Year 13 Biology Worksheet
[March, 2020]
GENETICS
QA.
Name the following:
1. It is the mechanism of inheritance of characters from the parental generation to the
offspring.
2. Differences shown by individual organisms within the same species and in their offspring
is known as this.
3. He is the Father of modern genetics.
4. In a cross involving one pair of contrasting characters, this one character expresses itself
in the next generation.
5. Genotypic ratio in the F2 generation of a monohybrid cross
6. It is a cross involving the F1 hybrid with its recessive parental combination.
7. 9:3:3:1 is the phenotypic ratio in the F2 generation of which type of cross.
8. The chromosome theory of inheritance was proposed by whom?
9. An intragenic interaction where both the alleles of a given trait express as a blend
(mixture) and One allele is not dominant over the other.
10. A Condition where more than two genes occupy the same locus on a pair of homologous
chromosomes.
Consider the following diagram to answer Q11
11. Above diagram shows that Chromosomes can be are distinguished on the basis of the
position of the ------------------------------.
12. The offspring is said to be that trait when it inherits different alleles from both parents.
13. Duplicated chromosome are also called as this.
14. The site where RNA polymerase binds to the DNA and initiates transcription during
Gene regulation.
15. Disorder in which males have an extra X chromosome and the genotype for males with
this disorder is XXY.
16. Disorder in which the individual had 3chromosomes on the 21st pair.
17. Disorder where the person has only one X chromosome on the 23rd pair.
POPULATION GENETICS
1.
The frequency of two alleles in a gene pool is 0.19 (A) and 0.81(a). Assume that the
population is in Hardy-Weinberg equilibrium.
a. Calculate the percentage of heterozygous individuals in the population.
b. Calculate the percentage of homozygous recessives in the population.
2.
An allele W, for white wool, is dominant over allele w, for black wool. In a sample of
900 sheep, 891 are white and 9 are black. Calculate the allelic frequencies within this
population, assuming that the population is in H-W equilibrium.
3.
In a population that is in Hardy-Weinberg equilibrium, the frequency of the recessive
homozygote genotype of a certain trait is 0.09. Calculate the percentage of individuals
homozygous for the dominant allele.
4.
In a population that is in Hardy-Weinberg equilibrium, 38 % of the individuals are
recessive homozygotes for a certain trait. In a population of 14,500, calculate the
percentage of homozygous dominant individuals and heterozygous individuals.
5.
Allele T, for the ability to taste a particular chemical, is dominant over allele t, for the
inability to taste the chemical. Four hundred university students were surveyed and 64
were found to be non tasters. Calculate the percentage of heterozygous students. Assume
that the population is in H-W equilibrium.
REPLICATION
1.
Why does DNA need to replicate?
2.
In relation to the pictures below: Explain three main steps in the process of DNA
replication.
3.
Name the enzymes that go with each step:
4.
In which direction are new nucleotides added during replication
5.
What is the difference between and leading and lagging strand?
6.
Which enzyme is responsible for “unzipping” the DNA double helix?
7.
Which enzyme is responsible for facilitating the hydrogen bonding between nucleotides
in a new DNA molecule?
8.
Which enzyme is responsible for creating the covalent bonds (specifically phosphodiester
bonds) that connect the sugar- phosphate backbone of the new DNA molecules?
9.
Below is a single strand of DNA. Below each letter write the complementary strand of
DNA.
A–T–G–C–G–G–C–G–A–T–T–T–A–A–G–C
10.
a.
In box A below, fill in the complementary strand of DNA to create a
double strand.
b.
Next to the box, using two different colored pens/pencil, create two new strands
from the original strand in the box A. Label which color represents the original
strand and which color represents the new strand.
11.
Describe the origin of each strand of the new double helices created after DNA
replication.
12.
Why do you think DNA replication important to the growth and development of a multi
cellular organism?
13.
What do you think would happen if the process occurred incorrectly?
