Biology
How many pairs of chromosomes do humans have?
23 pairs
What is the unit used to measure force?
Newton (N)
A car is travelling at a constant velocity.
What is its acceleration?
0 m/s²
What is the name given to the outermost electron shell?
Valence shell
What is the name of the process by which traits are passed from parents to offspring?
Heredity
A dominant trait is always the most common trait in a population.
False
What is relative atomic mass?
a measure of the average mass of an element's atoms
Which os these is a vector quantity?
A. Distance
B. Speed
C. Velocity
D. Time
Velocity
A student says:
"Electrons can exist anywhere around the nucleus."
Niels Bohr
How many copies of each chromosome do humans normally have in their body cells?
Two copies (one from each parent)
Name the four nitrogenous bases found in DNA?
Adenine, Thymine, Guanine, Cytosine
A DNA strand contains the sequence:
A – T – G – C – C
What would be the complementary DNA sequence?
T – A – C – G – G
A car travels 100 m east and then 100 m west back to its starting point.
What distance did the car travel?
What is its displacement?
200m
0m
What is produced by electron jumping? (When an excited electron falls from a higher shell back to a lower shell)
Light
Three students are discussing chromosomes.
Student A: Genes contain chromosomes.
Student B: Chromosomes contain genes.
Student C: DNA contains chromosomes.
Student B
Name the three components of a nucleotide.
Which genotype is homozygous recessive?
A. AA
B. Aa
C. aa
C
A car accelerates from 10 m/s to 30 m/s in 5 s.
A second car accelerates from 20 m/s to 40 m/s in 5 s.
Which car has the greater acceleration?
Same acceleration
Both change velocity by 20 m/s in 5 s.
Acceleration = 4 m/s².
Three elements have the following electron configurations:
Which element would be the most reactive?
Z
Three students are analysing a distance-time graph.
The graph is a straight diagonal line.
Who is correct?
Student B.
A woman does not have a recessive disorder, but her child does.
What must be true about the mother?
She must be a carrier (heterozygous)
Three forces act on a trolley:
Mass = 10 kg
Calculate the acceleration.
Net force = 40 + 25 − 15
Net force = 50 N
a = F/m
a = 50/10
a = 5 m/s²
A trolley is moving to the right at a constant velocity.
Three students claim:
Student A: "There must be a force acting to the right."
Student B: "The net force is zero."
Student C: "The trolley must be accelerating."
Who is correct?
Student B
An atom has:
What is its:
a) Atomic number?
b) Mass number?
c) Electron configuration?
a) 17
b) 35
c) 2,8,7
Balance:
Fe + O2 → Fe2O3
4Fe + 3O2 → 2Fe2O3