The Student Room Group

Simple calulation I don't know how to work out. Rep for help

(a) The diameter of the head of a male gamete measures 3mm.

Calculate how many times the diameter of the female gamete is greater than the diameter of the head of the male gamete. Show your working.

Female magnification = x40
Male magnification = x800


The answer is 220-234 but I don't know how to get that! Any help?
Is there a diagram?
Reply 2
RollerBall
Is there a diagram?


Yes but I've typed all the information.
Reply 3
i cant tell you what the answer is becuase you need to measure the size of the gametes on the diagrams to work it out but
magnification = image size / actual size
so maybe you could use the formula to work out the actual size of the female gamete and then divide by male the actual size to see how much bigger it is
hope this helped.
Reply 4
T kay
(a) The diameter of the head of a male gamete measures 3mm.

Calculate how many times the diameter of the female gamete is greater than the diameter of the head of the male gamete. Show your working.

Female magnification = x40
Male magnification = x800


The answer is 220-234 but I don't know how to get that! Any help?


magnification = size of image/actual size of object

so for male, actual size of object = image/magnification (3mm=3000 micrometers/800 to give an actual size of 3.75 micrometers)

The image size of female is not given :confused:
Reply 5
i remember seeing this question, is it aqa? dont you have to measure the female gamete?
you haven't given us enough information. you need to measure the size of the female gamete.
actual sperm size = 0.00000375m
actual egg size = 0.00085125m

egg size in picture = 0.03405m = 34mm


---

Okay, so assuming you've measured the female gamete, and it is 32mm in diameter

you then want to know how big it actually is. because the image is 40x bigger, you divide 34mm by 40

34/40 = 0.8 = size of female gamete in real life

same for male. image is 3mm and 800x bigger.

3/800 = 0.00375

now, how many times bigger is female (0.85) compared to male (0.00375)?

0.00375 x ? = 0.8

0.85/0.00375 = 227

so the egg is 227x the size of the sperm
Reply 8
No wonder I got it wrong! Didn't work out the image size :rolleyes:
Just need to remember the formula.

Thanks everyone.