Mendelian Genetics
Other Patterns of Inheritance + Pedigrees
DNA + RNA
Transcription, Translation, Mutations
Biotechnology
100
A trait is controlled by a dominant allele A and a recessive allele a.
A homozygous dominant individual mates with a homozygous recessive individual.
What percentage of the offspring will be heterozygous?
100%.
100
A black cow mates with a white cow.
Their calf has distinct black and white patches, showing both traits fully and separately.
What pattern of inheritance is shown?
Bonus: What example of this can be seen in humans?
Codominance.
Bonus: Blood types
100
DNA is made of repeating subunits called nucleotides.
Each nucleotide contains three parts that repeat over and over to form the DNA molecule.
What are the three components of a DNA nucleotide?
Phosphate group, deoxyribose sugar, nitrogenous base
100
During transcription, a strand of DNA is used as a template to make messenger RNA (mRNA).
RNA nucleotides pair with DNA bases using complementary base-pairing rules.
If the DNA sequence is A–T–C–G, what is the complementary mRNA sequence?
U–A–G–C
100
Humans have altered organisms for thousands of years by choosing which individuals reproduce based on desired traits. For example, farmers repeatedly breed cows that produce the most milk or dogs with specific sizes and temperaments.
Which biotechnology method is being described?
Selective breeding
200
Albinism is an autosomal recessive condition caused by the inability to produce melanin.
An albino female mates with a male who is heterozygous for the albinism trait.
What percentage of their offspring will show albinism?
50%
200
A white rabbit mates with a black rabbit.
All of the offspring have gray fur, which is a blend of the parents’ traits.
What pattern of inheritance is shown?
Incomplete dominance
200
DNA molecules store large amounts of genetic information in a compact, twisted shape.
This shape is formed by two complementary strands bonded together and twisted around each other.
What is the name of this DNA structure?
Double helix
200
Protein synthesis requires multiple types of RNA working together in the cell.
One type of RNA is responsible for bringing amino acids to the ribosome during translation.
What type of RNA performs this function?
Transfer RNA (tRNA)
200
Scientists insert a human gene into bacteria so the bacteria can produce a useful medical protein.
For example, bacteria can be engineered to produce human clotting factor used to treat hemophilia. Because the bacteria now contain human DNA, they are considered transgenic organisms.
Which biotechnology method is being used to create these transgenic organisms?
Genetic Engineering
300
Cystic fibrosis is an autosomal recessive disorder.
Two parents are phenotypically normal, but both are carriers of the disorder.
What are the possible genotypes of their offspring, and in what percentages?
25% CC
50% Cc
25% cc
300
Human height is influenced by multiple genes rather than a single dominant or recessive allele.
As a result, people show a wide range of heights instead of just a few distinct categories.
What type of inheritance explains this pattern?
Polygenic inheritance
300
The two strands of DNA are held together by hydrogen bonds between complementary nitrogenous bases.
These base-pairing rules allow DNA to be copied accurately.
If one strand of DNA has the sequence A–T–G–C, what is the complementary strand?
T–A–C–G
300
mRNA is read in groups of three nucleotides called codons.
Each codon corresponds to a specific amino acid based on the genetic code.
Using a codon chart, what amino acid is coded for by the mRNA codon AUG?
Methionine (start codon)
300
A research lab wants to produce rats with curly tails, a trait that already exists naturally in some rats.
Which procedure could be used to make sure the offspring have curly tails?
SC.912.L.16.10
A. Selectively breeding rats that already have curly tails
B. Cloning a rat with a curly tail
C. Using genetic engineering to insert a gene associated with curly tails
D. All of the above
D. All of the above
400
Sickle cell anemia is an autosomal recessive condition.
A carrier male mates with a carrier female.
What percentage of their children will be carriers but not affected?
50%
400
A genetic disorder appears only when an individual inherits two recessive alleles.
The trait can skip generations, and males and females are affected at about the same rate.
What type of inheritance is being described.
Autosomal recessive inheritance
400
DNA and RNA are both nucleic acids, but they differ in structure and function.
RNA plays a role in protein synthesis and has structural differences compared to DNA.
Name two structural differences between DNA and RNA.
DNA is double-stranded; RNA is single-stranded
DNA has deoxyribose; RNA has ribose
DNA uses thymine; RNA uses uracil
400
A segment of mRNA originally contains the codon AAA, which codes for the amino acid lysine.
After a mutation, the codon changes to AAG, which also codes for lysine.
Johnny thinks this mutation is silent.
Susy thinks this mutation is nonsense.
Adam thinks this mutation is missense.
Which student is correct, and why?
Johnny is correct because the codon change does not change the amino acid, so the protein remains the same. This is a silent mutation.
400
A transgenic organism contains genetic material from a different species. These organisms are commonly used in medicine and agriculture.
Which statement best describes a transgenic organism?
A. An organism with a naturally occurring mutation
B. An organism produced through selective breeding
C. An organism that contains genes from another species
D. An organism that has been exposed to radiation
C
500
In pea plants, height and seed color are controlled by two different genes.
Tall (T) is dominant over short (t), and green (G) is dominant over yellow (g).
When two plants that are heterozygous for both traits (TtGg × TtGg) are crossed, the phenotypes of the offspring follow a 9 : 3 : 3 : 1 ratio.
Out of 16 plants, how many would be tall and green, and how many would be short and yellow?
9 tall & green
1 short & yellow
500
A family pedigree tracks the inheritance of a genetic disorder across several generations.The trait appears much more frequently in males than in females. When an affected female has children, all of her sons show the trait, but none of her daughters do—unless the father is also affected.
What type of inheritance does this pedigree represent, and what clues support your answer?
X-linked recessive inheritance
More males are affected than females
Affected females always pass the trait to their sons
Females only show the trait if the father is also affected
500
The order of nucleotides in DNA determines the information used to make proteins.
A change in this sequence can change the final protein produced.
Why is the order of nucleotides in DNA important?
It determines the genetic code that specifies which amino acids are made and therefore which protein is produced
500
Certain chemicals and forms of radiation are known to be carcinogenic, meaning they can damage DNA and lead to cancer. Cancer results when normal controls over the cell cycle fail.
Why can damage to DNA caused by carcinogens lead to cancer?
A. Carcinogens directly damage proteins involved in cell division, causing cells to malfunction
B. DNA mutations can change the proteins that regulate cell growth, leading to uncontrolled cell division
C. Carcinogens increase the rate of protein synthesis in all cells
D. DNA damage causes cells to stop making proteins altogether
B
500
Scientists are developing a new drug using genetic engineering. Before the drug can be approved for use in humans, it is repeatedly tested on animals. Some of the animals experience pain or serious side effects during the testing process.
Why does this situation raise an ethical concern in biotechnology?
A. The animals may not produce reliable scientific data
B. Animals are harmed during testing for the benefit of humans
C. Genetic engineering always results in unsafe products
D. The drug may not work the same way in humans