Science question [s] on fossils, and cells?

Question

1. Together respiration and photosynthesis keep the levels of carbon dioxide and oxygen in the atmosphere
a.fairly constant
b.constantly changingc.constantly increasing
d.constantly decreasing

2.How does a bacterial cell differ from a plant or animal cell
a.It is larger
b.It does not have a nucleus
c.It has no cytoplasm
d.It has no organelles
I really didnt know for question 2 if the answer was b. or d. but its not both.

3. What process results in genetically different bacteria?
a.binary fission
b.respiration
c.conjugation
d.asexual reproduction

4.what is the most abundant chemical found in living cells?
a.water
b.carbohydrates
c.protiens
d.nucleic acid

5. The SI unit for mass is the
a.ounce
b.pound
c.kilogram
d.liter

and heres one question about microscopes:
What is the total magnification of a microscope with 2 lenses when 1 lens has a magnfication of 15 and the other lense has one of 30?
you dont have to answer all the questions but please answer all the questions you KNOW

Answer 1

1. A
2. B
3. C
4. C
5. C

Microscopes: Im sure you just multiply the 2 lens magnifications 2gether.

Therefore 15 x 30 = 450 total mignification

Answer 2

1 A. Carbon dioxide and oxygen are taken in and released in the complementary processes of photosynthesis and cellular respiration. (Not considering burning of fossil fuels, methane generation, ...)
2 B. The correct answers ARE actually B and D. Prokaryotic cells have neither nuclei nor membrane-bound organelles. However, the most important one is the nucleus, so I'd pick that one if you have to just choose one.
3 C. Conjugation is a process during which bacteria exchange a segment of the chromsome.
4 A. Water makes up more of the cell than the other choices.
5 C. SI units are metric, so choose kilogram. Liters are units of liquid volume. Ounces and pounds are not metric.

When you look through two lenses at a time, you multiply the magnifications of the lenses. In this case 15*30=_____ which is the total magnification.

Answer 3

1 = a (faily constant)
2 = b (it has no nucleus and no membrane-bound organelles, instead it has nucleoids, ribosomes, etc)
3 = c (one bacterial cell transfers genetic information into an adjoining bacterial cell, creating a genetically different bacteria as opposed to a genetically identical clone)
4 = I think it is a = water (??)
5 = c = kilogram or actually should just be gram.

Answer 4

I do not have the answer to all questions, but I hope this helps. (Do take notice that I might not be right.)
1) a
2) b
3) b or c (a and d are the same)
4) a
5) ?

Answer 5

They coach finished classes in this in universities.....wide books are written in this subject. There are enormous gaps in our comprehend-how. My question for you.....what precisely are you hoping to get with this question?