The table gives the content of glucose, urea and calcium ions in the blood entering the kidney, in
the glomerular filtrate and in the urine of a person.
Values are given in mg per 100 cm'.
Component / mg per 100 cm
Blood Glomerular filtrate
Urine
Component
glucose
100
100
0
urea
26
26
1820
calcium ions
4
4
5
a) i) Which of the components provides energy for
the body?

ii) Which of the components is a metabolic
waste product?

b) Explain why the figures for each component are the
same for the blood concentration and
glomerular filtrale.

When does dna replication(make a copy of itself)?

Consider darwin's first writings on the theory of natural selection. an important point of darwin's essay on the principle of population, written in 1798, was a peer's observation that in nature plants and animals produce far more offspring than can survive, this observation can be attributed to a) charles lyell. b) thomas malthus. c) jean-baptiste lamarck. d) johann friedrich meckel.

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?