BIOL303 Study Guide - Final Guide: Lampbrush Chromosome, Germinal Disc, Blastoderm

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goldplatypus543

3 Oct 2017

School

University of Waterloo

Department

Biology

Course

BIOL303

Professor

Bruce Reed

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Document Summary

The lampbrush chromosome is a special type of chromosome found in the growing oocytes of most animals except for mammals. The blastodisc is the non-yolky cytoplasm located at the animal pole that results from pronounced cytoplasmic streaming following fertilization. This is where discoidal meroblastic cleavage divisions will occur. Epiboly is most prominently associated with gastrulation the fish embryo: sketch and label the fish embryo as it initiates gastrulation. The embryonic shield is responsible for the induction of ectoderm to become neural tissue instead of epidermis. This involves the inhibition of bmp, wnt, and nodal signaling. The developing notochord secretes factors (bmp antagonists) to block the induction which allows ectoderm to become neural. Chordamesoderm secretes chordino (similar to chordin in amphiabians) and inactivates bmp28. Nuclei of the yolk syncytial layer beneath cells that will become the embryonic shield accumulate b-catenin. B- catenin forms transcription factor with tcf3 to activate mesoderm patterning genes (squint and.

Related Questions

Please briefly explain reasoning for all questions.

Which of the following is a component of a vertebrate kidney? (Select all correct choices.)

	glomerulus
	Bowman's capsule
	renal tubules
	collecting ducts
	Malphigian tubules

In organisms, the ability to control osmosis depends on the properties of the plasma membranes of individual cells. Based on their ability to permit the free movement of water and some solutes, these membranes are best described as: (select all correct choices)

	impermeable.
	permeable.
	semipermeable.
	diffusible.
	impervious.

True or false: The inner cell mass of the blastocyst becomes the embryo, while the outer cell layer of the blastocyst forms part of the placenta.

	true
	false

Which of the following accurately characterizes the early cleavage divisions in most animals, although not necessarily in mammals?

	They do not involve an increase in the size of the zygote.
	They are directed by the zygoteâs genome.
	They are relatively slow.
	They do not occur at the same time, so at any given moment the zygote may have an odd number of cells.
	All of these choices are correct.

A key difference between hormonal regulation of the reproductive systems of males and females is that:

	LH and FSH are released only in females.
	LH and FSH are released only in males.
	LH and FSH are released cyclically in females but nearly continuously in males.
	LH is released in males and FSH is released in females.
	LH is released continuously in males and FSH is released cyclically in females.

Compared to sexual reproduction, asexual reproduction: (select all correct choices)

	requires less investment in attracting mates.
	allows much more rapid population growth.
	is rarely found as the sole mechanism of reproduction.
	results in the production of genetically identical cells or individuals.
	involves meiosis and fertilization as core processes.

True or false: In response to LH and FSH, ovaries secrete estrogen and progesterone.

	true
	false

During the luteal phase of the menstrual cycle, if the oocyte is not fertilized, a number of events occur which are listed below. Select the answer that places the events in the correct chronological order.

Events:
1. the lining of the uterus is shed
2. the corpus luteum secretes progesterone
3. follicle cells are converted to the corpus luteum
4. the corpus luteum degenerates
5. estrogen and progesterone levels fall

	3, 2, 4, 5, 1
	1, 2, 3, 4, 5
	2, 4, 3, 1, 5
	4, 3, 2, 1, 5
	5, 2, 3, 4, 1

If an antibody is missing its Fc fragment, what would happen if this antibody encounters its target antigen in the bloodstream? Select all correct choices.

	The antibody would be able to bind the antigen at a specific epitope.
	The antibody would be able to bind the antigen, but not at an epitope site.
	The antibody would not be able to bind to the antigen.
	The antibody would be able to activate components of the complement system.
	The antibody would not be able to activate components of the complement system.

10)

If an individual carries a mutation that results in a complete lack of MHC class I proteins, how would the individualâs immune response be affected? Select all correct choices.

	Memory cell antibodies would not be able to attach to antigen epitopes.
	Cytotoxic T cells would not be able to target (and destroy) infected cells.
	Helper T cells would not be able to interact with antigen-presenting cells.
	Plasma cell antibodies would not be able to attach to antigen epitopes.

11)

If an individual carries a mutation that results in a complete lack of MHC class I proteins, how would the individualâs immune response be affected? Select all correct choices.

	Memory cell antibodies would not be able to attach to antigen epitopes.
	Cytotoxic T cells would not be able to target (and destroy) infected cells.
	Helper T cells would not be able to interact with antigen-presenting cells.
	Plasma cell antibodies would not be able to attach to antigen epitopes.

12)

Which of the following statements is true regarding T cell receptors? Select all correct choices.

	They recognize antigen-MHC complexes.
	They contain variable and constant regions.
	They are composed of two heavy (H) chains and two light (L) chains.
	They are formed by the rearrangement of V, J, C, and D gene segments.
	They can be found in the bloodstream independent of T cells.

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BIOL303 Study Guide - Final Guide: Lampbrush Chromosome, Germinal Disc, Blastoderm

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