Biology for nursing entrance exams worksheet with answers

What is natural selection?

1. AOrganisms changing their genes when they need to
2. BIndividuals with helpful traits survive and reproduce more
3. CAnimals choosing which mates they like best, so traits change at random
4. DHumans breeding plants for useful traits

What is the main material in the cell wall of bacteria?

1. APeptidoglycan
2. BCellulose
3. CChitin
4. DKeratin

In science, what is an observation?

1. AA conclusion drawn before any data are collected
2. BA rule that explains all known facts
3. CInformation gathered with the senses or instruments
4. DA guess about why something happens

A red blood cell is placed in a very salty (hypertonic) solution. What happens?

1. AWater leaves the cell and it shrinks
2. BNothing changes because salt cannot cross
3. CSalt enters the cell and it swells
4. DWater enters the cell and it bursts

Why are G–C base pairs held together more strongly than A–T pairs?

1. AG–C pairs form three hydrogen bonds, and A–T pairs form two
2. BG–C pairs are joined by strong covalent bonds instead of hydrogen bonds
3. CG and C are both purines, so they fit more tightly
4. DA–T pairs are found only in RNA

What does "diploid" mean?

1. AThe cell has one set of chromosomes
2. BThe cell has two sets of chromosomes
3. CThe cell has no nucleus
4. DThe cell can divide only once

In a drug trial, one group receives a sugar pill that looks like the real drug. Why?

1. ATo increase the dose of the real drug
2. BTo control for the placebo effect, the improvement caused by expecting treatment
3. CTo make sure every patient is cured
4. DTo save money on the real drug

Which evidence supports the theory that mitochondria came from bacteria that lived inside an ancient cell?

1. AThey have their own circular DNA, ribosomes and a double membrane
2. BThey are found in all prokaryotic cells
3. CThey have a cell wall made of peptidoglycan
4. DThey make the proteins used by the whole cell, including the nucleus