Bio Exam 2 HW Q's

In a population of organisms with 4 alleles, how many homozygous genotypes are possible? How many heterozygous genotypes are possible? 3; 3 4; 4 3; 4 4; 10 4; 6

4; 6

The second meiotic division resembles mitosis because: A. all of these choices are correct chromosomes decondense during telophase II B. spindle microtubules attach from opposite directions to the centromere of each sister chromatid pair C. sister chromatids are separated during anaphase II to become the chromosomes of the daughter cells D. the daughter cells have the same number of chromosomes as the parent cell

A. all of these choices are correct

Phenotypic variation among individuals is not always visible and can include which of the following trait characteristics? A. developmental, physiological, and behavioral differences B. only physiological differences C. developmental and physiological differences D. only behavioral differences E. only developmental differences

A. developmental, physiological, and behavioral differences

A male child is born with an XYY constitution of sex chromosomes. The parents are normal XX and XY individuals, so their child's genotype must be the result of nondisjunction in the formation of one of their gametes. When (and in whom) could the nondisjunction have taken place? A. in the father in meiosis II B. in the father in meiosis I C. in the mother in meiosis I D. in the father in mitosis E. in the zygote at the first mitotic division

A. in the father in meiosis II

Large chromosomal inversions can cause problems in which of the following processes? A. meiosis B. DNA replication C. mitosis D. reciprocal translocation E. none of the other answers are correct

A. meiosis

Consider an A-T versus G-C single-nucleotide polymorphism (SNP) in the human genome. This means that the DNA molecules in the population at this site have which combinations of base pairs? A. A-T or G-T or G-C B. A-T or G-C C. A-C or G-T D. A-T or A-C or G-T or G-C E. A-T or A-G or G-C

B. A-T or G-C

Consider the tryptophan codon 5′-UGG-3′ in the standard genetic code. Can a single base change in this codon create a synonymous mutation? Can a single base change in this codon create a nonsense codon? A. yes, yes B. no; yes C. no; no D. yes; no

B. No ; yes

If you crossed two heterozygous yellow-seed pea plants (genotypes Aa), the relative frequency of: A. green-seed plants (genotype aa) in the offspring would be ¼ B. all of these choices are correct C. homozygous yellow-seed plants (genotype AA) in the offspring would be ¼ D. the A allele in each parent's gametes would be ½ the a allele in each parent's gametes would be ½

B. all of these choices are correct

Deletions that eliminate a multiple of three nucleotides can: A. shorten chromosomes from the telomeres inward B. delete amino acids in a polypeptide chain C. cause frameshift mutations in a reading frame D. cause nonsense mutations in a reading frame E. only occur in somatic cells

B. delete amino acids in a polypeptide chain

A cell in prophase I of meiosis has ______________ as much DNA as each of the daughter cells following cytokinesis of meiosis II. A. half B. four times C. twice D. one quarter

B. four times

A cell in prophase I of meiosis has ______________ as many chromosomes as each of the daughter cells following cytokinesis of meiosis II. A. half B. twice C. four times D. one quarter

B. twice

Consider a diploid organism with a haploid complement of four chromosomes. At prophase I, how many total chromosomes will be present in a cell? A. 16, four pairs of homologous chromosomes and two sister chromatids per chromosome B. 4, one complete set of chromosomes C. 8, four pairs of homologous chromosomes D. 12, four pairs of homologous chromosomes and their haploid complement

C. 8, four pairs of homologous chromosomes

In pea plants, flowers are either white or purple; the purple color is produced by pigments called anthocyanins. The production of anthocyanins is a two-step process: the first is controlled by the C gene and the second by the P gene. Both genes must produce functional proteins for anthocyanin to be produced. For each gene, the dominant (C and P) alleles produce functional proteins. Which of the following genotypes will produce white (no pigment) flowers? A. CCpp only B. ccPP and CcPP C. ccPP and CCpp D. CcPP only E. ccPP only

C. ccPP and CCpp

The FoxP2 gene is thought to be involved in language in humans. At prophase I, how many copies of the FoxP2 gene are present in a cell? A. eight copies, one on each strand of each chromatid per homologous pair B. two copies, one on each homologous chromosome C. four copies, one on each sister chromatid in a pair of homologous chromosomes D. eight copies, one on each sister chromatid in a pair of homologous chromosomes

C. four copies, one on each sister chromatid in a pair of homologous chromosomes

According to the principle of segregation, a heterozygous plant with alleles Aa will produce: A. some gametes with the A allele and some with the a allele, but in no predictable ratio B. gametes in the ratio of 3 A alleles:1 a allele C. gametes in the ratio of 1 A allele:1 a allele D. gametes with only the A allele E. gametes with only the a allele

C. gametes in the ratio of 1 A allele:1 a allele

The statement that, in garden peas, yellow seed is dominant to green seed means that: A. when a true-breeding yellow seed parent is crossed with a true-breeding green seed parent, all offspring will have green seeds B. when a true-breeding yellow seed parent is crossed with a true-breeding green seed parent, ¾ of the offspring will have yellow seeds and ¼ will have green seeds C. when a true-breeding yellow seed parent is crossed with a true-breeding green seed parent, all offspring will have yellow seeds D. we can't predict seed color in the offspring of a true-breeding yellow seed parent and a true-breeding green seed parent E. when a true-breeding yellow seed parent is crossed with a true-breeding green seed parent, ½ of the offspring will have yellow seeds and ½ will have green seeds

