In humans, a gene that has been identified as causing a type of skin cancer is the
A. sonic hedgehog.
B. superwoman echidna.
C. mutant mole rat.
D. mutant superman.
E. superhero aardvark.
An allele is
A. the main factor determining a trait.
B. always one of a pair.
C. always recessive.
D. an alternate form of a gene.
E. the dominant form of a gene.
Sickle cell anemia is an example of what type of inheritance?
A. complete dominance
B. recessive dominance
D. multiple alleles
E. incomplete dominance
If you view a cell in which the genetic material is beginning to be visible as separate bodies, and the nucleus has disappeared from view, you may surmise that the cells is in
In what phases is the genetic material in the cell correctly referred to as chromatids?
A. interphase and telophase
B. interphase and prophase
C. anaphase and metaphase
D. metaphase and telophase
E. metaphase and prophase
Tall corn plants (T) are dominant to dwarf plants (tt). Solid green leaves (G) are dominant to leaves with a white tip (gg). A cross between two corn plants yielded the following phenotypes: 51 tall plants with a white tip on their leaves; 43 dwarf plants with solid leaves; 48 dwarf plants with white tips on their leaves; 45 tall plants with solid leaves. What are the genotypes of the parents that produced these plants?
A. TtGg x ttgg
B. TtGg x Ttgg
C. None of the above
D. ttGG x TTgg
E. TtGg x TtGg
Gregor Mendel was successful in his analysis of the genetics of pea plants because
A. he studied the parental plants to determine their differences.
B. pea plants have genetics different from other organisms.
C. he examined and analyzed both the F1 and F2 generations.
D. he studied a trait that had a strange inheritance pattern.
E. he decided to only look at his results in an objective manner.
What structure holds the sister chromatids to the spindle fibers?
Cytokinesis in plant cells differs from cytokinesis in animal cells because
A. plant cells have a rigid cell wall.
B. the contractile protein, actin, is important only in plant cells.
C. in plant cells, the cell plate must also divide into two parts.
D. a contractile ring forms only in plant cells.
E. there is no difference.
If an organism’s diploid chromosome number is 18 how many different possible combinations of homologous chromosomes lining up during meiosis exist for the eggs or sperm produced by that organism?
Skin cancers typically develop in the
A. lower layers of the dermis.
B. upper layers of the epidermis.
C. subcutaneous layer.
D. upper layers of the dermis.
E. lower layers of the epidermis.
Mendel observed that dominant traits
A. are only expressed in hybrids.
B. are seen in all of the F1 hybrid pea plants in his experiments.
C. were the only traits seen in the F2 generation of pea plants in his experiments.
D. are expressed in all plants.
E. were absent in the F1 generation of pea plants that he used in his experiments.
QUESTION 13 Consider two traits for an organism, determined by two genes, each of which is governed by at least two alleles. In the case of a dihybrid individual, the gametes formed will be of either the parental type or the recombinant type. Recombinant type gametes are formed because of
A. incomplete dominance.
B. the principle of dihybrids.
D. independent assortment.
E. multiple alleles.
At the end of metaphase I, _______________ separate.
A. sister chromatids
B. homologous chromosomes
C. haploid chromatids
E. germ cells
Special cells found in the gonads that give rise to gametes upon division are called
A. basal cells.
B. germ cells.
C. somatic cells.
D. egg cells.
E. stem cells.
After the DNA is replicated, and it condenses in prophase, two identical rods of DNA are seen. These are
A. spindle fibers.
QUESTION 17 The segregation principle states that in sexually reproducing diploid organisms the two copies of each gene
A. will both wind up in either the sperm or egg.
B. must always be the same allele.
C. move together as a unit during meiosis.
D. separate from each other during meiosis