Lab 1: Genetics, Patterns of Inheritance, and Scientific Inquiry.
Biology II Laboratory BSC1011L Authors: AG BJ NB AN SF JR BJ BE Version 3Sep2022
Material is also covered in Chapters 14, and 22-23 of Campbell Biology, 12th Ed., Urry, Cain, Wasserman, Minorsky and
Reece.
Group members: ______________________________________ ____________________________________
__________________________________________ ______________________________________________
KEY CONCEPTS:
1. Alleles are alternate forms of a gene and are found on chromosomes. In diploid individuals, alleles occur in pairs
and their genetic makeup is called the genotype. The phenotype is the physical expression of the genotype.
2. Genes are inherited in predictable ways, and the Punnett square can be used to predict the genotype frequencies
and phenotype frequencies of future generations.
3. Pedigrees can be used to follow patterns of inheritance in families.
4. Gregor Mendel discovered two laws of science by breeding peas and noting the changes in phenotype
frequencies between generations. These laws can be used to predict the possible genotypes as well as predict the
genotype and phenotype frequencies (%) of future generations.
5. Scientific inquiry is based on hypotheses, laws, and theories. In science, theories are explanations of patterns
that have been so thoroughly tested that scientists agree they are true and correct.
SKILLS YOU SHOULD MASTER BY THE END OF THE LAB:
1. Be able to use the vocabulary of genetics to answer questions about genetics and solve simple problems.
2. Be able to answer questions about patterns of inheritance of alleles in single genes.
3. Be able to work simple genetics problems using Punnett squares.
4. Be able to follow genes through a pedigree.
5. Know the difference between hypotheses, laws and scientific theories.
VOCABULARY:
Chromosomes Genotype True breeding
Homologous Chromosomes Phenotype P, F1, F2 generations
Gene Heterozygote Punnett square
Allele Homozygote Hypothesis
Diploid Dominant Law, Mendel’s Laws
Haploid Recessive Theory (scientific)
STUDY TIP: TO STUDY FOR THE QUIZZES AND EXAMS, PAY ATTENTION TO:
Lab1: Genetics and Inheritance
• Key Concepts for each lab
• Skills you should master by the end of the lab.
• Vocabulary (words in bold).
1
, Part 1: Learn genetic concepts and vocabulary.
A. Genes are found at specific locations on chromosomes and chromosomes come in homologous pairs.
The different forms of genes on homologous chromosomes are called alleles.
Chromosome-The very long molecule of DNA and proteins that carry genetic information within cells. Humans have 46
chromosomes in most cells.
Gene–The portion of a chromosome that carries the genetic information for a character. For example, the gene for flower
color, or the gene for pea shape.
Locus–The physical place of a gene on the chromosome. Loci is pleural for locus; different genes have different loci.
Allele–The alternate forms of a gene. For example, the gene for flower color can have an allele for a purple color or a white
color.
Alleles can be noted in several ways. For example, purple color might be noted as “A”, and white might be noted as “a”.
The notations A, a, B, d, A1, A2, A3, A45 are all appropriate notations. The alleles for sickle cell anemia are called HbS,
and HbA but in this lab we will use single letters (S, A) because it is easier to work problems with simple notation.
Homologous chromosomes–Chromosome that have the same genes in the same location in a cell (see Figure 1).
Genes on homologous chromosomes are at the same locus, but they may have different allelic composition (genotype).
For example, the gene for flower color in Figure 1 has one allele for purple color and one allele for white color.
Figure 1. One pair of homologous chromosomes Figure 2. The 22 pairs of homologous
showing two different alleles at the locus for the chromosomes in a human male, as shown in
flower color. a karyotype. The one pair of sex chromosomes in
males is not homologous because the
chromosomes have different genes.
The fern, Ophioglossum reticulatum has 630 pairs of homologous chromosomes. What is the total number of
chromosomes it has in each cell? __________
The dolphin, has 44 total chromosomes, how many pairs of homologous chromosomes does it have? __________
B. Cells can be haploid or diploid; they can have one or two sets of chromosomes.
Diploid–Having two sets of chromosomes, one from each parent. Most cells in humans are diploid and have two sets
of 23 chromosomes, or 46 in all. Note, “di” means two, and “ploid” refers to the number of sets so diploid means
“two sets”.
Haploid–Having a single set of chromosomes. Gametes (egg and sperm) have a single set of chromosomes. Human
Lab1: Genetics and Inheritance
gametes have one set of 23 chromosomes. Some organisms, such as many fungi, live most of their life as haploid
organisms and have only short transient diploid stages.
