Atomic Structure
How many electrons has Mg2+ lost?
Two
Vitamin C is an acid. What will happen if you put blue litmus in it?
It will turn red.
How can a mutation pass to the next generation?
Only through gametes
What is a mutation?
A permanent change in the DNA
Which exerts more pressure, a high heel or a snow shoe?
The high heel. (P=F/A and heels have a very small area)
What is the electron configuration of sulfur (atomic number 16)?
2,8,6
Vitamin B6 is a base. What will you observe if you add it to calcium carbonate?
Nothing happens
What is the expected phenotype ratio in the offspring of two heterozygous individuals?
3:1
Is height in humans determined by genetics, environment or both?
Both - genetic potential for height can be altered by environmental factors e.g. malnutrition, growth hormone exposure
What is the force on a 5kg cat accelerating at 2ms-2?
F = ma
F = 5 x 2
F = 10N
Chlorine has 17 protons. How many protons in chloride Cl-?
17
What will happen if you use hot vinegar rather than cold vinegar when making a baking soda and vinegar rocket?
It will react faster (go higher)
A Punnett square predicts that half of parents' offspring will be male and half female. How can a family have five female and no male offspring?
Every fertilisation is random 50:50 chance. Previous offspring have no influence on likelihood of later siblings being male or female.
What is the advantage of having variation in a population?
If there is a change in environment, some may survive to pass on successful genes to future generations.
Describe the net force on a car that is braking.
Net force is backwards, friction is greater than thrust. (but motion is still forwards)
Balance this equation:
HCl + Na2CO3 -> NaCl + CO2 + H2O
2HCl + Na2CO3 -> 2NaCl + CO2 + H2O
In a graph showing the rate of reaction between acid and either powdered base or lumps of base, why do both lines finish at the same point?
They started with the same amount of reactants.
Two brown bunnies have two brown and two white offspring. Explain why this proves white colouring is recessive.
Parents must be heterozygous - their dominant allele gives them a brown coat but they each carry a hidden white allele. Their white offspring got a recessive allele from each parent.
It can't be dominant because that would make parents homozygous recessive, and they wouldn't have any white alleles to pass to their offspring.
Birds with longer beaks were more likely to survive a drought than short beaked birds. What is the likely outcome for this population if drought conditions continue?
Long beaked bird will be more successful in surviving and breeding and will pass on long beak alleles to their offspring. Short beaked birds will be less likely to survive and reproduce, passing on no genes. The population will show an increasing frequency of long beaks each generation.
Define mass and weight.
Mass is the amount of matter in an object. Weight is the force of gravity acting on a mass (F=ma)
Why is the ratio of copper ions (Cu2+) different in Cu(OH)2 and CuCO3?
Cu(OH)2 is 1Cu2+:2OH-. Two hydroxides each need to take an electron from copper to make an overall balanced charge (2+ and two -). One carbonate takes two electrons from one copper so they are balanced in a 1:1 ratio to have no overall charge (2+ and 2-).
Use collision theory to explain why adding water to vinegar when making a baking soda and vinegar volcano makes the reaction go more slowly.
Adding water makes the vinegar more dilute so there are fewer active particles of acid to collide with baking soda so the frequency of successful collisions is lower, decreasing the rate of the reaction.
Using the terms DNA, mutation, gene, allele, phenotype, explain how a mutation in a gene can cause albinism (can't make melanin to colour skin and hair).
A mutation in the DNA sequence that codes for the gene to make melanin could change the protein created. This altered sequence would be a different allele for the melanin gene. The phenotype produced would be white hair and skin because the melanin protein is different because of the different DNA sequence.
How does sexual reproduction result in variation in beak length of a bird species? Include the processes of gamete formation and fertilisation.
Sexual reproduction is two parents creating a unique offspring from two gametes.
Meiosis is gamete formation. Independent assortment (random lining up on equator in homologous pairs) and crossing over (swapping DNA between homologous pairs) shuffles the parental DNA to make unique gametes with half the number of chromosomes.
It is random which sperm meets which egg in fertilisation, combining DNA from both parents. Offspring therefore show variation. Beak length will depend on which alleles for beak length were inherited from each parent.
Why is final Ek usually less than initial Ep of a falling object?
Some energy is lost as heat through friction (watch out for hints in the question: "assume no losses")