#Question id: 7766
#Unit 5. Developmental Biology
The relationship between shortened telomeres and stem cell
depletion has been seen in degenerative diseases such as mouse muscular
dystrophy,
I) When____ is activated by damaged telomeres, DNA replication halts, and if the repair doesn’t work, apoptosis is initiated. If the cell is a stem cell or some other rapidly replicating cell, this will reduce the numbers of cells produced, and the lack of stem cells will produce an “aged” phenotype.
#Question id: 7767
#Unit 5. Developmental Biology
How can evolution select for phenotypes that postpone reproduction or sexual maturity?” There is often a trade-off between reproduction and maintenance, and in many species reproduction and senescence are closely linked. Recent studies of mice, Caenorhabditis elegans, and Drosophila suggest that there is a conserved genetic pathway that regulates aging and that it can indeed be selected for. This pathway involves the response to insulin and insulin-like growth factors, Name of these transcription factors are
#Question id: 7768
#Unit 5. Developmental Biology
The insulin signaling pathway inhibits the synthesis of the Foxo transcription factor proteins that would otherwise increase cellular longevity. Downregulation of the insulin signaling pathway has several other functions, choose right one
#Question id: 7305
#Unit 5. Developmental Biology
In plants, a growing mass of unorganized and undifferentiated cells that cover a wound; these cells can be induced to form a plant meristem and develop into shoots and/or roots called as
#Question id: 5647
#Unit 5. Developmental Biology
Use the following information to answer the question. In order to test how sea urchin sperm bind to eggs, scientists isolated the egg receptor protein
that binds to the sperm acrosomal protein called bindin. Plastic beads were coated with egg receptor for bindin (ERB1) from eggs of the sea urchin Strongylocentrotus purpuratus, and then the beads mixed with sperm from S. purpuratus or from the related species, S. franciscanus. The researchers counted how many sperm were bound to each bead. The results are shown in the graph below. Treatments:
A: S. purpuratus sperm mixed with S. purpuratus ERB1 beads
B: S. purpuratus sperm mixed with beads containing no ERB1 protein
C: S. franciscanus sperm mixed with S. purpuratus ERB1 beads
D: S. franciscanus sperm mixed with beads containing no ERB1 protein
Based on the data in the graph, which of the following conclusions is supported?
#Question id: 7751
#Unit 5. Developmental Biology