Reproduction & Dev. Biology Flashcards
Binary Fission
Done by what kinds of organisms?
What is the specific structure that separates the cell in this process?
Done by unicellular organisms (prokaryotes and the mitochondria and chloroplasts of eukaryotes)
Septum forms in the middle and separates the cells
Budding
Explain the process
Bud (outgrowth) forms on the organism.
DNA is replicated and deposited into bud, which buds off, eg. hydra, yeast.
Regeneration
Explain process
What organisms use this?
What specific organism?
Piece of organism breaks off, broken fragment regenerate
This is exhibited in hydra & planaria
Fungi are also able to reproduce via regeneration.
Parthenogenesis
Explain process
Unfertilized egg develops
to a viable organism
eg. Honeybees exhibit haplodiploidy (males haploid, females diploid).
Spermiogenesis
Final stage of spermatogenesis
NO genetic material change
Form mature spermatozoa (sperm cells)
Spermatogenesis
Undergo how many meiotic divisions?
How many spermatids at the end?
Formation of mature spermatozoa (n cells) from spermatogonium (2n cells)
Undergo 2 meiotic divisions
4 spermatids
Where is the site of spermatogenesis (sperm production)
Seminiferous tubules of testes
Sertoli cells are activated by what hormone?
What do they produce?
Activated by follicle stimulating hormone (FSH)
Surround and nourish sperm
Produce inhibin (inhibits FSH - negative feedback)
Spermatogenic cells
produce spermatozoa
What’s the mnemonic for the sperm traveling in the body
SEVEN UP
What’s the mnemonic for the sperm traveling in the body
SEVEN UP
Seminiferous tubules → Epididymis → Vas Deferens → Ejaculatory Duct → Urethra → Penis.
Seminal Vesicles
secretes:
fructose (ATP)
viscous mucus
prostaglandins (causes urethral contractions which propels sperm)
Bulbourethral Glands
viscous mucus (cleans and lubricates urethra).
Prostate Gland
alkaline secretions (basic) to counteract uterine acidity
What are the 3 accessory glands?
Seminal Vesicles
Prostate Gland
Bulbourethral Glands
Epidymis
What does this structure allow sperm to do?
Maturation and storage
Sperm Structure?
Head: contains nucleus & acrosome
Midpiece: mitochondria (ATP)
Tail: long flagellum (microtubules) to propel sperm.
What does FSH do in MALES?
What does FSH do in FEMALES?
MALES: sperm development in SF tubules w/ help of Sertoli cells (looks like FiSH!!!)
FEMALES: follicles in the ovary to develop Females Sex Hormones
What does Lutenizing Hormone do in MALES?
In FEMALES?
MALES: stimulates Ley-(BIG)dig cells to produce testosterone (make men BIG)
FEMALES: OVULATION & corpus luteum formation
Blastocyst is what?
Fertilized egg
Uterus 3 layers?
Perimetrium (outer)
Myometrium (middle, smooth muscle)
Endometrium (inner epithelial, lined by mucous membranes).
Oogenesis
Produces oogonia
Which part of the female anatomy is responsible for producing eggs?
Ovary
What is the name of the structure that is found between the uterus and the vagina?
Cervix
In which phase of the first meiotic division will primary oocytes be arrested, and when will they resume dividing?
Prophase 1, puberty
AFTER birth cells are also arrested here
In which phase of the second meiotic division will secondary oocytes be arrested, and when will they resume dividing?
Metaphase 2, fertilization
The follicle produces female sex hormones, what are they?
Progesterone and Estrogen
The corpus luteum is maintained by ____ and _____ levels.
FSH and LH
A surge in LH causes _____ of an egg and formation of the _____ _____.
ovulation, corpus luteum
Order of zygote development
Zygote, cleavage, morula, blastocyst, implantation
If implantation DOES occur, then placenta makes what hormone??
Human Chorionic Gonadotropin (HcG)
Fertilization
What is the order of fertilization?
Capacitation
Acrosomal Reaction
Fast Black
Slow Block (Cortical reaction)
What do the hydrolytic enzymes released from the sperm during the acrosomal reaction do?
‘chewing’ through the zona pellucida, this allows the sperm to fuse with the egg’s plasma membrane
During gastrulation, what is the structure that can be found in very primitive organisms?
The gut tube
What happens at the end of the luteal phase?
Estrogen and Progesterone levels fall (no implantation)
They rise IF there IS implantation
What molecule is increased during capacitation? What does this prepare?
Prepares the tip of the sperm for acrosomal rxn
Increases the permeability to calcium
What happens during the acrosomal reaction?
Sperm goes through corona radiata to reach zona pellucida
-actin binds to zona pellucida 3 protein
Sperm head and acrosome fuse -> acrosomal enzymes -> sperm & egg fused
Where does the egg that will be ovulated get released from? Where does the egg attach to?
Graafian follicle!
Attaches to fimbriae
this follice used to be a small one on the ovary and developed the most to be dominant!
Explain what the fast block for sperm is!
Sodium ions diffuse into cells & depolarize, happens in seconds
Explain what the slow block for sperm is!
