Yes. The sign bit of 32-bit integers and of 32-bit floats is set (to one) when the value is negative and clear (to zero) when the value is positive or zero.
The mantissa represents a number in 24-bit base two positional notation that looks like this:
1.xxxxxxxxxxxxxxxxxxxxxxx (x = 0 or 1; there are 23 x's)
Very tricky: The mantissa represents the 23-bit binary fraction part of a 24-bit number that starts with a "1". The 20 place (the one's place) is presumed to contain a 1 and is not present in the mantissa. This trick gives us 24 bits of precision with only 23 bits.
For example, the binary number 1.11110000101101101010001
is represented as 11110000101101101010001