Ethics
What is the study of ethical issues arising from advances in biology, medicine and biotechnology called?
Bioethics.
What are the three main types of adaptations?
Structural, physiological and behavioural.
What is an alternative form of a gene called?
An allele.
What type of reproduction involves only one parent and generally produces genetically identical offspring?
Asexual reproduction.
What interaction occurs when two different species both benefit from their relationship?
Mutualism (+/+).
Which ethical approach focuses on producing the greatest good and the least harm?
The consequences-based approach.
Are animals that rely on external heat sources to regulate their body temperature called ectotherms or endotherms?
Ectotherms.
What is the difference between homozygous and heterozygous?
Homozygous means having two identical alleles for a gene; heterozygous means having two different alleles.
What is the name of asexual reproduction in which a new organism develops from an outgrowth on its parent, as seen in some plants?
Budding.
What is the ecological relationship in which one species benefits while the other is neither helped nor harmed?
Commensalism (+/0).
What is the difference between beneficence and non-maleficence?
Beneficence involves maximising benefits, while non-maleficence involves minimising harm.
Why do animals in hot climates, such as fennec foxes, benefit from having large ears?
Large ears increase surface area relative to volume, allowing more heat to be lost to the surroundings.
Two parents are heterozygous (Bb) for a trait where B is dominant. What is the probability of an offspring having the recessive phenotype?
25%, or 1 in 4. The offspring must inherit bb.
How many chromosomes are present in a human sperm cell, and how many are present in the zygote after fertilisation?
23 chromosomes in sperm and 46 chromosomes in the zygote.
What is the difference between interspecific and intraspecific competition?
Interspecific competition occurs between different species; intraspecific competition occurs between members of the same species.
A scientist refuses to falsify research results, even though doing so would benefit their career. Which ethical concept are they demonstrating, and why?
Integrity, because the scientist is acting honestly and prioritising the accurate representation of facts.
How does countercurrent heat exchange in penguins' feet help them survive in cold environments?
Warm arterial blood transfers heat to cooler venous blood returning from the feet, reducing heat lost to the environment and helping conserve body heat.
How does DNA methylation typically affect gene expression?
Methyl groups attach to DNA, generally reducing transcription and potentially silencing the gene, so less protein is produced.
Why does sexual reproduction generally produce more genetic variation than asexual reproduction?
Meiosis produces different allele combinations through crossing over and independent assortment. Random fertilisation then combines genetic material from two gametes.
What is a keystone species, and why can removing one destabilise an ecosystem?
A species that plays a critical role in maintaining ecosystem structure and function. Removing it disrupts interactions and population sizes, potentially causing major changes throughout the ecosystem.
A cloning technology could help treat serious diseases, but it is extremely expensive and only available to wealthy individuals. Identify two ethical concepts involved and explain how they apply.
Beneficence: the technology could improve health and provide benefits. Justice: unequal access may be unfair and disadvantage people who cannot afford it. Other well-justified concepts may also be accepted.
Industrial pollution darkens trees, making dark peppered moths harder for predators to detect than light moths. Explain how natural selection would affect the population over several generations.
Dark moths are better camouflaged, so they are less likely to be eaten. They survive and reproduce more successfully, passing on their alleles. Over generations, alleles associated with dark colour become more common.
Identical twins have the same DNA but develop different phenotypes as they age. Explain how epigenetics can account for this without altering their DNA sequences.
Different environmental exposures can produce different epigenetic modifications, such as DNA methylation and histone modifications. These alter transcription, changing the amounts of mRNA and protein produced, leading to different phenotypes despite identical DNA sequences.
In somatic cell nuclear transfer (SCNT), describe the process used to produce a cloned animal, from the donated cells to embryo implantation. (Basically describe the process of SCNT)
Remove the nucleus from a donated egg cell (enucleation). Extract the nucleus from a somatic cell and insert it into the enucleated egg. Stimulate the cell to divide into an embryo, then implant it into a surrogate mother.
In the food chain: shark → tuna → mackerel → small fish → shrimp, predict how removing sharks could affect tuna, mackerel and small fish populations. Explain the sequence.
Tuna increase because fewer sharks eat them. More tuna consume more mackerel, causing mackerel to decrease. With fewer mackerel eating them, small fish may increase.