Biology 40S Exam Review - Genetics

In a monohybrid cross, if a heterozygous organism is crossed with a homozygous recessive organism, what is the probability that their offspring will exhibit the recessive phenotype?

Which of these methods would be most suitable for determining if a plant with a dominant phenotype is homozygous dominant or heterozygous?

A cross between two organisms yields a 1:1 phenotypic ratio. Which of the following parental genotypes is most likely to generate this type of pattern?

If a purebred tall plant is cross-pollinated with a purebred short plant, and all offspring are tall, this is best explained by what concept?

Two organisms have the same physical characteristics for a trait. Which of the following conditions is most probable?

In a test cross, if the offspring display a 1:1 phenotypic ratio of dominant to recessive traits, what does this indicate about the genotype of the parent with the unknown genotype?

Based on the provided cross of two heterozygous plants for both traits (RrTt x RrTt), what is the probability of obtaining offspring with the genotype Rrtt?

In the given dihybrid cross (RrTt x RrTt), what is the combined probability of obtaining offspring that exhibit either the red and dwarf phenotype, or the yellow and tall phenotype?

Which of Mendel's laws explains the observation that during gamete formation, the parental alleles for a specific trait separate so that each gamete carries only one allele for that trait?

What proportion of the offspring from the cross of two dihybrid plants (RrTt x RrTt) are expected to be homozygous dominant for at least one of the two traits?

In the cross of Female A and Male A, what does the observed 1:1 phenotypic ratio of black to white offspring indicate about the parents' genotypes?

If a black offspring from the cross of Female A and Male A is crossed with a white individual, what is the probability of their offspring having the white phenotype?

In the cross of Female B and Male A, all offspring are black. What does this reveal about Female B's genotype?

Given the provided information, if a red flower plant (RR) was crossed with a white flower plant (WW) and the offspring produced pink flowers, what type of inheritance pattern is this?

In a scenario where red and white coat colors in cattle are both fully expressed (red and white hairs present), what type of genetic inheritance is demonstrated?

An autosomal dominant trait can be passed from a father to his son.

In sex-linked recessive inheritance, fathers will always pass the trait to their sons.

In an autosomal dominant inheritance pattern, an affected child must always have had at least one affected parent.

A sex-linked recessive trait will show up more commonly in females than in males.

Meiosis results in the production of four identical diploid gametes.

Crossing over occurs during Metaphase I of meiosis.

Random assortment during meiosis contributes to genetic variation by creating new gene combinations not seen in the parental cells.

The unique species of the Galapagos Islands are not useful for studying evolution.

Darwin's theory of natural selection was solely based on the work of Malthus

The concept of 'fitness' in biology refers only to an organism’s ability to survive in their habitat.

Lamarck is credited with the theory of natural selection.

Lyell's studies on geology supported the idea that the Earth was unchanging.

Malthus's work on population growth implied resources could infinitely sustain a population without limits.

Lamarck proposed the concept of 'use it or lose it' regarding the inheritance of traits.

Darwin and Lamarck both viewed the concept of change over time in a similar fashion.

Evolution always occurs at a constant rate, regardless of environmental stability.

Darwin was the first evolutionist.

The bottleneck effect is a type of genetic drift where allele frequencies change due to random chance regardless of population size.

Genetic drift leads to an increase in genetic variation within a small population because new alleles are introduced through random events.

Divergent evolution occurs when geographically separated populations of the same species experience similar selective pressures, causing them to become more alike over time.

Geographical isolation can lead to speciation because separated populations can no longer interbreed, this allows them to develop distinct characteristics that result in a new species

Giraffes developed longer necks solely due to environmental needs, without any other factors at play.

The process of natural selection resulted in shorter-necked giraffes having higher reproductive rates compared to the long neck giraffes

A giraffe that develops a longer neck during its lifetime will pass this acquired characteristic directly to its offspring.

Overpopulation is one contributing factor for causing competition for resources among giraffes.

5 neck variations occur in giraffes

The giraffe's ability to reach higher leaves is a structural adaptation that provides a survival advantage in a more competitive environment.

Use and disuse of the giraffe's claws directly led to them developing more pronounced claws over time.

The text describes a stabilizing selection, favouring average-length necks in the giraffe population.

The competition that exists in the giraffe population is mainly for water, not for food.

Once adaptation of a longer neck is achieved by a giraffe, other physical traits of the giraffe are always less likely to adapt further.

If the frequency of the recessive allele, q, is 0.32, then the frequency of the dominant allele, p, is 0.68.

The homozygous dominant phenotype frequency in the population, given p = 0.68, is approximately 46%.

In a population of 135 individuals, approximately 59 individuals will express the heterozygous trait if 2pq = 0.4352.

Natural selection is an active process that causes a disruption in genetic equilibrium.

Artificial selection occurs in a natural environment and does not purposely select specific traits.

The peppered moth is an example of artificial selection because humans selected moth colors for breeding.

Geographical distribution of species provides no evidence for the theory of evolution, and species are randomly distributed regardless of location.

The fossil record demonstrates that life on Earth remains static. There are no changes over time in response to environmental changes.

Homologous structures are body structures that are similar in form and function and are found only in similar species.

Similarities in the bone structure of a bat wing, whale flipper, horse leg, and human hand provide evidence against the notion of common ancestry.