector Mutation

defective tissues/organs formed