Natural Selection and Genetic Modification in Biology

What is the process of speciation?

1. Variation exists within a population due to genetic mutations. 2. Alleles providing survival advantages are selected for. 3. Populations can become isolated. 4. Different advantageous alleles may be selected in new environments. 5. Genetic variation increases between isolated populations. 6. A new species forms when they can no longer produce fertile offspring.

What does the term 'genetic variation' refer to in evolution?

The differences in alleles within and between populations.

What role do advantageous characteristics play in evolution?

They increase in frequency within a population over generations.

What is the relationship between natural selection and genetic mutations?

Natural selection acts on genetic mutations, favoring those that provide survival advantages.

What is the role of isolation in the speciation process?

Isolation can lead to different alleles being selected in separated populations.

What is the outcome when two populations can no longer breed to produce fertile offspring?

A new species has formed.

What is a strain in the context of bacterial reproduction?

A new variant of bacteria that arises due to mutations.

How does the reproduction rate of bacteria affect the emergence of resistance?

Bacteria reproduce quickly, allowing mutations to spread rapidly.

What is the significance of Darwin's knowledge of fossils in his theory?

It provided evidence for the evolution of species over time.

How do resistant bacteria support Darwin's theory of natural selection?

They have been selected by the environment for their advantageous feature of resistance, which aids in survival.

What is MRSA and why is it called a 'superbug'?

MRSA is a type of bacteria that is resistant to many different antibiotics, making it difficult to treat.

Where is MRSA commonly found and how does it spread?

MRSA is common in hospitals and spreads when healthcare workers move between patients.

What does fossil evidence indicate about the development of organisms?

Fossil evidence shows that developments arose slowly over time, which can be estimated using carbon dating.

Who is Ardi and what significance does she hold in human evolution?

Ardi, or Ardipithecus ramidus, is the oldest known human ancestor, estimated to have lived 4.4 million years ago, showing features of both humans and apes.

What does the bone structure of Ardi's feet suggest?

It suggests that Ardi and chimpanzees evolved separately rather than together.

What is the significance of Lucy in the study of human evolution?

Lucy, dating from 3.2 million years ago, represents an intermediate between apes and early humans, showing a mix of human-like and chimp-like features.

What was discovered by Louis and Mary Leakey in the 1950s?

They discovered fossils that supported the theory of natural selection, including remnants of stone tools and Homo habilis.

What are the characteristics of Early Stone Age tools used by Homo habilis?

They were basic pebble tools ('Oldowan tools') created by smashing rocks together, used for simple tasks like cracking nuts.

What advancements were made in Late Stone Age tools?

More advanced species like Homo neanderthalensis and modern Homo sapiens used pointed arrowheads, spears, and hooks for complex tasks like fishing.

What is radiometric carbon dating?

It estimates how long ago an organism lived by measuring the natural radioactive decay of Carbon-14.

How can archaeologists date stone tools using stratifying rock layers?

By examining the sediment layers where tools are found, they can date fossils within those layers to estimate the age of the tools.

What is a pentadactyl limb and its significance in evolution?

A pentadactyl limb has five digits and is found in various organisms, suggesting they share a common ancestor and evolved under different selection pressures.

What role does natural selection play in the evolution of antibiotic-resistant bacteria?

Natural selection favors bacteria that have mutations allowing them to survive antibiotic treatment, leading to an increase in resistant populations.

Why are new resistant bacteria a concern for public health?

They spread rapidly because people lack immunity and there are often no effective treatments available.

What does the presence of intermediate organisms like Ardi and Lucy indicate?

They provide evidence that natural selection and evolution occurred gradually over time.

What does the term 'superbug' refer to in microbiology?

It refers to bacteria that have developed resistance to multiple antibiotics, making them particularly difficult to treat.

How do fossil findings contribute to our understanding of human evolution?

They provide physical evidence of anatomical changes and the timeline of human ancestry.

What is the importance of stone tools in understanding human evolution?

They illustrate the progression of cognitive and motor skills as human brains evolved.

What is the significance of carbon dating in archaeology?

It allows researchers to estimate the age of fossils and artifacts, providing context for human evolution.

What evidence suggests that different species evolved due to varying environmental pressures?

