Pullup resistors on microSD interface

Hi,

In the AM335x Starter Kit schematic (Rev 1.2A, 10th August 2012) there are pullup resistors on the lines DAT0..3 and on the line CMD.
In the AM335x ICE schematic there are pullup resistors on all the lines (also on the CLK line).

Does anyone knows if the pullup resistor on the CLK line is necessary?

Thanks.

Best regards,
Patrick