B14 Evolution and Variation Flashcards
What is environmental variation?
Differences between individuals due to the environment they live in, such as scars from accidents.
How can environmental conditions affect genetically identical plants?
Different conditions like light and mineral ions can result in plants that do not look identical, with deprived plants being smaller and weaker.
How can scientists investigate the effects of the environment on variety?
By using genetically identical plants or animals and placing them in different environmental conditions.
What is the significance of studying genetically similar animals in scientific research?
It helps scientists understand how environmental factors affect physical traits and behaviors.
What is genetic potential?
The maximum development an organism can achieve based on its genetic makeup, influenced by environmental conditions.
Variation may be?
Genetic or environmental
What does the theory of evolution by natural selection state?
It states that all species of living things have evolved from simple life forms that first developed over 3 billion years ago.
How do mutations contribute to evolution?
Mutations occur continuously, and very rarely, a mutation leads to a new phenotype. If the new phenotype is suited to an environmental change, it can lead to a relatively rapid change in the species.
What is a mutation?
A mutation is a change in the DNA sequence that can lead to new phenotypes.
What is speciation?
Speciation is the formation of new and distinct species in the course of evolution.
What is the role of environmental change in evolution?
Environmental changes can create conditions where new phenotypes are advantageous, leading to rapid changes in a species.
What is natural selection?
Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring.
What is an example of speciation?
The divergence of Darwin’s finches in the Galápagos Islands, leading to different species adapted to various ecological niches.
What is selective breeding?
where humans breed plants and
animals for desired characteristics.
What are problems with selective breeding?
defects in some
animals due to lack of variation.
What are the principles of genetic engineering?
Enzymes are used to isolate and’cut out’the required gene from an
organism, for example, a person.
The gene is then inserted intoavector using more enzymes. The
vector is usually a bacterial plasmid or a virus.
The vector is then used to insert the gene into the required cells,
which may be bacteria, animal, fungi, or plants (Figure 1).
Genes are transferred to the cells at an early stage of their
development (in animals, the egg, or very early embryo). As the
organism grows, it develops with the new desired characteristics
from the other organism. In plants, the desired genes are often
inserted into meristem cells which are then used to produce
identical clones of the genetically modified plant.
What is genetic engineering?
Genetic engineering involves changing the genetic material of an organism by isolating and inserting specific genes into its genome.
What are GM crops?
Genetically modified crops are plants that have had their genes altered through genetic engineering to exhibit desired traits.
What are some benefits of GM crops?
Increased yields, resistance to pests and herbicides, improved nutritional value, and ability to withstand environmental stresses like flooding.
What is the role of genetic engineering in human health?
Genetic engineering can help develop treatments for genetic disorders and improve the nutritional content of food crops.
What are the ethical considerations of genetic engineering?
Ethical considerations include the potential for unintended environmental impacts, food safety concerns, and the moral implications of modifying organisms.
What is tissue culture in plant cloning?
Tissue culture is a modern cloning method that uses plant hormones to grow thousands of new plants from a small piece of plant tissue. Plantlets are produced by stimulating callus cells with a different mixture of hormones and conditions to form tiny new plants.
It allows the production of thousands of identical plants with desired characteristics and helps preserve rare plant species.
What is a callus?
A callus is a mass of identical plant cells formed from a small group of cells treated with plant hormones.
What is embryo cloning in cattle?
Embryo cloning involves splitting early-stage embryos into multiple identical embryos, which are then transplanted into surrogate mothers.
It allows a high-quality cow to produce many more calves than through natural reproduction, improving breeding efficiency.
What is adult cell cloning?
Adult cell cloning involves creating a new animal by inserting the nucleus of an adult cell into an empty egg cell and stimulating it to develop.
What are the steps in adult cell cloning?
The nucleus is removed from an unfertilised egg cell.
At the same time, the nucleus is taken from an adult body cell, for
example, a skin cell of another individual of the same species.
The nucleus from the adult cell is inserted in the empty egg cell.
The new egg cell is given a tiny electric shock, which stimulates it to
start dividing to form embryo cells. These contain the same genetic
information as the original adult.
When the embryo has developed into a ball of cells, it is inserted into
the womb of an adult female to continue its development.
What is the difference between embryo cloning and adult cell cloning?
Embryo cloning involves splitting early embryos, while adult cell cloning uses the nucleus of an adult cell to create a new organism.
What are the ethical considerations of cloning?
Ethical considerations include animal welfare, the potential for misuse, and the implications of creating genetically identical organisms.
Ethical considerations include animal welfare, the potential for misuse, and the implications of creating genetically identical organisms.
Tissue culture can produce thousands of plants from a small tissue sample, ensuring genetic uniformity and scalability.
Advantages of genetic engineering in Agriculture:
improved growth rates of plants and animals
increased food value of crops, as genetically modified (GM) crops
usually have much bigger yields than ordinary crops
crops can be designed to grow well in dry, hot, or cold parts of
the world
crops can be engineered to produce plants that make their own
pesticide or are resistant to the herbicides used to control weeds.