The anatomical differences observed in species with pentadactyl limbs indicate adaptations to different environments.

How does the study of fossils help in understanding the process of evolution?

Fossils reveal the physical characteristics of organisms over time, showing gradual changes that support evolutionary theory.

What are the implications of finding remnants of stone tools with fossils?

They suggest the presence of early human-like behavior, such as tool-making, which is crucial for understanding human evolution.

What is the common pattern found in the limbs of humans and some animals like bats and birds?

Five digits (four fingers and a thumb)

What does the Five Kingdoms classification system categorize organisms into?

Animals, Plants, Fungi, Prokaryotes, and Protists.

What is the purpose of classifying organisms?

To understand the genetic relationships between species and organisms.

What is the binomial naming system based on?

The genus and species of an organism.

What are the three domains in the Three Domains system?

Archaea, Bacteria, and Eukaryota.

What type of organisms does the domain Archaea include?

Primitive bacteria that live in extreme environments.

What is selective breeding?

The process where humans choose which organisms to breed to produce offspring with desirable characteristics.

What are the steps involved in selective breeding?

Choose parents with desired characteristics, breed them, select offspring with desired traits, and repeat.

What is a potential problem of selective breeding?

It can lead to inbreeding, reducing the gene pool.

How does a reduced gene pool affect a species?

It increases the risk of extinction if the environment changes or a new disease appears.

Why is inbreeding particularly concerning in domesticated animals?

It leads to a higher frequency of genetic defects due to a small gene pool.

What is tissue culture?

A method of culturing living tissue outside of the organism within a growth medium.

How can tissue culture be beneficial for plants?

It allows for the production of an entire field of identical cloned crops from a small cutting.

Can tissue culture be used for animal and human tissues?

Yes, it can be used to culture animal and human tissues outside of the body.

What is one economic risk associated with selective breeding in crops?

A disease could spread rapidly and destroy the entire population of crops.

What is the impact of a small gene pool on genetic conditions?

It increases the likelihood of recessive genetic defects appearing in offspring.

What is the classification of humans in the Five Kingdoms system?

Humans belong to the Animal kingdom, phylum Chordata, class Mammalia, and order Primate.

What advancements led to the development of the Three Domains system?

Improvements in microscopy and biochemistry, such as RNA sequence analysis.

What organisms are included in the Eukaryota domain?

Organisms with a nucleus enclosed in membranes, including protists, fungi, plants, and animals.

What is one example of a desirable characteristic in selective breeding?

Animals bred for more meat or plants bred for disease resistance.

What is the significance of Carl Woese in biological classification?

He proposed the Three Domains system, adding domains above kingdoms.

What is the risk of selective breeding for farmers?

Economic problems due to crop failure from disease affecting genetically similar plants.

What is the role of a growth medium in tissue culture?

It supports the growth of living tissue outside the organism.

What is the first step in the tissue culture process for cloning plants?

Select a plant with desirable characteristics and remove tissue from a fast-growing region, such as the root or shoot tip.

What technique is essential for maintaining sterile conditions during tissue culture?

Aseptic technique.

What happens to the tissue after it is placed on a growth medium in tissue culture?

It develops shoots and roots before being transferred to compost for further growth.

What is one benefit of tissue culture in agriculture?

It produces many offspring with specific desirable features.

What is a major risk associated with tissue culture?

The gene pool is reduced, leading to low diversity and increased vulnerability to diseases.

What is a potential consequence of cloning plants?

Clones may have a low survival rate and can exhibit genetic problems.

How can tissue culture benefit endangered species?

It can help in the preservation or even revival of extremely endangered or extinct species.

What is genetic engineering?

Modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.

What are two applications of genetic engineering in plants?

Engineering for disease resistance and producing larger fruits.

How are bacterial cells used in genetic engineering?

They are engineered to produce substances useful to humans, such as human insulin.

What is the role of restriction enzymes in genetic engineering?

They cut genes from chromosomes and also cut the vector into which the genes will be placed.

What is the purpose of ligase enzyme in the genetic engineering process?

It attaches the sticky ends of the gene and the vector together to produce a recombinant gene product.

Where is the vector placed in the genetic engineering process?

In another organism at an early stage in development.

