To avoid being degraded by nuclear exonucleases, nascent transcripts, pre-mRNA-processing intermediates, and mature mRNAs in the nucleus must have their ends protected. Which of the following mechanism are present in the cell to protect mRNA from degradation?

I. The 5′ cap is protected because it is bound by a heterodimeric nuclear cap-binding complex (CBC), which protects it from 5′ exonucleases and also functions in export of the mRNA to the cytoplasm.

II. 5’-5’ phosphodiester bond in the cap of mRNA plays crucial role in protection

III. The 3′ end of a nascent transcript lies within the RNA polymerase and is thus inaccessible to exonucleases 

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#Question id: 5639

#Unit 5. Developmental Biology

In a comparison of plant and animal development, it is found that:

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#Question id: 5640

#Unit 5. Developmental Biology

Why has the diploid genome been an advantage in studying the development of arabidopsis?

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#Question id: 5641

#Unit 5. Developmental Biology

The fate map of the arabidopsis embryo at the heart stage indicates that:

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#Question id: 5642

#Unit 5. Developmental Biology

One of the earliest events in arabidopsis development is formation of the _____ axis, in response to a gradient of _____.

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#Question id: 5643

#Unit 5. Developmental Biology

The genetic analysis of arabidopsis development was strongly influenced by genetic analysis of Drosophila development, and as is the case in Drosophila, genes that influence development are often named for:

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#Question id: 5644

#Unit 5. Developmental Biology

If embryos are disaggregated with chemicals or proteases, and the individual cells are mixed together in culture, what will happen?