Biology Reproduction and Genetics Overview

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Questions and Answers

What is a consequence of breeding closely related individuals?

Improvement in physiological traits

Higher reproductive rates

Increase in genetic diversity

Reduction of the gene pool (correct)

Why could a species with a small gene pool become extinct?

They reproduce at a slower rate.

They are more susceptible to environmental changes. (correct)

They have too many beneficial mutations.

They develop more genetic variation.

What is one of the first steps in genetic engineering?

Combining multiple genomes together

Using restriction enzymes to cut genes (correct)

Introducing a new organism into the environment

Reproducing bacterial cells asexually

What is the purpose of using sticky ends in genetic engineering?

To facilitate the joining of DNA fragments Signup and view all the answers

What role do antibiotic markers play in genetic engineering?

To identify engineered cells Signup and view all the answers

What is gene therapy primarily aimed at treating?

Inherited disorders Signup and view all the answers

Which of the following is an application of genetically modified crops?

Resistance to insects and herbicides Signup and view all the answers

What is a potential problem associated with a reduced gene pool?

Higher occurrence of genetic defects in offspring Signup and view all the answers

What is the primary advantage of asexual reproduction in plants?

It allows reproduction even when conditions are unfavorable. Signup and view all the answers

How do fungi contribute to their reproduction process?

They can produce spores both sexually and asexually. Signup and view all the answers

What structural formation does DNA take in the nucleus?

Double helix. Signup and view all the answers

What is the genome of an organism?

All the genetic material coding for proteins. Signup and view all the answers

Which of the following best describes a gene?

A small segment of DNA coding for specific amino acids. Signup and view all the answers

What is the role of pollen in the reproductive process of flowering plants?

To facilitate pollination and produce seeds. Signup and view all the answers

Which type of reproduction do strawberry plants primarily use?

Asexual reproduction through runners. Signup and view all the answers

What is a nucleotide in the context of DNA?

The basic building block of DNA. Signup and view all the answers

What is the primary mechanism behind Darwin's theory of evolution?

Natural selection based on environmental fitness Signup and view all the answers

Which of the following concepts contradicts Darwin's theory of evolution?

Inheritance of acquired characteristics Signup and view all the answers

What process leads to the increase in the frequency of advantageous alleles in a population?

Natural selection favoring advantageous traits Signup and view all the answers

Why was there controversy surrounding Darwin's ideas?

They contradicted religious beliefs about creation Signup and view all the answers

What is speciation?

The development of a new species from existing species Signup and view all the answers

Which statement correctly describes Darwin's contribution to evolutionary theory?

He provided a scientific framework that included natural selection. Signup and view all the answers

What concept did Jean-Baptiste Lamarck advocate that differs from Darwin's theory?

Traits acquired during an organism's lifetime can be inherited Signup and view all the answers

What evidence supported Darwin's theory post-publication?

Genetic evidence linking mutations to advantageous traits Signup and view all the answers

What occurs when bacteria reproduce and mutations occur?

New strains of bacteria can develop Signup and view all the answers

What is the consequence of using antibiotics to treat viral infections?

Bacteria may develop resistance Signup and view all the answers

Why is MRSA referred to as a 'superbug'?

It is resistant to multiple antibiotics Signup and view all the answers

What can result from failing to complete a course of antibiotics?

Some bacteria may survive and mutate Signup and view all the answers

How can the transmission of antibiotic-resistant bacteria be slowed in hospitals?

By maintaining high hygiene standards Signup and view all the answers

What is a major challenge in developing new antibiotics?

The process is time-consuming and expensive Signup and view all the answers

What should be avoided to reduce the development of antibiotic resistance in agriculture?

Using antibiotics for livestock disease prevention Signup and view all the answers

Which method is NOT recommended to control the spread of antibiotic-resistant bacteria?

Allowing unrestricted access of visitors in hospitals Signup and view all the answers

What is the first step in the process of speciation?

Variation exists within a population. Signup and view all the answers

Why did Alfred Russel Wallace receive less credit for the theory of evolution?

Darwin's publication overshadowed his contributions. Signup and view all the answers

What role do alleles play in natural selection?

Alleles providing a survival advantage are selected for. Signup and view all the answers

What did Gregor Mendel's experiments on pea plants primarily demonstrate?

Offspring inherit characteristics based on dominant and recessive units. Signup and view all the answers

What is a potential consequence of populations becoming isolated?

They may evolve differently over time. Signup and view all the answers

Which of the following statements about alleles is true?

Each parent contributes one allele to the offspring. Signup and view all the answers

What does the term 'fertile offspring' refer to in the context of speciation?

Offspring capable of reproducing with any population. Signup and view all the answers

What is the significance of warning coloration in animals according to Wallace's studies?

It serves as a defense mechanism. Signup and view all the answers

Study Notes

Reproduction

Many species of fungi can reproduce both sexually and asexually.
Asexual reproduction produces spores which are genetically identical.
Sexual reproduction increases variation and avoids extinction.
Strawberry plants reproduce asexually by producing runners.
Daffodils reproduce asexually by growing new bulbs from the main bulb.
Plants can reproduce asexually even if their flowers have been destroyed.

