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Tuesday, December 28, 2010

Assignment on cell , plants and Drosophila

Assignment # 7 Chapter 11

Write the answers on paper.  (10 pts each numbered question)

1.  Give three genes responsible for cell differentiation in plants.  Specify the function(s) of each gene

2.  Describe the following plant cell communications

a)  through cell walls
            b)through receptors or ligands

3.   What is the importance of polar auxin transport in plants?

4.  Describe the roles of the following hormones in plant development (not growth):
a) abscisic acid
             b) gibberellins
             c) brassinosteroids
             d) ethylene
              e) cytokinnins

5.  Describe the mechanism by which the following function in plants:

a) phytochromes
            b) cryptochromes


Assignment 9.  Chapter 15.  Developmental Regulatory Networks 1

10 pts each.
How are nonequivalent cells in early development generated?  What causes it?
What causes asymmetric division in the early C.  elegans embryo? Describe  the roles of each

What causes  the asymmetric division in the embryonic ectoderm of Drosophila?
What are the genes involved  in establishing the segments in Drosophila?  State how they interact with each other.

What are  the roles of homeotic genes in Drosophila.
Describe the cellular interactions in patterning the wing of Drosophila.


Chapter 3.  Amniote development

1.  What is common in development of reptiles, birds and mammals?  (3pts)

      2.  Describe the changes of the ovulated egg as it passes through to each of the following regions of the bird’s reproductive tract:  (12 pts)
a. infundibulum
b. magnum
c. isthmus
d. uterus

3.  What are the layers of the bird blastodiscs? How is hypoblast formed?  (5pts)

4.  What are the adaptations in bird egg which make it adapted for development in terrestrial habitat?   ( 3 pts)

5.  What is delamination?  (3pts)

6.  Compare and contrast the early development of birds and mammals by presenting them  in the tabular form as below: (20 pts)

7.  What are the mammalian adaptations for the fertilized egg to survive in the mother’s body.  (5 pts)


Assignment # 6 Chapter 10.  Reproduction in Plants

Write the answers on a sheet of paper

1.  Where is id (indeterminate) gene in maize expressed?  What is its role in flowering? (5 pts)

2. What are the genes responsible for switching from IM (inflorescence meristem) to floral meristem?  Give the specific function(s) of each. (5 pts)

3. Describe the expression of floral identity genes designated as ABC genes during flower development. 5 pts

4.  Plants alternate between diploid and haploid generations.  What are these generations? 5pts

5.  What do we call the female gametophyte?  Describe its components. 5pts

6.  What is the male gametophyte?  Describe its components. 5pts

7. Differentiate sexual development with apomixis.  What is the disadvantage of apomictic development? 5pts

10.  What are some genes expressed in the embryo for shoot meristem development?  Give the function of each. 5pts