PROTEIN SYNTHESIS & REPLICATION
Q1
Read the following:
Protein synthesis is the process used by the body to make proteins. The first step of protein
synthesis is called Transcription. It occurs in the nucleus. During transcription, mRNA
transcribes (copies) DNA. DNA is “unzipped” and the mRNA strand copies a strand of DNA.
Once it does this, mRNA leaves the nucleus and goes into the cytoplasm. mRNA will then attach
itself to a ribosome. The strand of mRNA is then read in order to make protein. They are read 3
bases at a time. These bases are called codons. tRNA is the fetching puppy. It brings the amino
acids to the ribosome to help make the protein. The 3 bases on tRNA are called anti-codons.
Remember, amino acids are the building blocks for protein. On the mRNA strand, there are start
and stop codons. Your body knows where to start and stop making certain proteins. Just like
when we read a sentence, we know when to start reading by the capitalized word and when to
stop by the period.
Answer the following questions:
1.
What is the first step of protein synthesis?
2.
What is the second step of protein synthesis?
3.
Where does the first step of protein synthesis occur?
4.
Where does the second step of protein synthesis occur?
5.
Nitrogen bases are read ________ bases at a time.
6.
The bases on the mRNA strand are called ______________________.
7.
The bases on tRNA are called ______________________.
8.
What is the start codon?______________
9.
What are the stop codons? (Use the Genetic Code on p21, Year 13 Biology for All)
10.
A bunch of amino acids attached together is called a _____________________________.
Q2.
Use the Genetic Code (p21 Year 13 - Biology for All) to determine the amino acid
sequence. Remember to read through the strand and ONLY start on AUG and STOP
when it tells you to stop. Follow example below:
1.
DNACCT CTT TAC ACA CGG AGG GTA CGC TAT TCT ATG ATT ACA CGG
TTG CGA TCC ATA ATC
mRNA 
protein 
2.
DNA  AGA ACA TAA TAC CTC TTA ACA CTC TAA AGA CCA GCA CTC CGA
TGA ACT GGA GCA
mRNA 
protein 
3.
DNA  TAC CTT GGG GAA TAT ACA CGC TGG CTT CGA TGA ATC CGT ACG
GTA CTC GCC ATC
mRNA 
protein 
4.
DNA TAA ACT CGG TAC CTA GCT TAG ATC TAA TTA CCC ATC
mRNA 
protein 
5.
DNA CTA TTA CGA TAC TAG AGC GAA TAG AAA CTT ATC ATC
mRNA 
protein 
Q3. Circle the correct choice within the parenthesis.
1. (DNA/RNA) can leave the nucleus.
2. mRNA is made during (transcription/translation).
3. DNA is located in the (nucleus/cytoplasm)
4. (Translation/Transcription) converts DNA into mRNA.
5. (mRNA/rRNA) is used to carry the genetic code from DNA to the ribosomes.
6. (tRNA/rRNA) makes up the ribosome. Look in the book for this.
7. (DNA/RNA) uses uracil instead of thymine.
8. Transcription takes place in the (nucleus/cytoplasm).
9. tRNA is used in (translation/transcription).
10. tRNA uses (anticodons/codons) to match to the mRNA.
11. Proteins are made at the (nucleus/ribosome).
12. (tRNA/mRNA) attaches the amino acids into a chain.
13. tRNA is found in the (nucleus/cytoplasm).
14. (Translation/Transcription) converts mRNA into a protein.
15. Translation takes place in the (cytoplasm/nucleus).
Q4.
Thinking Questions
1. Draw a DNA nucleotide & an RNA nucleotide. Label each of the 3 major parts.
2. What is the point of DNA replication?
3. When & where does replication occur?
4. What is the point of transcription?
5. Where does it occur?
6.What are three nucleotides together called on mRNA? (ie: ACA
7. The mRNA codons can be used in a chart to find ____________.
8. What molecule contains an anti-codon?
9. During what process is it used?
10. Translation takes place in a _____________
11. __________________and ___________________makeup ribosomes.
12. What is the point of translation?
[Source: http://pnhs.psd202.org/documents/rkieft/1514858665.pdf ]
GENETIC VARIATION [Source: https://wordmint.com/public_puzzles/170961]