Year 10 Biological Science Exam Revision
1.
Complete the following table by writing the definition for each term provided.
Inheritance
Trait
DNA
Gene
Chromosome
Allele
Dominant
Recessive
Genotype
Phenotype
Homozygous
Heterozygous
Pure-bred
Hybrid
Autosomal Inheritance
Sex-linked inheritance
Mutation
2.
Complete the Blanks:
Genes and chromosomes are made up of _________________.
There are 23 pairs (46 total) of _________________ in our body
cells. ___________________ carry the code for a single
instruction or protein and determine what an organism looks like
or how it works. Genes which mask the effect of other genes
are called _________________. _________________ are
mistakes in DNA, caused by radiation or carcinogens.
3.
DNA contains 4 nitrogenous bases
a.
The names of these bases are:
A - ____________ T - _________________ C - ________________ G - ______________
4.
b.
What base does A always pair up to or bind with? _____________________
c.
What base does C always pair up to or bind with? _____________________
Complete the table below.
Process
Mitosis
Purpose
Where the process takes
place
Number of daughter cells
produced from parent cell
Are daughter cells haploid
or diploid?
Are daughter cells
identical? Why?
5.
What is the difference between haploid and diploid cells?
Meiosis
6.
7.
8.
9.
For each genotype below, indicate whether it is heterozygous (He) or homozygous (Ho). If
the genotype is homozygous, indicate whether it is dominant (D) or recessive (r).
AA _____
Ee ____
Ii _____
Mm _____
Bb _____
ff ____
Jj _____
nn _____
Cc _____
Gg ____
kk _____
oo _____
DD _____
HH ____
LL _____
Pp _____
For each of the genotypes below determine what phenotypes would be possible.
Purple flowers are dominant to white flowers. Brown eyes are dominant to blue
PP __________________
eyes
Pp __________________
BB ________________
pp __________________
Bb ________________
Round seeds are dominant to wrinkled
bb ________________
seeds.
Bobtails in cats are recessive.
RR __________________
TT _________________
Rr __________________
Tt _________________
rr __________________
tt __________________
For each phenotype below, list the genotypes
Straight hair is dominant to curly.
Pointed heads are dominant to round heads.
____ straight
_____ pointed
____ straight
_____ pointed
____ curly
_____ round
Use the Punnett squares to answer the questions below. Round seeds are dominant to
wrinkled seeds.
Rr x rr
RR x rr
RR x Rr
Rr x Rr
What percentage of the offspring will be
round?
What percentage of the offspring will be
round?
What percentage of the offspring will be
round?
What percentage of the offspring will be
round?
10.
In guinea pigs, the allele for short hair is dominant.
a.
State the genotypes for the following guinea pigs:
i. heterozygous short haired guinea pig
ii. pure-breeding short haired guinea pig
iii. long haired guinea pig have
b.
Show the cross for a pure breeding short haired guinea pig and a long haired guinea
pig.
i. What percentage of the offspring will have short hair?
c.
Show the cross for two heterozygous guinea pigs.
i. What percentage of the offspring will have short hair?
ii. What percentage of the offspring will have long hair?
d.
Two short haired guinea pigs are mated several times. Out of 100 offspring, 25 of
them have long hair. What are the probable genotypes of the parents? Show the
cross to support your answer.
11.
12.
The following is a pedigree for red ears in mice. Shaded individuals show the mice which
have the red-ear characteristic.
a.
Is the inheritance of red ears controlled by a recessive or dominant gene?
b.
What must be the genotype of mouse 8?
c.
What must be the genotype of mouse 12?
d.
What is the probability that the next mouse born to 7 and 8 will have red ears?
Colour blindness is a sex-linked recessive condition. Let B = normal vision, and, b = colour
blindness. Normal vision is dominant.
a.
What is the genotype of individual 1?
b.
What is the genotype of individual 2?
c.
What is the genotype of individual 5?
d.
what is the genotype of individual 12?
e.
if individual 14 mates with a normal male, what is the probability of having:
i.
a child with colour blindness?
ii.
a child who is a carrier for the trait?
13.
14.
Suzanne is married to David and they have four children: Jenny, Julia, Joan and Jacob.
Julia has the X-linked condition haemophilia, but her mum is normal.
a.
Write Julia’s genotype
b.
Write Suzanne’s genotype
c.
Why can’t David be normal?
d.
Jacob has received the recessive gene from his mum. What would be his genotype?
e.
Why can’t Jacob be heterozygous?
f.
What is the probability that the next child born to David and Suzanne is a girl?
g.
What is the chance of having a son with haemophilia?
Explain how mutations can occur.
15.
List the 5 points of Darwin’s Theory of Evolution by completing each statement.
a.
All organisms produce ___________ offspring than can possibly ________________.
b.
In every species there is _______________________.
c.
Nature (___________________ factors) selects which individuals _______________.
d.
The survivors _______________________and pass on their survival ____________.
e.
Each generation is ___________________ because there has been selection of who
survived to _______________. As these changes accumulate, the species
_______________.
16.
Define Natural Selection and explain the meaning behind “Survival of the fittest”.
17.
List 3 “environmental factors” which might contribute to natural selection.
18.
Why is variation important in a population and what might happen to a species with no
variations at all?
19.
Where do new variations originally come from and how does sexual reproduction contribute
to variation?
20.
Explain how one species, which is living in 2 or more isolated groups, might evolve to
become a different species.
21.
Name and describe three pieces of evidence that support the theory of evolution