Ch:10 Fertilization and Development Flashcards
Explain what occurs during the acrosomal reaction:
Enzymes punch a “hole” in the jelly while growing actin filaments form from the acrosomal process. Binding to the egg cell receptors occur!!
Explain the process of fast block to polyspermy and compare it to slow block:
Contact and fusion of sperm and egg now occurs. The membrane voltage now changes… Depolarization. This results in what is called the fast block to polyspermy
The Cortical reaction (slow block): Ca++ ions are released from the endoplasmic reticulum. cortical granules in the egg fuse with the plasma membrane. Sperm-binding receptors are removed and a fertilization envelope forms. This forming of the fertilization envelope is termed slow block to polyspermy
(calcium is essential for the cortical rxn to occur)
Continued cleavage gives a solid ball of cells called a ______. From here, a fluid-filled cavity called a ______ forms within this morula and begins to hollow. This hollow ball of cells is now called a ________.
Continued cleavage gives a solid ball of cells called a __Morula__. From here, a fluid-filled cavity called a __blastocoel__ forms within this morula and begins to hollow. This hollow ball of cells is now called a __blastula__.
Put these in chronological order:
- Zygote
- Morula
- Blastula
- Gastrula
Zygote –> Morula –> blastula –> gastrula
After the gastrula is formed a new central cavity is formed called the ________, which will become the primitive gut.
Archenteron
The opening of the archenteron is called the _______. This opening forms the ____ in protostomes and the ____ in deuterostomes.
The opening of the archenteron is called the __blastopore__. This opening forms the mouth in protostomes and the anus in deuterostomes.
Protostomes include: _____, _____, ______
Deuterostomes include: _____, _____
Protostomes include: mollusks, arthropods, annelids
Deuterostomes include: chordates and echinoderms
What allowed arthropods to become successful?
Jointed appendages
Which of the following has a closed circulatory system?
A. Arthropods
B. Annelids
A. Annelids
Grasshoppers use _____(2 words)_____ to aid in metabolic waste removal.
Malpighian tubules
Which of the following is high in yolk?
A. Vegetal pole
B. Animal pole
A. Vegetal pole
In humans, the notochord becomes a ____(2 words)___ found between vertebrae
Gelatinous disk
Tunicates and amphioxus are classified as _______, but are ________.
- Chordates
- invertebrates
Amphibians and frogs are said to have evolved from ____________.
lobe-finned fish
How many heart chambers are in the following:
- Fish
- Reptiles and amphibians
- Birds and mammals
Fish = 2 chambered heart
Reptiles and amphibians = 3 chambered heart
Birds and mammals = 4 chambered hearts
What does the endoderm give rise to?
- Epithelial linings of respiratory, excretory, digestive tracts, urinary bladder, and lining of reproductive systems and urethra
- Glands such as thymus, thyroid and parathyroid
- Liver and pancreas
What does the mesoderm give rise to?
- Bone, muscle, blood, connective tissue, notochord, excretory, lymphatic and excretory system
- Dermis of the skin
- Adrenal cortex
What does the ectoderm give rise to?
- hair, skin, nails, teeth, sweat glands, cornea and lens of the eye and the adrenal medulla
Outtermost layer- most sensitive to radiation!!!
The greatest changes in cell shape and cell position occur in ______ and ______.
Gastrulation and organogenesis
As organogenesis progresses, morphogenesis (think shape) and cell differentiation continue
Condensing of the mesoderm gives rise to the _______. This is a rod of stiffened tissue that serves as a support-like structure in all chordates.
Notochord
Neural plate forms from the ______ and rolls into the neural tube which becomes the central nervous system.
Ectoderm
Somites are formed… they represent block of mesoderm which give rise to _____ and ____.
Vertebrae and muscle
Define all of the following:
- Yolk sac
- Chorion
Yolk sac: encloses the yolk and provides nutrients
Chorion: gas exchange, forms part of the placenta
Define all of the following:
- Amnion
- Allantois
Amnion: absorbs shock and keeps embryo from drying out
Allantois: disposes of nitrogen waste and gas exchange. In humans it does not store wastes, but is involved in O2 and nutrient transport
What is the difference between totipotent and pluripotent cells?
Totipotent is capable of developing into all different cell types (a zygote is totipotent plus the next three cell divisions)
Pluripotent: Think STEM CELLS! capable of developing into many cell types except extraembryonic tissues
Implantation occurs in the _______ of the uterus and occurs before the end of the first week.
Endometrium
The __1__ is what adheres to the endometrium. The __2__ is the mammalian version of a ___3___.
- blastocyst
- blastocyst
- blastula
Human gestation can be divided into three trimesters.
What occurs during the 1st trimester?
- most growth and differentiation occur here
- most sensitive to radiation and drug toxicity
- Main period for organogenesis
- After 8 weeks, the embryo is called a fetus
What is the difference between viviparous and oviparous?
A viviparous development in means the young are born alive after being nourished in the uterus from the placenta
Oviparous means the young hatch from eggs laid outside the mother
Human gestation can be divided into three trimesters.
What occurs during the 2nd trimester?
- all major organs are formed
- pregnancy is now obvious
- corpus lute deteriorates
Human gestation can be divided into three trimesters.
What occurs during the 3rd trimester?
- around 8 months the fetus can survive on its own
What is a homeotic gene?
Homeotic genes are regulatory genes that are responsible for the placement and spacial organization of body parts
