At what stage does a sperm first acquire motility?

Looking at the image of a cross section through a developing embryo below: 

What names are given to, and what derivatives are formed by the structures labelled E?  Select all options that apply. 

Which of the following events is the first to occur after fertilisation?

Choose the CORRECT option below:

You are a researcher working on understanding development of cartilage. Which of the following would be appropriate organisms to model this process? More than one may be chosen. 

Which of the following is a function of intermediate filaments?

Cell death can be initiated in a cell by a number of factors.  Which of the following would be more likely to result in necrosis rather than apoptosis?

What type of specialisations might you find on the apical surface (facing the lumen) of a simple columnar epithelium?

In the image below, how would you describe the location of the vertebrae (near label E) in comparison to the intestines (label B)?  

At which part of the female reproductive tract would a sperm and oocyte interact in order to maximise the likelihood of a successful pregnancy?

You are a researcher working on understanding development of the vertebrae. Which of the following would be appropriate organisms to model this process? More than one may be chosen.