Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

35 Cards in this Set

  • Front
  • Back
What is the union of male and female gametes to form a zygote?
What is the zona pellucida?
A layer of glycoprotein between the granulosa cells and egg's plasma membrane that the sperm have to use their acrosomes to penetrate.
What happens as soon as a sperm fertilizes an egg?
Chromosomes in the egg complete their second meiotic division, cytoplasm moves forming a gray crescent, and protein sythesis increases.
What is the ball of cells that results from from cleavage called? What is each cell called?
A morula. A blastomere.
What is formed when the morula becomes hollow? What is the cavity that is formed called?
The blastula. Blastocoel.
What is holoblastic cleavage?
Cleavage occuring throughout the egg resulting in a symmetrical blastula with equal sized cells. Occurs in eggs with little or no yolk.
Organisms without holoblastic cleavage have animal and vegetal poles on the blastula. Which one has more yolk?
The vegetal pole.
What is meroblastic cleavage?
A form of embryonic development with a dividing blastodisc sitting on top of a yolk.
What is a trophoblast?
The outer layers of cells on a mammalian blastula (blastocyst).
Besides the fetus's trophoblast, what else is the placenta made of?
The decidua basilis.
What are the three embryonic axes?
Anterior-posterior, dorsal-ventral, and proximal-distal.
Why are are biologists interested in embryonic stem cells?
They could potentially differentiate into any tissue cell and can be useful medically.
What do cells do during gastrulation?
Invaginate (dent inward) and involute (roll inward).
What are the three germ layers?
Ectoderm (epidermis and nervous system), Mesoderm (internal organs), and Endoderm (digestive tract).
What is the blastopore? What is the archenteron? How are they formed?
The hole leading inward the later becomes the anus. The cavity that later becomes the digestive tube. Gastrulation.
What is a primitive streak?
A furrow on the embryo of a reptile, bird, or mammal that forms during gastrulation.
In chordates, how does the process of tissue differentiation begin? What is this process called?
The formation of the notochord and hollow dorsal nerve cord. Formation of the nerve cord is called neurulation.
The ends of the _______ ____ come together to make the _______ _____ which later forms the central nervous system.
Neural groove, Neural tube
After notochord formation, the mesoderm forms series of segmented blocks called ________ which are further distinguished into ________. What do these things do?
Somitomeres, somites. They develop into muscles, vertebrae, and connective tissues.
What is the neural crest? What are placodes?
The strip of cells formed as the neural groove pinches in the form the neural tube that develops into many organs characteristic of chordates. Ectodermal cells near the neural crest that later for the head's sense organs.
What are organizers?
Cells in the embryo that secrete chemicals that diffuse and convey location to other cells.
What is induction? What is primary induction? Secondary induction?
The process of some cells causing neighboring cells to differentiate into new tissues. Induction between the three germ tissues. Induction between nongerm tissues.
What is the essence of embryonic cell development?
The progressive restriction of gene expression.
What is a determined cell? What is the process of a cell becoming determined?
A cell who's developmental fate is decided. Commitment.
What is meant by "Ontogeny recapitulates phylogeny"?
The embryonic development of organisms often reflects the embryonic development of its evolutionary ancestors.
What are extraembryonic membranes? What do they later become? What are some of the extraembryonic membranes?
Membranes that are derived from the embryo's cells but are located outside the body. Fetal membranes. The amnion, chorion, yolk sac, and allantois.
What do the amnion, chorion, yolk sac, and allantois do?
The amnion surrounds the embryo, the chorion surrounds all of the other membranes, the yolk sac stores food, and the allantois stores waste.
What is implantation?
The process of the blastocyst digesting its way into the endometrial lining of the mother.
What are the two parts of the placenta?
The chorionic frondosum (from fetal cells) and the decidua basalis (from maternal cells).
What is morphogenesis?
The development of the embryo's shape during the first trimester.
What is development like in the first trimester? Second trimester? Third trimester?
Organs and body shape form. Bones grow. The entire body grows.
What is lanugo?
Fine hair that grows on the embryo in the second trimester.
What hormones cause uterine contractions during labor?
Prostaglandins and oxytocin.
What hormone causes the development of mammary alveoli? Alveolar ducts? Production of milk? Release of milk?
Progesterone. Estradiol. Prolactin. Oxytocin.
What is allometric growth?
The growth of different parts of the body at different rates.