Critical thinking: What does the term triploid mean? ______________________________________________
Banannas are triploid and have 11 chromosomes in one set. How many chromosomes are in each cell? __________
Remember: How many alleles can a haploid gamete have for one gene? ________
2
Biology II Laboratory BSC1011L Authors: AG BJ NB AN SF JR BJ BE Version 3Sep2022
Material is also covered in Chapters 14, and 22-23 of Campbell Biology, 12th Ed., Urry, Cain, Wasserman, Minorsky and
Reece.
Group members: ______________________________________ ____________________________________
__________________________________________ ______________________________________________
KEY CONCEPTS:
1. Alleles are alternate forms of a gene and are found on chromosomes. In diploid individuals, alleles occur in pairs
and their genetic makeup is called the genotype. The phenotype is the physical expression of the genotype.
2. Genes are inherited in predictable ways, and the Punnett square can be used to predict the genotype frequencies
and phenotype frequencies of future generations.
3. Pedigrees can be used to follow patterns of inheritance in families.
4. Gregor Mendel discovered two laws of science by breeding peas and noting the changes in phenotype
frequencies between generations. These laws can be used to predict the possible genotypes as well as predict the
genotype and phenotype frequencies (%) of future generations.
5. Scientific inquiry is based on hypotheses, laws, and theories. In science, theories are explanations of patterns
that have been so thoroughly tested that scientists agree they are true and correct.
SKILLS YOU SHOULD MASTER BY THE END OF THE LAB:
1. Be able to use the vocabulary of genetics to answer questions about genetics and solve simple problems.
2. Be able to answer questions about patterns of inheritance of alleles in single genes.
3. Be able to work simple genetics problems using Punnett squares.
4. Be able to follow genes through a pedigree.
5. Know the difference between hypotheses, laws and scientific theories.
VOCABULARY:
Chromosomes Genotype True breeding
Homologous Chromosomes Phenotype P, F1, F2 generations
Gene Heterozygote Punnett square
Allele Homozygote Hypothesis
Diploid Dominant Law, Mendel’s Laws
Haploid Recessive Theory (scientific)
STUDY TIP: TO STUDY FOR THE QUIZZES AND EXAMS, PAY ATTENTION TO:
Lab1: Genetics and Inheritance
• Key Concepts for each lab
• Skills you should master by the end of the lab.
• Vocabulary (words in bold).
1
, Part 1: Learn genetic concepts and vocabulary.
A. Genes are found at specific locations on chromosomes and chromosomes come in homologous pairs.
The different forms of genes on homologous chromosomes are called alleles.
Chromosome-The very long molecule of DNA and proteins that carry genetic information within cells. Humans have 46
chromosomes in most cells.
Gene–The portion of a chromosome that carries the genetic information for a character. For example, the gene for flower
color, or the gene for pea shape.
Locus–The physical place of a gene on the chromosome. Loci is pleural for locus; different genes have different loci.
Allele–The alternate forms of a gene. For example, the gene for flower color can have an allele for a purple color or a white
color.
Alleles can be noted in several ways. For example, purple color might be noted as “A”, and white might be noted as “a”.
The notations A, a, B, d, A1, A2, A3, A45 are all appropriate notations. The alleles for sickle cell anemia are called HbS,
and HbA but in this lab we will use single letters (S, A) because it is easier to work problems with simple notation.
Homologous chromosomes–Chromosome that have the same genes in the same location in a cell (see Figure 1).
Genes on homologous chromosomes are at the same locus, but they may have different allelic composition (genotype).
For example, the gene for flower color in Figure 1 has one allele for purple color and one allele for white color.
Figure 1. One pair of homologous chromosomes Figure 2. The 22 pairs of homologous
showing two different alleles at the locus for the chromosomes in a human male, as shown in
flower color. a karyotype. The one pair of sex chromosomes in
males is not homologous because the
chromosomes have different genes.
The fern, Ophioglossum reticulatum has 630 pairs of homologous chromosomes. What is the total number of
chromosomes it has in each cell? __________
The dolphin, has 44 total chromosomes, how many pairs of homologous chromosomes does it have? __________
B. Cells can be haploid or diploid; they can have one or two sets of chromosomes.
Diploid–Having two sets of chromosomes, one from each parent. Most cells in humans are diploid and have two sets
of 23 chromosomes, or 46 in all. Note, “di” means two, and “ploid” refers to the number of sets so diploid means
“two sets”.
Haploid–Having a single set of chromosomes. Gametes (egg and sperm) have a single set of chromosomes. Human
Lab1: Genetics and Inheritance
gametes have one set of 23 chromosomes. Some organisms, such as many fungi, live most of their life as haploid
organisms and have only short transient diploid stages.
Critical thinking: What does the term triploid mean? ______________________________________________
Banannas are triploid and have 11 chromosomes in one set. How many chromosomes are in each cell? __________
Remember: How many alleles can a haploid gamete have for one gene? ________
2