C. when a true-breeding yellow seed parent is crossed with a true-breeding green seed parent, all offspring will have yellow seeds

During meiosis, genetic variability is introduced during which of the following phases? SELECT ALL THAT APPLY. A. prophase II B. anaphase II C. Metaphase II D. Prophase I E. Metaphase I D. Telophase I

D. Prophase I E. Metaphase I

With independent assortment, the ratio of phenotypes in the F2 generation of a cross between true-breeding strains (AA bb x aa BB) can be described as 9:3:3:1 when A and B are dominant over a and b. To what phenotype do the "3"s in the ratio refer? A. dominant for both traits B. recessive for both traits C. dominant for the A trait and recessive for the B trait D. dominant for one trait and recessive for the other

D. dominant for one trait and recessive for the other

Sister chromatids are separated during: A. meiosis I and mitosis B. meiosis I only C. meiosis II only D. meiosis II and mitosis E. mitosis only

D. meiosis II and mitosis

In meiosis, recombination occurs: A. during prophase I and II and involves exchange of chromosome fragments between all four chromatids B. during prophase I and II and involves exchange of chromosome fragments between sister chromatids C. only during prophase I and involves exchange of chromosome fragments between sister chromatids D. only during prophase I and involves exchange between chromatids of homologous (non-sister) chromosomes

D. only during prophase I and involves exchange between chromatids of homologous (non-sister) chromosomes

Which of the following happens during prophase I of meiosis? A. recombination between sister chromatids of homologous chromosomes B. recombination between sister chromatids of nonhomologous chromosomes C. recombination between non-sister chromatids of nonhomologous chromosomes D. recombination between non-sister chromatids of homologous chromosomes

D. recombination between non-sister chromatids of homologous chromosomes

Which of the following statements applies to frameshift mutations? A. they create a premature stop codon at the site of mutation B. they are most common in non-coding regions of the genome C. they cause the insertion or deletion of a single amino acid from the polypeptide chain D. they change the amino acid sequence downstream from the mutant site

D. they change the amino acid sequence downstream from the mutant site

In a diploid individual, one chromosome carries A and B genes, and the homologous chromosome carries different forms (alleles) of these same genes, a and b. If there is a single crossover between these two genes involving non-sister chromatids during prophase I of meiosis, the resulting four gametes are: HINT: Draw the tetrad with the four alleles (A, B, a, b) during prophase I, then modify it to show the single crossover event. A. Ab, Ab, aB, aB B. AB, AB, ab, ab C. AaBb, AaBb, AaBb, AaBb D. AB, ab, AB, ab E. AB, Ab, aB, ab

E. AB, Ab, aB, ab

If blending inheritance was an accurate model of transmission genetics, which of the following would be true? A. Variation in natural populations would increase over time B. Variation would increase in some populations, decrease in some populations, and remain the same in some populations C. Mutation would not contribute to variation in natural populations D. Variation in natural populations would remain the same over time E. Variation in natural populations would decrease over time

E. Variation in natural populations would decrease over time

Which of the following is most likely to result in a nonfunctional polypeptide? A. a missense mutation B. a transition mutation C. silent and missense mutations are the most likely to result in a nonfunctional polypeptide D. a silent mutation E. a nonsense mutation

E. a nonsense mutation

You are given two true-breeding groups of rabbits. The first group has floppy ears and white coat color. The second group has straight ears and black coat color. When you perform a cross of these two groups to obtain an F1 generation, you see that all of your rabbits have floppy ears and grey coat color. Which of the following possibilities appears to be supported by what you see in the F1 generation? A. straight ears are dominant over floppy ears; white coat color is dominant over black coat color straight ears are dominant over floppy ears; white coat color is dominant over black coat color B. floppy ears are dominant over straight ears; black coat color is dominant over white coat color floppy ears are dominant over straight ears; black coat color is dominant over white coat color C. floppy ears are dominant over straight ears; white coat color is dominant over black coat color floppy ears are dominant over straight ears; white coat color is dominant over black coat color D. straight ears are dominant over floppy ears; black coat color is dominant over white coat color straight ears are dominant over floppy ears; black coat color is dominant over white coat color E. floppy ears are dominant over straight ears; coat color is determined by incomplete dominance floppy ears are dominant over straight ears; coat color is determined by incomplete dominance F. straight ears are dominant over floppy ears; coat color is determined by incomplete dominance

E. floppy ears are dominant over straight ears; coat color is determined by incomplete dominance floppy ears are dominant over straight ears; coat color is determined by incomplete dominance

_____ mutations affect only the individual in which they occur; _____ mutations are passed from parent to offspring. A. germ-line; point B. germ-line; somatic C. point; germ-line D. somatic; point E. somatic; germ-line

E. somatic; germ-line