BIOL131 Midterm Practice Exam Review 1

These flashcards cover the key concepts and questions from the BIOL131 Midterm Practice Exam.

When does fertilization occur in the egg?

It is different depending on the species.

If there was no Ca2+ released by the sperm, which of the following would occur?

No fertilization would occur.

Through what process does the neural plate form?

Neural induction.

What is the depressed area at the center of the primitive streak called?

The primitive groove.

The grey crescent:

Is observable in the frog zygote.

Which process does not contribute to the slow block to polyspermy?

The increase in hydrostatic pressure.

What theory replaced Homunculus and Preformation?

Epigenesis.

Polarity refers to ____ asymmetry whereas differentiation refers to ____ asymmetry.

Intrinsic, created.

If you were to infer where cells differentiated for the brain would arise from, which choice would be correct?

Animal Pole.

Which of the following is false?

Biological systems are capable of breaking the second law of thermodynamics.

Micromeres are responsible for forming the , while macromeres are responsible for forming the ___.

Endoderm, mesoderm.

Which of the following is true?

Organism development occurs through a process called epigenesis, from an unpatterned egg.

Once the neural tube is completely formed, Shh protein is critical for the development of:

Motor neurons.

Which of the following statements about the cleavage pattern of sea urchin embryo is INCORRECT:

The cleavages occur in all of the blastomeres simultaneously even after several divisions.

Which of the following components are not involved in blastocyst formation?

The ectoderm.

In chick blastula formation, which cells migrate from the marginal zone to form the blastodisc?

Epiblast cells.

What is the first coordinated activity that the blastomere of an animal embryo undertakes?

Establishment of polarity.

What kind of protein is Sonic Hedgehog?

Cell signaling molecule.

The cells that form the neural tube come from the:

Ectoderm.

If a mutation in the gene of the bottle cells in the frog gastrula disrupted their function, what would most likely occur?

The blastocoel would not shrink.

Which of the following statements about neurulation is false?

Vesicles at the posterior end of the neural tube become the brain.

During gastrulation in chick embryo, all three parts of the embryo are formed from the ____ with the ____ serving to provide support.

Epiblast, hypoblast.

Which of the following contributes to the lining of the archenteron wall?

Bottle cells.

The cells found on the vegetal pole of a blastocyst are ____ the animal pole.

Larger than.

Which of the following gives rise to the notochord and to the mesoderm?

Henson’s node.

The molecule ____ plays a large role in the development of motor neurons once the ____ is formed.

Shh, neural tube.

If a female sea urchin produces eggs lacking binding receptors, what would most likely occur?

The inability of the normal sperm to fertilize the eggs.

The release of Shh from the notochord leads to…

Gradients of growth factors in the developing neural tube, allowing cell differentiation.

Are somites more prominent in the development of vertebrates or invertebrates?

Vertebrates.

The vertebrate brain develops at the _ end of the neural tube, initially forming ____ brain vesicles.

anterior; three.

The slow block to polyspermy in sea urchins is characterized by:

The separation of the perivitelline layer from the egg.

The ball of 2 or 4 cells formed during cleavage is called:

The blastomere.

The scientific contributions of Ernest Everett included:

Quantifying calcium changes in the sperm.

A major function of gastrulation of vertebrates is to bring the _ under the ectoderm.

Mesoderm, dorsal.

In primary induction, the ectoderm sends signals to the ectoderm to form what?

The neural plate.

Gastrulation in birds includes a thickening called Hensen’s node, which is similar to the dorsal lip of an amphibian blastopore. You would expect to see in this region.

Signaling molecules that organize the developing embryo.

Which of the following characterizes neurulation?

A neural tube forms around the notochord.

The cells that form the neural tube come from where?

Ectoderm.

Which of the following does not occur during cleavage?

Increase in the size of the blastula.

In a typical animal cell, the ions Na+ and Cl- have a(n) _ concentration outside of the cell than inside the cell.

Higher.