Unit I & II Flashcards
Fertilized egg
Zygote
Study of animal development from the stage of an organism that exist between fertilization and birth.
Embryology
What are the three major approaches to studying embryology
Anatomical approaches
Experimental approaches
Genetic approaches
A relatively slow process of progressive change
Development
A discipline that studies embryonic and other developmental processes
Developmental biology
The science that seeks to explain how the structure of organisms change with time
Developmental biology
What are the objectives of developmental biology?
• it generates cellular diversity and order within each generation
• it ensures the continuity of life from one generation to the next
What are the seven general questions by developmental biologist?
• Question of differentiation
• Question of morphogenesis
• question of growth
• question of reproduction
• question of evolution
• question of environmental integration
• Question of regeneration
It is the generation of cellular diversity
Differentiation
Mechanism where by different sorts of cells arise
Cell differentiation
Each cell owes its special character to
Particular proteins coded by particular genes
It is the creation of ordered form
Morphogenesis
It is the cell and tissue movements that gives a developing organ or organism its shape in three dimensions
Morphogenesis
It refers to increase in size and the control of proportion between body parts
Growth
It is currently the least well understood aspect in terms of molecular mechanism
Growth
The stages of development between fertilization and hatching
Embryogenesis
What are the six fundamental processes in the pattern of embryogenesis
- Fertilization
- Cleavage
- Gastrulation
- Organogenesis
- Metamorphosis
- Gametogenesis
It is the fusion of the mature sex cells, the sperm and egg.
Fertilization
It is a series of extremely rapid mitotic divisions that immediately follow fertilization
Cleavage
It is the hollow ball of cells during cleavage
Zygote cytoplasm
During cleavage the enormous volume of zygote cytoplasm is divided into numerous smaller cells called
Blastomeres
By the end of cleavage the blasting is have usually formed a sphere called
Blastula
It is the space between the blastomere
Blastocoel
They are the opening in the blastula
Blastopore
It is a series of extensive self rearrangements
Gastrulation
The embryo contains three germ layers that will interact to generate the organs of the body. What are those layers?
Endoderm
Mesoderm
Ectoderm
Embryo transforms from a one dimensional layer of epithelial cells and reorganizes into a multilayers and multidimensional structure called
Gastrula
The cells interact with one another and rearrange some cells to produce tissues and organs
Organogenesis
It is the process of formation of organs from three germ layers
Organogenesis
Change of form or structure in an individual after hatching or birth
Metamorphosis
It is the development of gametes; usually not completed until the organism has become physically mature
Gametogenesis
Cells which give rise to the individual body
Somatic cells
Cells which contribute to the formation of a new generation
Germ cells
What type of Fertilization happens in most species of frog
External fertilization
Amphibian metamorphosis is initiated by hormones from the
Tadpoles thyroid gland
The speed of metamorphosis depends on
Environmental pressure
What are the major model organism used an example of how all animals develop
Mouse
Chick
Frog (Xenopus)
Zebra fish
Fruit fly (Drosophila)
Nematode (Caenorhabditis elegans)
Characteristics of the big six model organisms
• Availability and cost
• Access and micromanipulation
• They have special properties that allow their mechanisms of development to be easily observed
• Can be easily manipulated physically or genetically
• Have relatively fast development period
• Genomes have been mapped
It is the visible specialization of the cytoplasm
Germplasm
It is present in the egg that program cells that inherit to become germ cells
Cytoplasmic determinant
Is the production of mature sperm cells
Spermatogenesis
It undergoes rapid mitosis to produce more stem cells before puberty
Spermatogonia
Hormone that modifies spermatogonia division
Follicle-stimulating hormone (FSH)
How many spermatids does one primary spermatocyte produces
Four
How many days does spermatogenesis takes place
64 - 72 days
It is the process of development of mature ova
Oogenesis
What is the difference between the female and male gametes regarding their cell size and structure
Sperm are tiny, motile, and equipped with nutrients in seminal fluid
Egg is large, non-motile, and has nutrient reserves to nourish the embryo until implantation
What are the parts of mature sperm
Head
Tail
Neck or midpiece
A part of mature sperm where haploid nucleus little cytoplasm and acrosome are located
Head
A part of the mature sperm where mitochondria and centriole are located
Neck or midpiece
It is also called as propulsion system
Tail
What are the structures of a flagella
It must allows from to travel long distance using plenty of energy
Axoneme
Microtubules in a 9 + 2 configuration
It is the motor portion of the flagella
Axoneme
It is the acquired ability of the sperm to bind the egg
Capacitation
It stores all materials for beginning of growth and development
Ovum
What are the parts of the egg
Cytoplasm
Haploid nucleus
Cell membrane
Extracellular envelope
Cortex
Cortical granules
Egg jelly
Zona pellucida
Cumulus
It contains glycoproteins essential for species specificity and sperm binding
Vitelline envelope
It is located beneath the cell membrane
Cortex
It attracts or activates sperm in some species
Egg jelly
It is an extra coating made of extracellular matrix in mammals
Zona pellucida
It is a layer of cells that nurture the egg innermost layer in mammals
Corona radiata
The fusion of two gametes to create a new individual with the genome different from both parents
Fertilization
What are the two major goals of fertilization
• Joining of genetic material to create new variations (sex)
• creation of a new organism (reproduction)
What are the four major events of fertilization
- Sperm and egg make contact and must recognize each other as the same species
- One (and only one) sperm enter the egg
- Fusion of the genetic material
- Activation of egg to begin development
What are the steps of recognition of sperm and egg
- Chemoattraction
- Exocytosis
- Binding
- Passage
- Fusion
What is the peptide that an diffuse in sea water and attracts sperm to egg and acts as a sperm-activating peptide
14 amino-acid peptide
What are the two components of Acrosome reaction?
- The fusion of acrosomal vesicle with the sperm cell membrane
- The extension of the acrosomal process
In S. purpuratus the acrosomal process contains a protein called
Bindin
It can cause the sperm and egg to fuse in Sea Urchins
Bindin
It restores the diploid chromosome number and sperm centriole became the mitotic spindle
Monospermy
It results in triploid nucleus and multiple mitotic spindles are formed
Polyspermy
What are the processes that could prevent polyspermy?
Fast block to polyspermy
Slow Block to polyspermy
How does the fast block to polyspermy is activated
What is the resting membrane potential that is the difference in charge across the egg membrane
-70mV
It is a slower, mechanical and permanent block to polyspermy
Slow Block to Polyspermy
How does the slow block to polyspermy is activated
It acts as initiator of the cortical granule reaction
Calcium
It is the calcium ionophore that transports calcium ions across lipid membranes
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