Genetics: Genes, DNA, and Chromosomes

Which of the following accurately defines a gene?

What is the role of alleles in genetics?

Which scientist's work with X-ray diffraction significantly contributed to the discovery of DNA's double helix structure?

What type of bond links the two strands of a DNA molecule together?

During DNA replication, a sequence on one strand reads 'ATC'. What would be the corresponding sequence on the complementary strand?

What defines homologous chromosomes?

If a DNA triplet code is AGC, what type of molecule is directly determined by this sequence?

Which of the following is the only source of new alleles and genetic variation within a species?

A mutation in a skin cell is unlikely to have evolutionary consequences. Why?

Which type of point mutation results in a change to the reading frame of the genetic sequence?

Cystic fibrosis is caused by a deletion of three bases in the CFTR gene. What is the immediate consequence of this mutation at the protein level?

In sickle cell anaemia, a point mutation in the HBB gene causes a single amino acid change that affects the shape of red blood cells. What type of point mutation is responsible for this?

Why is sexual reproduction more beneficial than asexual reproduction in the long run for species survival?

What is the purpose of meiosis?

What process during meiosis leads to the exchange of genetic material between homologous chromosomes?

How does independent assortment contribute to genetic variation?

What is the definition of a gene pool?

What effect does immigration have on the genetic variation of a population?

What is the role of 'VARPA' in the context of natural selection?

Why is variation within a population crucial for natural selection?

What is genetic drift?

Why does genetic drift have a more significant impact on smaller populations?

What is the founder effect?

How can the founder effect impact the genetic variation of a population?

What is the bottleneck effect?

How does the bottleneck effect affect the genetic variation of a species?

Even if a population recovers in size after experiencing a bottleneck effect, why might it still be vulnerable?

A population of butterflies exhibits two distinct wing patterns: vibrant orange and subdued brown. A sudden volcanic eruption darkens the surrounding landscape with ash. Over several generations, the proportion of brown butterflies increases significantly. Which evolutionary mechanism is MOST likely responsible for this shift in wing pattern frequency?

Imagine a scenario where a hurricane devastates a small island inhabited by a lizard population. Only a few lizards survive, and by chance, these survivors possess a set of rare traits not representative of the original population. What is the MOST accurate description of the long-term evolutionary consequence?

In a remote island population of birds, a single bird with a unique beak shape arrives from the mainland. This beak shape allows it to access a previously untapped food source, leading to enhanced survival and reproduction rates compared to the native birds. Decades later, nearly all birds on the island possess this novel beak shape. Which evolutionary mechanisms BEST explains this scenario?

A researcher is studying a plant population on a remote island. They observe that the plants exhibit a wide range of flower colors, but a fungal disease suddenly wipes out most of the plants with red flowers. Over time, the population recovers, but the prevalence of red flowers remains very low. Which combination of evolutionary mechanisms likely explains this scenario?

What is the relationship between a gene and a protein?

Which component is NOT part of a nucleotide?

What type of bond holds complementary base pairs together in a DNA molecule?

What is the role of triplets in the genetic code?

What is the immediate result of a change in the sequence of amino acids in a polypeptide chain?

If a mutation occurs in a body cell, why isn't it inheritable?

Which type of mutation has the least impact on the resulting protein sequence?

If a substitution point mutation does not alter the amino acid sequence of the resulting protein. What is this known as?

A mutation in a gene shifts the reading frame and introduces a premature stop codon. What type of mutation is this considered?

Why is sexual reproduction considered a source of genetic variation?

What is the direct outcome of fertilization during sexual reproduction?

How does crossing over contribute to genetic variation?

During which phase of meiosis does independent assortment occur?

What is the significance of having half the number of chromosomes in gametes produced by meiosis?

Which field of biology specifically examines the allele frequencies within populations and how these change over time?

What is the term for the movement of alleles between different populations?

What is the difference between emigration and immigration?

What does 'VARPA' describe?

Within the VARPA framework, what is the role of 'selection pressure'?

What is the MOST likely consequence of a population having very limited genetic variation?

Which of the following describes genetic drift?

Why is genetic drift more pronounced in small populations?

What is the key characteristic of the founder effect?

Why might a new population established by the founder effect have limited genetic variation?

Which scenario BEST describes the bottleneck effect?

How does the bottleneck effect potentially affect a species' ability to adapt to future environmental changes?

A population of frogs is thriving in a stable wetland environment. A prolonged drought dramatically shrinks the wetland, leading to a significant reduction in the frog population. What is the MOST likely long-term consequence of this event?

In a population of wildflowers, some individuals produce fragrant flowers while others produce odorless flowers. Over several generations, the proportion of fragrant flowers decreases, while the proportion of odorless flowers increases. Which of the following scenarios is LEAST likely to explain the observed shift?

In a population of fish. Larger fish are better at defending territory but are more visible to predators. Smaller fish are harder to see but struggle to compete for resources. Over time, the population exhibits a stable distribution of both large and small fish sizes. Which mechanism maintains the variation?

A road construction project divides a population of rodents into two isolated groups. Over many generations, genetic differences accumulate between the two groups due to genetic drift and local adaptation. Eventually, when the road is removed, the two groups can no longer interbreed. Which of the following has occurred?

In a hypothetical scenario, a population of birds is subjected to strong directional selection favoring larger beak sizes due to a shift in the available food source towards larger seeds. After many generations, all birds in the population exhibit extremely large beaks. However, a sudden shift back to smaller seeds occurs. What is the MOST likely outcome?

Why is it essential to consider both genetic drift and natural selection when analyzing the evolution of small, isolated populations?

Considering the different mechanisms of evolution, which of these options will always result in adaptation?

How does understanding allele frequencies in a population help scientists?

Besides mutation, why is sexual reproduction important for promoting genetic variation?

The total collection of genes in a population at any one time is known as what?

What happens in gene flow?

According to 'VARPA', which option is genetically 'better suited' to the environment?

Imagine a scenario where a population of insects is exposed to a new pesticide. Initially, a small percentage of the population possesses a genetic mutation that confers resistance to the pesticide. After several generations of pesticide use, the vast majority of the insect population is now resistant. Which evolutionary mechanisms BEST explains this?

Genetic drift does NOT depend on which factor?

What is the underlying theme of genetics?

If a population gains individuals, what is MOST likely to happen to genetic variation?

If there are little to no phenotypes better suited than others, and 'VARPA' never occurs, what is MOST likely to happen?