Genetics Vocabulary and Concepts
This is a segment of DNA on the chromosome that is coded for a particular trait.
Gene
What tool is used to predict the possible genetic outcomes of a cross between two parents?
Punnett Square
Which Mendelian law explains why allele pairs separate during the formation of gametes?
The Law of Segregation states that each organism has two alleles for each gene, and these alleles separate during meiosis so that each gamete (sperm or egg) receives only one allele.
What would the complementary strand of DNA be for the sequence of bases ACCTAGTTG?
TGGATCAAC
What is the process of making RNA from DNA called?
Transcription
This is an observable trait of an organism that can mask the recessive trait.
Dominant trait
Complete a Punnett square for the cross Bb × bb and identify the genotypic ratio.
Bb Bb
bb bb
50% heterozygous
50% homozygous recessive
Freckles are a dominant trait in humans. Both of these girls have lots of freckles. Their mother has freckles but their father does not. What is the MOST LIKELY genotype that produces the two girls' freckles?
Ff
DNA is a double helix which means that it is shaped like a __________
spiral staircase or twisted ladder
Why are proteins important to cells?
Proteins perform functions that determine traits and cell activities.
Changes in the DNA sequence that affect the expression of genetic information are called
mutations
A strange disorder causing fingers to sprout out of one’s face is discovered to be dominant. A heterozygous female marries a heterozygous male. What percentage of the offspring will have fingers sprouting out of their face?
75%
R = red flowers
r = white flowers
According to Mendel’s law of dominance, which genotype(s) represent offspring with red flowers?
RR and/or Rr
Why is the sequence of nitrogen bases important?
It determines the genetic code used to make proteins.
What part of a nucleotide is responsible for the coding of specific proteins and traits?
The base/ base pair
A specific characteristic that varies from one individual to another
Trait
Most white-tailed deer have reddish brown fur, but occasionally a deer may be born with a genetic condition known as albinism which results in white fur. Albinism is caused by the inheritance of two recessive alleles for the production of coloration pigments. If an albino deer is born to two parents who each have normal fur coloration, what conclusion may be drawn about the genotypes of the parent deer?
Both parents must be heterozygous for the coloration gene.
A black cat and an orange cat mate. In the litter of kittens, all are orange and black calico mixed. What type of inheritance is this an example of?
codominance
According to Chargraff’s rules, if you have 23% of the base Cytosine in DNA, how much Thymine would be present?
27%
Once the DNA strand is transcribed, the mRNA strand is sent out of the nucleus to ribosomes for translation. What occurs next as the mRNA strand moves along the ribosome?
The tRNA transfers amino acids to line up with mRNA to create the code for the proteins
This is an organism or cell with two sets of chromosomes.
Diploid
Design a Punnett square that results in 75% dominant and 25% recessive phenotypes and justify your choice.
A heterozygous × heterozygous cross (Aa × Aa) produces a 3:1 ratio.
Use evidence from Mendelian inheritance to explain why siblings can have different traits even with the same parents.
Alleles separate randomly during gamete formation, leading to different allele combinations in offspring.
Name the three parts of a DNA nucleotide.
Phosphate group, deoxyribose sugar, nitrogen base
When comparing two family members with different appearances, it is assumed that their phenotypes are connected to differences in their DNA. What components of the DNA are responsible for the phenotype differences between the related individuals?
The sequence or order of bases can be different and the expression of genes can be different for individuals.