Calcium ions stimulate cortical granules which make barrier and release zona pellucida from egg, takes a bit to happen
Lactation (suckling) increases what hormones?
PRLactin production which causes lactation
Oxytocin releases milk (milk let down reflex).
Oxytocin increase stimulates what to happen?
Induces contractions which push the baby out of the womb
Difference between radial and spiral cleavage?
Radial Cleavage: cleave down the middle
Spiral Cleavage: cleave down a deviated axis
Difference between determinant and indeterminant cleavage?
Determinate (Mosaic) Cleavage: blastomeres have pre-set fate!!!
Indeterminate (Regulative): blastomeres do not have pre-set fate (totipotent)
Difference between holoblastic and meroblastic ? What’s the 1 exception?
Holoblastic: use entire egg to cleave
- happens in animals with little yolk (humans)
Meroblastic: use part of the egg to cleave
- happens in animals with lots of yolk (birds, reptiles, fish)
FROGS are the exception (holoblastic but lots of yolk)
What is the blastula? What does it differentiate into?
Hollow cavity (has blastocoel)
Trophoblast and ICM
Trophoblast
forms what?
produces what?
-forms chorion
-implants embryo in uterus
-produces HCG
Inner Cell Mass
forms what?
differentiates into what?
- forms embryo
- forms 3 other extraembryonic membranes (amnion, yolk sac and allantois)
- differentiates into epiblast and hypoblast
Which one is essential for gastrulation? Epi or hypoblast? Why?
Epiblast because it creates the primitive streak
What are the 3 layers of the gastrula? What is the gastrula?
Trilaminar embryo
Ectoderm (Attractoderm)
Endoderm (Endternal derm)
Mesoderm (Movement derm)
Ectoderm (Attractoderm) organs!
Adrenal medulla
Enamel of the teeth
CNS/PNS
Sensory of eye, ears & nose
Sweat glands
Pigmentation cells
Endoderm (Endternal derm) organs!
Epithelial lining of digestive, respiratory, & excretory sys.
(PLTT)
Pancreas
Liver
Thyroid/Parathyroid
Thymus
Mesoderm (Movement derm) organs!
Gonads
Cardiovasc. sys
Muscle/Bones
Adrenal cortex
Spleen
Kidneys
Notochord!!!!
Order of nervous system formation
Notochord>Neural plate>Neural fold>Neural tube>CNS
Neurulation?
Development of a nervous system
Monozygotic twins
identical twins
One zygote splits. Two embryos with identical genetic material.
Dizygotic twins
fraternal twins.
Two separate eggs fertilized by two separate sperms. Two zygotes with different genetic material.
List the structures outside of the embryo. What is the outmost and innermost?
Chorion (outer) , yolk sac, amnion (innermost), allantois
Fertilization occurs in the _____
oviduct (fallopian tube)
Oviparity
Offspring develop and hatch outside of the mother’s body. Birds, fish, and reptiles are oviparous
Viviparity
Offspring develops inside the mother’s body, birth follows. Most mammals are viviparous.
Ovoviviparity
Hybrid between oviparity and viviparity. Offspring develop and are hatched within the mother’s body. Some snakes and amphibians are ovoviviparous.
Chorion
gas exchange
Placental Animals: platform for waste, nutrient, gas exchange, forms placenta
Egg Laying Animals: membrane for gas exchange under eggshell
Yolk Sack
Placental Animals: short period of function, makes first blood cells
Egg Laying Animals: houses all the nutrients for embryo development
Amnion
innermost layer, secretes amniotic fluid to protect embryo (embryo sits here)
- amphibians & fish do not have an amnion!!!
Allantois
waste disposal sac, buds off the archenteron
Placental Animals: transports waste to placenta, becomes umbilical cord, then
urinary bladder as an adult
Egg Laying Animals: stores uric acid then fuses with chorion to help w/ gas exchange
What extra embryonic structure becomes the urinary bladder in humans/placental animals?
The allantois
Increasing progesterone and estrogen causes the levels of _____ and ___ to drop
FSH and LH
Within the corona radiata, there is a layer of glycoproteins called the _____ layer that surrounds the plasma membrane of the egg.
vitelline
The outermost layer of the egg of a mammal is called the____ _____
corona radiata.
During which stage of embryonic development are three germ layers formed?
Gastrulation
The endometrium ______ when progesterone and estrogen are _____ during the luteal phase of the menstrual cycle.
thickens, high
The beginning of the menstrual cycle is marked by _____ estrogen and progesterone.
low
Deuterosomes form what structure first?
(think when u take a deuce)
Anus forms first, then mouth
Protosomes form what structure first?
Mouth first then anus
The notochord does not develop into the neural tube; it simply _____ the formation of the neural tube from ectodermal cells.
induces
Laminin does what?
helps cells to receive signals. It can influence cell movement but does not physically aid in that movement.
Eukaryotic flagella are composed of microtubules, which are made up of _____ protein dimers
tubulin
Which is first, fast or slow polyspermy block?
Fast is first
