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Name _________KEY___________________________
Period
PAP Biology
Genetics (Chapter 8) & Biotechnology (Chapter 11) Test Review
The test covers the notes we took in class, activities and problems done in class, and the
book.
1. Define
a. Homozygous – having the same alleles for a trait (AA or aa)
b. Heterozygous – having different alleles for a trait (Aa)
c. Dominant – the expressed form of a trait
d. Recessive – the trait that is not expressed when the dominant form is present
e. Autosomal – not linked to a sex chromosome
f.
Sex-linked – linked to a sex chromosome
g. Genotype – the combination of genes for a specific trait
h. Phenotype – an organism’s appearance that results from the genotype and
environment
2. How do you represent dominant and recessive alleles using letters? Capital letter (first
letter of dominant trait) represents a dominant trait; lower case of same letter represents
recessive trait
3. What is genetics? The science of heredity and mechanisms of inheritance
4. What is heredity? The passing of genetic traits from parent to offspring
5. Who was the father of genetics? Gregor Mendel
6. Be able to analyze a pedigree. (know how relationships are represented in the diagram,
determine if the pattern is dominant or recessive, determine possible genotypes for
individuals in pedigree)
7. Does a parent have to show a trait in order for their offspring to show it? No, parent could
be a “carrier” of a recessive allele.
8. What is codominance? A condition in which both alleles for a gene are fully expressed
9. What is incomplete dominance? A condition in which a trait in an individual is
intermediate between the phenotype of the individual’s two parents.
10. What is a polygenic trait? A characteristic of an organism that is determined by many
genes.
11. If a trait appears in every generation, it is usually ____dominant______________________.
12. If a trait skips generations, it is usually _____recessive____________________.
13. If a trait is more common in males than females, it is usually ____sex-linked_______________.
14. What does the law of independent assortment state? The genes separate independently
of one another in meiosis
Name _________KEY___________________________
Period
PAP Biology
15. What does the law of segregation state? Pairs of homologous chromosomes separate in
meiosis so that only one chromosome (one allele for each gene) from each pair is
present in each gamete.
16. Be able to do Punnett squares and answer questions about the results. (show an
example similar to homework practice)
17. Be able to do crosses and figure out the expected genotype and phenotype ratios. (Be
familiar with ratio, percentage, fraction, and decimal conversions.)
18. Be able to determine genetic probability for a single trait. (What is the chance of
something happening?)
19. How can you determine the genotype of an individual that shows the dominant
phenotype? Do a test cross (cross with homozygous recessive) and examine the
phenotype of the offspring. This will distinguish a homozygous dominant genotype from a
heterozygous genotype in the parent.
20. What kind of trait is colorblindness? X-linked
21. What kind of trait is hemophilia? X-linked
22. What is the example of multiple alleles that we talked about in class? ABO blood type
23. Be able to do crosses for blood type.
24. What is a mutation? Any change in the sequence of DNA
25. What is genetic counseling? A process that uses karyotypes and pedigrees to help
identify parents at risk for passing on genetic disorders to their children and assists parents
in making decisions about having children.
26. What is a karyotype and what can it tell you about an individual? A picture of an
individual’s chromosomes arranged in order. It can tell you the number and structure of
chromosomes in an individual
27. Describe the karyotype of an individual with Down syndrome. Has three copies of
chromosome 21 (trisomy 21).
28. What would the sex chromosomes be in a female? XX
A male? XY
29. In your own words describe the process of electrophoresis. Pg 231 DNA fragments are
placed in one end of a slab of gel and near the negative electrode. Since DNA is
negatively charged, it migrates (moves) from the negative end toward the positive
electrode when an electric field is applied.
30. Which DNA fragments move fastest? Smaller fragments
Which move slowest? Larger
fragments
31. Where would you expect to find the largest fragments in a gel? Nearest the negative
electrode (near the well)
The smallest fragments? Closest to the positive electrode
Name _________KEY___________________________
Period
PAP Biology
32. What is electrophoresis used for? Separating fragments of DNA according to size (in base
pairs)
33. What is a DNA fingerprint? The pattern of bands that results when an individual’s DNA
fragments are separated
34. What is Polymerase Chain Reaction (PCR)? A process used to make many copies of
selected segments of DNA. This is often needed when only a small sample is available for
analysis (i.e., evidence obtained at a crime scene).
35. What is the goal of the Human Genome Project? Map (find the location of) the genes on
human chromosomes
36. What is genetic engineering? Manipulating genes for practical purposes
37. Describe how bacteria are used to produce human genes. (ex insulin) 1) DNA is cut in
human DNA and bacterial plasmid DNA. 2) Human gene is inserted into bacteria and
the two combine. 3) The gene is cloned as bacteria reproduce. 4) Bacteria with the
desired human gene are isolated to produce the protein of interest (insulin, for example).
38. Define the following terms:
a. Recombinant DNA – DNA made from two or more different organisms
b. Restriction enzymes – bacterial enzymes that recognize specific sequences and
cut between specific nucleotides within the sequence
c. Plasmids – circular DNA molecules in bacteria separate from the main bacterial
chromosome
d. DNA ligase – enzyme that helps bond DNA fragments together
e. Sticky ends – the cut ends of the DNA to be joined
39. How do scientists genetically modify food? They add favorable traits to the plants by
manipulating the plant’s genes, including inserting genes from bacteria.
40. What is cloning? Cloning is using a differentiated cell (a cell that has become
specialized, such as liver cell or mammary cell) from an adult organism to produce
another genetically identical organism. (DNA from egg or sperm is not used.) The DNA
from an egg cell is removed and placed next to the differentiated cell. An electric
stimulus is used to fuse the cells and trigger division. The embryo then develops in a
surrogate mother. The new organism is genetically identical to the organism from which
the differentiated cell is extracted.