1. Define the following terms (use your own words): development, growth,
differentiation, histogenesis, organogenesis, morphogenesis, reproduction,
tissue, organ, organ system, and organism.
Growth : increase in size and mass (e.g. growth of organism = increase in cell
numbers, or cell growth = increase in cell volume)
Development : process of growth, differentiation and reproduction of an
organism (includes embryogenesis, postembryonic development and
Differentiation : the structural adaptation (change) of an individual cell (or
other parts of organism) which enables it to perform a particular function
Histogenesis : process by which different tissue types form during
Organogenesis : process by which different organs form during development
Morphogenesis : is ‘the shaping of an organism by embryological processes of
differentiation of cells, tissues, and organs and the development of organ
systems according to the genetic “blueprint” of the potential organism and
Reproduction : The sexual or asexual process by which organisms generate
new individuals of the same kind
Tissue : Part of an organism consisting of an aggregate of cells having a
similar structure and function. (cartilage, epithelium…..)
Organ : A fully differentiated structural and functional unit in an animal
(organism) that is specialized for some particular function. (liver, heart, brain….)
Organ system : Individual organs having specialized function(s) group into
organ system (nervous system, respiratory system…)
Organism : A living thing that has (or can develop) the ability to act or function
independently.(= prokaryotes, protists, plants and animals)
2. Distinguish between growth and differentiation. Give an example where
each occurs independently of the other.
-example is growth is cleavage
-cleavage and blastulation -example of differentiation is irreversible cell fate, cells aggregating into
tissues and perform a certain function
-stem cell turning into a red blood cell
of each otherh between growth and differentiation with an example were each occurs independently
a. Growth if the process of an entity increasing its size, mass, number of cells and volume whereas
differentiation is when structural adaptation of a cell or a part of an organism occurs so that it can
perform a function.
b. During embryogenesis, growth occurs near the beginning where the zygote divides to increase its
number of cells and size whereas differentiation occurs much later on when the cells become
specific tissues and have specific function.
ii. Differentiation = hematopoietic stem cell becoming red blood cell
3. Explain the following statement: "The entire life history of animals is
-in summary: birth, reproduction, and death
4. What are the (two) major questions that are addressed by the discipline of
5. Define (explain what it is) the following terms: chemotaxis, resact,
agglutination (of sperm to jelly coat), capacitation, acrosome, bindin,
acrosomal filament (process), activation (of the egg), cortex (of an egg),
cortical granules, vitelline envelope or membrane, fertilization envelope or
membrane, zona pellucida
Chemotaxis: The characteristic movement of an organism or cell along a
chemical concentration gradient either toward or away from the chemical
Resact: A small 14 AA peptide released by the egg jelly (in sea urchins)
that reacts with sperm as a chemoattractant, leading to the sperm moving towards
Agglutination: The process of binding the sperm and the egg by species-
specific proteins (bindin on sperm) (species-specific event #2)
-is the process when the bindin on the acrosomal process binds to the
bindin receptor (ERB1) on the egg cell membrane
Capacitation: The activation/maturation of sperm cells (esp. membrane)
within the female reproductive system.
Acrosome: Is a vacuole formed as a germ cell differentiates into a sperm. It
is filled with lytic enzymes by the golgi apparatus and it migrates to the tip of the
sperm ‘head’. When the sperm binds with specific proteins on the egg the vacuole is ruptured towards the external environment, disintegrating the
egg’s protective layers.
Bindin: Is a protein represented on the external membrane of the sperm
after the acrosomal reaction takes place; it lines the acrosomal filament and binds
to the egg membrane.
-bindin is found on the acrosomal process (acrosomal process only found in
Acrosomal Filament:an actin microfilament extension from the head of the
sperm that grows where the acrosomal vesicle had previously erupted.
Activation (of the egg): Begins by fusion of the sperm and egg membrane.
Early phase, dependent on transient increase of intracellular calcium, leads
to positively charged cell (excess sperm cannot bind), crosslinkage leads to
stiffer fertilization envelope. Late stage, calcium increase inhibits MAP
kinase, leads to DNA and protein synthesis, including cyclin B and cdk1
initiates cell division.
Cortex: a gel like shell just under the egg cell membrane, high in globular
actin (which polymerizes into microfilaments following fertilization) and contain
Cortical Granules: structures homologous to the sperm’s acrosome. They
are formed by the Golgi and contain enzymes which prevent sperm entry after
fertilization (slow block).
Vitelline Envelope/Membrane: an extracellular matrix (in invertebrates)
which is responsible for sperm-egg recognition, analogous to the zona pellucida
Fertilization Envelope/Membrane: The cavity formed, filled and fused
between the vitelline envelope and the egg\ membrane. It is filled with enzymes of
the cortical granules, and begins to grow from the point of cell entry. Not seen
in mammals. it is a modified vitelline envelope
Chemotaxis: movement toward or away from a chemical
Acrosome (acrosomal vesicle):
6. List and briefly describe adaptations which increase the probability that a
sperm and egg will find one another and that successful fertilization will
follow. Over-production of gametes: huge numbers of sperm produced and released by
the males as to increase the chance of contact between sperm and egg.
Behavioral modifications in the organism: mating calls and behaviours
External vs. interna