Sperms bind to the zona pellucida and release the contents of their acrosome. Its enzymes then begin to digest the zona pellucida.
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What happens in the penetration of the egg membrane?
The acrosome rxn exposes an area on the sperm that has proteins that allow it to bind to the egg. The first sperm whose nucleus enters the ovum fertilizes it.
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What happens in the cortical reaction?
Activated by egg penetration. Cortical granules empty out their enzymes, which digest other sperms' binding proteins so no other sperm can bind, and they make the zona pellucida harden.
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What are the products of oogenesis related to function?
Egg has to provide for start of growth and development of early embryo.
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What are the products of oogenesis related to size?
Egg is much larger due to its 2 meiosis divisions creating a much smaller polar body which dies, so more cytoplasm for egg.
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What are the products of oogenesis related to production?
Eggs formed once per menstrual cycle
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What are the products of spermatogenesis related to function?
Sperm must have haploid nucleus, flagellum, method of entering egg (acrosome rxn)
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What are the products of spermatogenesis related to size?
Much smaller as for each meiosis 4 spermatids produced, less cytoplasm.
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What are the products of spermatogenesis related to production?
Produced constantly by testes after puberty, approx 1 mill present at any time
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How does the placenta allow exchange of materials?
Placental barrier is selectively permeable, separates the fetal blood around the placental villus capillaries, and the mother's blood around the capillary.
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What is the first step of the malphigian tubule system?
Cells lining the outside of the Malphigian tubules actively transport ions and uric acid from the hemolymph into the tubules' lumens
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What is the second step of the malphigian tubule system?
Tubules empty into gut
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What is the third step of the malphigian tubule system?
In the hindgut water and salts are reabsorbed. Nitrogenous waste excreted within feces.
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How does the convoluted tubule reabsorb sodium ions?
Moved out of filtrate to the outside of tubule by pump proteins' active transport. They then diffuse to peritubular capillaries.
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How does the convoluted tubule reabsorb chloride ions?
Na+ active transport creates charge transport so Cl- ions attracted from filtrate to space outside tubule.
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How does the convoluted tubule reabsorb glucose?
Co-transporter proteins co-transport glucose to outside of tubule. When the Na+ ions diffuse, energy is provided for the glucose to move at the same time to fluid outside the tubule.
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How does the convoluted tubule reabsorb water?
Pumping solutes out of filtrate creates an osmotic gradient so water is reabsorbed by osmosis.
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What is the first step of the loop of Henlé creating hypertonic conditions in the medulla?
Active transport of wall cells in AL pump Na+ ions (200mOsm) into the interstitial fluid, which is now hypertonic to interstitial fluid (500mOsm)
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What is the second step of the loop of Henlé creating hypertonic conditions in the medulla?
Fluid moves down DL. Water moves out by osmosis into interstitial fluid. Now filtrate and fluid are isotonic.
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What is the third step of the loop of Henlé creating hypertonic conditions in the medulla?
Step 1 repeated. Interstitial fluid conc. raised to 700mOsm. Filtrate in descending limb becomes isotonic. Max 1,200mOsm.
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What is the first step in decreasing high blood solute concentration?
Hypothalamus signals to pituitary gland to secrete ADH
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What is the second step in decreasing high blood solute concentration?
ADH makes walls of distal convoluted tubule and collecting duct more water permeable. Now water is reabsorbed via osmosis (high medulla conc)
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What is the final result of ADH secretion?
Small volume of urine with high solute conc released, solute conc of blood decreases.
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What are the roles of hormones during parturition?
What happens in the penetration of the egg membrane?
Back
The acrosome rxn exposes an area on the sperm that has proteins that allow it to bind to the egg. The first sperm whose nucleus enters the ovum fertilizes it.
Card 3
Front
What happens in the cortical reaction?
Back
Card 4
Front
What are the products of oogenesis related to function?
Back
Card 5
Front
What are the products of oogenesis related to size?
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