Factors that Influence Development

Unequal distribution of cytoplasmic material in the egg causes what result?

development of embryonic axes

(Note: animal/vegetal poles

When eggs have unequal distribution of cytoplasmic material, what is the effect on the daughter cells?

daughter cells have

different qualities of

cytoplasmic substances

What substances in the cytoplasm influence the subsequent development of each daughter cell?

cytoplasmic determinants

What developmental effect influences one cell/group of cells over neighboring cells?

embryonic induction

Which cell/group of cells secrete chemicals that diffuse among neighboring cells, and influence their development?

organizers (controller cells)

Which region of the embryo functions as a primary organizer of the blastopore?

dorsal lip

The dorsal lip influences the development of what structure?

notochord

What visual structure is formed from the ectoderm of the head?

lens of the eye

Which part of the embryonic brain induces lens formation?

optic vesicle

(Note: touches a portion of the ectoderm of the head)

Which genes control development by turning on/off other genes that directly affect the development of body segments?

homeotic (Hox) genes

An experiment in which animals found that mutant homeotic genes resulted in wrong body parts in wrong places?

fruit flies

What is a unique DNA segment of 180 nucleotides?

homeobox

(Note: highly conserved

across species)

A homeobox identifies a particular class of genes that control what process?

development

A homeobox encodes which protein that can bind DNA?

homodomain

What are mutations that affect a process as fundamental as segmentation, and cause death at embryo/larval stage?

embryonic lethals

What is programmed cell death that is part of normal cell development?

apoptosis

(Note: destroy webbing

around fingers and toes)

In which systems is apoptosis necessary?

nervous system and immune system

What are characteristics of apoptosis?

1. blebbing

2. cell shrinkage

3. nuclear fragmentation

4. chromatin condensation

5. chromosomal DNA fragmentation

In mammals, which organelles play an important role in apoptosis, which typically affects single cells?

mitochondria

What is a cell said to be if its final form cannot be changed?

determined

Which influences become diminished with each successive cell division?

cytoplasmic influences

Cells can be traced during development to build which information tool?

lineage map

What is the process by which cells become specialized in structure and function?

cell differentiation

What are referred to as induced pluripotent stem cells?

fully differentiated cells that can be altered under the proper conditions

What process occurs when one cell type affects the direction of differentiation of another cell type?

induction

What is the generation of tissue organization and shape in embryos?

morphogenesis

(Note: traced back to changes in shape, motility, and other characteristics of the cells that make up the embryo)