What type of cells are targeted in plants for genetic modification?

Meristematic cells, which are unspecialized cells.

What is one advantage of genetically modified (GM) crops?

They are engineered to be resistant to insects and herbicides, resulting in increased yields.

What is gene therapy in the context of genetic engineering?

Transferring normal genes into patients to produce correct proteins and potentially cure inherited disorders.

What is a perceived risk of GM crops on the environment?

GM crops could affect wild flowers and insects, leading to reduced biodiversity.

What is a concern regarding the health effects of GM crops?

There is worry that the effects of GM crops on human health are not fully understood.

How can genetic engineering improve agricultural yields?

By improving growth rates and introducing modifications for different environmental conditions.

What is a potential ethical concern related to genetic engineering in humans?

It may lead to the possibility of designer babies.

What is a consequence of using herbicides and pesticides on GM crops?

It can kill insects and other plants, reducing biodiversity.

What is a risk associated with the spread of infertile GM crop genes?

These genes could spread to wild plants, leading to infertility in other species.

What is a potential ecological consequence of genetic engineering in agriculture?

It could create selection pressure, leading to increased resistance in other species, resulting in super weeds and pests.

What is the role of Bt crops in agriculture?

Bt crops use genes from the bacteria Bacillus thuringiensis to produce toxins that kill insect larvae, increasing insect resistance and crop yields.

How are genes from Bacillus thuringiensis introduced into crops?

Genes are cut out using restriction enzymes and re-inserted into the crop using ligase.

What are the potential human health concerns associated with Bt crops?

There are concerns about the unknown effects of the toxin produced by Bt crops on human health.

What environmental impact can result from the use of Bt crops?

Killing insects can lead to a loss of biodiversity, affecting the entire ecosystem.

What are the benefits of using fertilizers in agriculture?

Fertilizers provide nutrients like nitrates and phosphates, making plants more resistant and allowing them to grow faster and larger.

What is a potential downside of excessive fertilizer use?

Excess fertilizer can run off into rivers, killing fish and wildlife, and affecting biodiversity.

What is biological control in agriculture?

Biological control is the use of certain species to manage the population of other species, such as using Aphelinus abdominalis wasps to control aphid populations.

What are some perceived benefits of genetic engineering in agriculture?

Genetic engineering can improve crop yields, enhance growth rates, and allow crops to thrive in different environmental conditions.

What are some perceived risks of genetic engineering?

GM crops could affect wild plants, spread infertility genes, reduce biodiversity, and there are concerns about their effects on human health.

What is a potential ethical concern regarding genetic engineering in humans?

Genetic engineering in agriculture could lead to genetic engineering in humans, raising issues about designer babies.

What is a benefit of selective breeding in agriculture?

Selective breeding can greatly increase the yield of crops by selecting individuals that produce higher quality or larger food mass.

What is a disadvantage of selective breeding?

Selective breeding can lead to health problems in offspring, such as chickens bred for more meat being too large to walk.

What is a risk associated with lack of genetic variation in selectively bred populations?

If a selectively bred population is susceptible to a new disease, the entire population could be wiped out.

What ethical issues are associated with selective breeding?

Many consider it unethical to breed for desired characteristics if it results in suffering or reduced quality of life for the offspring.

How can genetic engineering help address world hunger?

By increasing crop yields, genetic engineering can contribute to solving world hunger, which is exacerbated by population growth.

What modifications can be introduced to crops through genetic engineering?

Modifications can allow crops to grow in hotter or drier climates, produce their own pesticides or herbicides, and contain extra vitamins.

What selection pressure do GM crops pose?

GM crops can create selection pressure that may lead to increased resistance in other species, resulting in super weeds and pests.

What is the significance of the bacteria Bacillus thuringiensis in agriculture?

Bacillus thuringiensis produces toxins that are utilized in genetically modified crops for insect resistance.

What is the impact of biological control on biodiversity?

Biological control can reduce biodiversity, which may have knock-on effects across the ecosystem.

What is the function of ligase in genetic engineering?

Ligase is used to re-insert cut genes into the crop's DNA.

How does the use of herbicides and pesticides affect biodiversity?

The use of herbicides and pesticides can kill insects and other plants, leading to reduced biodiversity.