bio test final 3
Terms
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- Asexual reproduction
- requires only one parent.
- Each unique form of the same gene is called:
- an allele.
- Crossing over occurs during:
- prophase I
- At the end of telophase II there are:
- four haploid daughter cells.
- During crossing over, ________ undergo breakage and exchange segments.
- nonsister chromatids of a homologous pair
- What is the formula for determining how many combinations of chromosomes there can be in gametes, where n is the number of chromosomes?
- 2n
- In plants, a zygote develops into a:
- sporophyte
- How many haploid ova, or egg cells, are formed from one diploid oogonium?
- 1
- How many haploid spermatid, are formed from one diploid spermatogonium?
- 4
- The location of a specific gene on a particular type of chromosome is a:
- gene locus.
- If two plants that are both heterozygous for a trait (i.e., Aa) are crossed, what percentage of their offspring will also be heterozygous for that trait?
- 50%
- Gregor Mendel was the first to describe:
- the law of independent assortment.
- The Punnett-square method is used to predict:
- probable outcomes of genetic crosses.
- When a heterozygote's phenotype shows a mixture of the phenotypes of two homozygotes because one allele of the pair is not fully dominant over its partner, this is called:
- incomplete dominance.
- If an ABO blood typing reveals that you are homozygous recessive (ii), your blood type:
- must be O.
- Pink snapdragons are heterozygous for a red and a white allele; their color is an example of incomplete dominance. If two pink snapdragons are crossed, what colors can you expect in their offspring?
- 100% pink
- In a bar graph showing the range of variation for a trait, the shortest bar represents:
- the category with the least number of individuals.
- All molecular forms of the same gene are called:
- alleles
- When two alleles on homologous chromosomes are identical, this is called:
- homozygous
- An individual's observable traits are called the:
- phenotype
- Offspring of a cross between true-breeding lineages that inherit nonidentical alleles are called:
- hybrids
- Crossing over during meiosis results in combinations of alleles not present in the parental cell.
- True
- A human sperm carrying a Y chromosome fertilizes an egg. Assuming the egg is normal, what sex will the offspring be?
- male
- The probability that a crossover will disrupt the linkage between two genes is proportional to:
- the distance between the genes.
- The human X chromosome:
- is much larger than the Y chromosome.
- Genes that are closely linked:
- are rarely separated by crossing over.
- What standardized symbols are used to represent males and females on a pedigree?
- a square for males and a circle for females
- Huntington disease is governed by autosomal dominant inheritance. What is the likelihood that a person who has one heterozygous affected parent and one normal parent will develop the disease?
- 50%
- Galactosemia is governed by autosomal recessive inheritance. What is the likelihood that a person who has one affected parent and one homozygous normal parent has the disorder?
- 0% (impossible)
- If a man has hemophilia (an X-linked recessive trait) and his wife is homozygous for the normal allele,
- all daughters will be carriers.
- Cri-du-chat syndrome is a genetic disorder caused by:
- a deletion from chromosome 5.
- Down syndrome:
- is also known as trisomy 21.
- A gene's most common form is called the:
- wild-type allele.
- A human sperm carrying a Y chromosome fertilizes an egg. Assuming the egg is normal, what sex will the offspring be?
- male
- The probability that a crossover will disrupt the linkage between two genes is proportional to:
- the distance between the genes.
- The human X chromosome:
- is much larger than the Y chromosome.
- Genes that are closely linked:
- are rarely separated by crossing over.
- What standardized symbols are used to represent males and females on a pedigree?
- a square for males and a circle for females
- If a man has hemophilia (an X-linked recessive trait) and his wife is homozygous for the normal allele,
- all daughters will be carriers.
- Cri-du-chat syndrome is a genetic disorder caused by:
- a deletion from chromosome 5.
- A gene's most common form is called the:
- wild-type allele.
- What happened when Griffith injected mice with heat-killed S bacteria?
- The mice lived and had no live bacteria in their blood.
- Griffith showed that mice injected with heat-killed S cells and live R cells will die. Knowing the results of his three other control experiments, Griffith could conclude:
- the hereditary material of S cells was not destroyed by heat and had transformed the normally harmless R strain into a killer.
- Bacteriophages consist only of:
- proteins and nucleic acids.
- What element is found in protein but not DNA?
- sulfur
- The complementary bases of the two strands of DNA are held together by:
- hydrogen bonds.
- What component of DNA forms the backbone of each strand?
- sugars and phosphates
- Which of the following is not a component of a nucleotide?
- glycerol
- A pyrimidine always base-pairs with:
- a purine.
- The phrase "semiconservative replication" refers to the fact that:
- half of the parent DNA double helix is conserved during replication.
- During DNA replication,
- DNA polymerase attaches short stretches of free nucleotides to the parent template.
- The genetic material used to create Dolly was derived from a(n):
- cell from an adult sheep's udder.
- Dolly was genetically identical to:
- the sheep that donated the nucleus that formed her first cell.
- The first step in building a protein from the instructions in the genes is ________ of the DNA.
- transcription
- The five-carbon sugar in RNA is:
- ribose
- The enzyme that catalyzes the formation of RNA during transcription is:
- RNA polymerase.
- After transcription, eukaryotic mRNA:
- is modified by enzymes that remove the introns, add a tail, and add a cap.
- Which of the following is not an anticodon?
- TAG
- A base triplet in mRNA is a(n):
- codon
- Which change in a codon would be least likely to change the amino acid specified?
- third nucleotide in the codon
- DNA segments that move spontaneously from one region of the genome to another are:
- transposons
- Each ribosome has _________ subunits.
- two
- Peptide bonds link
- amino acids in a polypeptide.
- Base-pair substitution results in a mutation when:
- a base is mismatched during replication, and a protein incorporates the wrong amino acid.
- Which of the following would cause a frameshift mutation?
- an insertion