DNA and The Genome

The genetic material in the nucleus of a cell is composed of DNA.
DNA is a polymer made up of two strands twisted to form a double helix.
DNA is contained within chromosomes in the nucleus.
A gene is a section of DNA that codes for a specific protein.
The genome is all the genes coding for all the proteins in an organism.
The study of the human genome helps understand gene-disease links, inherited disorder treatments, and human migration patterns.

Understanding Genetics

DNA stands for deoxyribonucleic acid and it is a polymer that contains instructions for the body.
Chromosomes are structures made up of long molecules of DNA found in the nucleus of a cell.
DNA is made up of many small parts called nucleotides.
Breeding those with similar desirable characteristics leads to a reduction in the gene pool.
This reduces the number of different alleles, making the species vulnerable to environmental changes or disease.
A small gene pool increases the chance of genetic defects presenting in offspring.

Genetic Engineering

Genetic engineering involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.
Plant cells have been engineered for disease resistance or larger fruits.
Bacterial cells have been engineered to produce substances useful to humans, such as human insulin.
The process of genetic engineering involves:
- "Cutting out" genes using restriction enzymes, which creates "sticky ends".
- Cutting a virus or bacterial plasmid using the same restriction enzyme to create sticky ends.
- Joining the gene and loop with DNA ligase enzymes.
- Placing the combined loop in a vector, such as a bacterial cell.
- Identifying bacteria resistant to antibiotics, as these will be producing the modified gene.
In plants, the vector is placed in meristematic cells which creates identical copies of the modified plant.
Genetically modified crops can be resistant to insects and herbicides which can increase yield by reducing crop death.
Gene therapy uses genetic engineering to transfer normal genes into patients to correct faulty proteins.

Theory of Evolution

Charles Darwin, a scientist and naturalist, put forward the theory of evolution.
Darwin's theory is supported by experimentation, geology, and discovery of fossils.
Darwin's theory states that:
- Variation exists within species due to DNA mutations.
- Organisms best suited to the environment are more likely to survive and reproduce.
- Beneficial characteristics are passed on to the next generation.
- The frequency of advantageous alleles increases in the population over time.
Darwin's theory contradicted the idea of God being the creator of all species.
The mechanism of inheritance and variation was not known at the time.
Jean-Baptiste Lamarck believed that changes during an organism's lifetime were inherited by offspring.
Lamarck's theory was proven wrong when it was understood that environmental changes are not passed on through sex cells.
Darwin's theory was supported by genetics as it provided an explanation for the inheritance of beneficial characteristics.
Fossil evidence shows how developments in organisms arose slowly.

Speciation

Speciation is the process of a new species developing through the selection of different alleles.
Alfred Russel Wallace developed the theory of speciation, and therefore evolution by natural selection.
Wallace believed that individuals without characteristics for survival would die out.
Wallace and Darwin published joint studies, although Darwin received more recognition for the theory.
The process of speciation involves:
- Variation within a population due to genetic mutations.
- Natural selection of alleles providing a survival advantage.
- Isolation of populations, for example by physical barriers.
- Different alleles becoming advantageous in a new environment.
- Increased genetic variation over time between populations.
- The inability to interbreed to produce fertile offspring, which signifies a new species.

Gregor Mendel

Gregor Mendel trained in mathematics and natural history.
Mendel observed characteristics inherited by plants in monastery gardens.
Mendel performed breeding experiments on pea plants to observe inheritance.
Mendel concluded:
- Offspring inherit "hereditary units".
- One unit is received from each parent.
- Hereditary units can be dominant or recessive.

Resistant Bacteria

Bacteria are labelled resistant when they are not killed by antibiotics that were previously used as cures.
Mutations during reproduction can lead to new genes, such as the gene for antibiotic resistance.
Exposure to antibiotics creates a selection pressure, favoring bacteria with antibiotic resistance.
Antibiotic resistant bacteria reproduce and pass on the advantageous gene to their offspring, increasing the population.
Bacterial diseases spread rapidly because people are not immune to new resistant bacteria.
MRSA, a superbug resistant to many antibiotics, is common in hospitals.
Factors contributing to the development of antibiotic resistance:
- Prescribing antibiotics for viral or non-serious infections.
- Using antibiotics for specific bacteria.
- Not completing antibiotic courses.
- Overuse of antibiotics in agriculture.
Factors contributing to the transmission of antibiotic resistant bacteria include:
- Maintaining high standards of hygiene in hospitals.
- Regular hand-washing.
- Regular sterilisation of medical clothing.
It is difficult to keep up with the development of resistant strains due to slow and costly development of new antibiotics.

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Description

Explore the fascinating world of reproduction in fungi and plants, including asexual and sexual methods. Delve into the molecular structure of DNA and its role in genetics, including the human genome and its implications for health and disease. This quiz covers key concepts in reproduction and genetic science.