Genetics - AP Biology

Haploid cells contain only one of each numbered chromosome, whereas diploid cells contain two of each. Therefore, a haploid cell in a given organism would contain half as many chromosomes as would be in a diploid cell of the same organism.

A gamete will have n=23 chromosomes while a somatic cell is going to have a diploid number of cells, or 2n=46. This is the case because somatic cells are going to receive a copy of chromosomes from each parent, so 23 from the mother and 23 form the father to give 46 total chromosomes. If you are ever given the haploid number and asked for the diploid number, then you can simply double the haploid number.

In DNA, the four nucleic acid basis are adenine, guanine, cytosine, and thymine. RNA has uracil instead of thymine. Adenine pairs with thymine in DNA and uracil in RNA. Cytosine and Guanine pair together in both. Deoxyribose and ribose are the 5-carbon sugars in DNA and RNA nucleotides, respectively.

Haploid cells contain one of each numbered chromosome, for a chromosome number of "n." Diploid cells contain two of each, so the number of chromosomes in a diploid cell is 2n, or twice the haploid number.

This question is essentially asking, "Which of the following is a point mutation of the original sequence?" A point mutation is a mutation in which one base pair of DNA is substituted for another. A point mutation will not change the reading frame of a DNA sequence because it does not involve adding or removing any bases. The only answer choice that is identical to the original sequence with the exception of one base pair being changed for another is 5'GATCACG3', so this is the correct answer.

A phenotype is a physical trait that can be observed. Thus, eye color (and hair color) are great examples of phenotypes. A genotype describes the genetic traits of a person (e.g. whether that person has the autosomal or recessive alleles of a gene). The genotype of an individual determines his or her phenotype.

All three contribute to giving rise to genetic variation. Independent assortment allows for the chromosomes to assort in millions of random of combinations during fertilization. Crossing over between chromosomes produces recombinant chromosomes, or the combination of chromosomal DNA from two parents into one chromosome. Random fertilization allows aids with variation because it means any sperm can fertilize any egg. It is sometimes easy to overlook, but humans do not mate randomly. Lots of energy is put into choosing an optimal mate with whom to reproduce.

The correct answer is "X-linked." Mammalian females have two X chromosomes, with recessive alleles often not apparent unless there are two copies. Mammalian males have only one X chromosome, so any recessive alleles on it will be expressed.

A red flower must have the "R" allele, which conveys the red phenotype. Since this red allele is dominant, the flower will be red as long as one copy of this allele is present. Thus, the genotypes "Rr" and "RR" will both produce red flowers. If no red allele is present ("rr"), the flower will be white.

The correct answer is the "S," or synthesis, phase. The cell cycle consists of six main parts: interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. Interphase, the longest part of the cell cycle, is subdivided into three different phases: G1, S, and G2. G1 comes first; in this phase, the cell simply grows. In the S phase, the cell synthesizes (creates) a new set of DNA using its original genome as a template. In G2, the cell (which now contains two copies of DNA) continues to grow. These growth phases are an important part of interphase because the cell must grow enough to have enough cytoplasm to give to each of its daughter cells at the end of mitosis or meiosis.

A phenotype is a physical trait that can be observed. Thus, eye color (and hair color) are great examples of phenotypes. A genotype describes the genetic traits of a person (e.g. whether that person has the autosomal or recessive alleles of a gene). The genotype of an individual determines his or her phenotype.

All three contribute to giving rise to genetic variation. Independent assortment allows for the chromosomes to assort in millions of random of combinations during fertilization. Crossing over between chromosomes produces recombinant chromosomes, or the combination of chromosomal DNA from two parents into one chromosome. Random fertilization allows aids with variation because it means any sperm can fertilize any egg. It is sometimes easy to overlook, but humans do not mate randomly. Lots of energy is put into choosing an optimal mate with whom to reproduce.

The correct answer is "X-linked." Mammalian females have two X chromosomes, with recessive alleles often not apparent unless there are two copies. Mammalian males have only one X chromosome, so any recessive alleles on it will be expressed.

If other dingos are supplementing the population, we know that migration is occurring. Migration cannot occur if a population is to satisfy the conditions of Hardy-Weinberg equilibrium.

The phenotypic ratio is the ratio of one phenotype to another (phenotype is the trait expressed, in this case color, while genotype is the allele combination (BB, bb, Bb, or bB) that produces that phenotype. The capital letters BB signify that the blue allele (B) is dominant to the white allele (b). As such, the only genotype that will produce white plants is bb. All other combinations (BB, Bb, bB) will produce a blue plant. If you cross a homozygous (both dominant or both recessive) dominant plant with a homozygous recessive plant, the dominant allele will be present in all of the offspring, as every possible allele the blue plant could contribute will be dominant to every possible allele the white plant could contribute, making all of the offspring blue.

A red flower must have the "R" allele, which conveys the red phenotype. Since this red allele is dominant, the flower will be red as long as one copy of this allele is present. Thus, the genotypes "Rr" and "RR" will both produce red flowers. If no red allele is present ("rr"), the flower will be white.

If other dingos are supplementing the population, we know that migration is occurring. Migration cannot occur if a population is to satisfy the conditions of Hardy-Weinberg equilibrium.

The Hardy-Weinberg principle asserts that allele frequencies in a population remain constant; for example, if 50% of people have blue eyes, then each successive generation will continue to have 50% of people with blue eyes as long as certain assumptions are met. The Hardy-Weinberg equilibrium assumes that within a population random mating occurs, no migration occurs, no mutations occur, no natural selection occurs, and the population is sufficiently large. If any of these assumptions are not met, the allele frequencies of the population will change, causing the population to evolve. For this question, all of the answer choices except "Random mutations" (remember there must be no mutations) are required assumptions for the Hardy-Weinberg equilibrium to be in effect.

Haploid cells contain one of each numbered chromosome, for a chromosome number of "n." Diploid cells contain two of each, so the number of chromosomes in a diploid cell is 2n, or twice the haploid number.

This question is essentially asking, "Which of the following is a point mutation of the original sequence?" A point mutation is a mutation in which one base pair of DNA is substituted for another. A point mutation will not change the reading frame of a DNA sequence because it does not involve adding or removing any bases. The only answer choice that is identical to the original sequence with the exception of one base pair being changed for another is 5'GATCACG3', so this is the correct answer.