6 2 variation and evolution

Variation is defined as differences between individuals in an ecosystem.

Examples of genetic variation in humans include:

Environmental factors such as climate, diet, accidents, culture, and lifestyle contribute to environmental variation.

Examples of environmental variation include:

Genes give the characteristics we inherit, but the environment affects how these inherited characteristics develop. For example, children of tall parents have the genetic potential to be tall, but poor diet can affect their growth.

Genetic variation refers to differences in the DNA sequences of individuals within a population, leading to different traits or characteristics.

Genetic variation within a species is usually caused by mutations, which are random genetic changes that occur continuously.

Most mutations do not affect the phenotype because the protein produced by a mutated gene may function just as well as the protein from the non-mutated gene.

Mutations are random genetic changes that occur continuously.

The genome and its interaction with the environment influence the development of the phenotype of an organism.

Evolution is the change that occurs in populations over many generations. Natural selection is the mechanism by which this change occurs. This may result in the formation of a new species.

All species of living things have evolved from simple life forms that first developed more than three billion years ago.

Evolution has given rise to two new species at the point at which two populations of one species become so different in phenotype that they can no longer interbreed to produce fertile offspring.

Selective breeding in plants involves the intentional breeding of plants with desirable traits to produce offspring with enhanced characteristics.

Plants are selectively bred for various characteristics including: (The first two you need to specifically for your specification)

Selective breeding can lead to inbreeding, which occurs when closely related individuals are bred together to perpetuate desired traits. Inbreeding reduces the genetic diversity within a population, resulting in an increased risk of inheriting harmful genetic defects. Additionally, the reduced genetic variation makes organisms more susceptible to new diseases, as there are fewer chances of possessing resistance alleles within the population.

Animals are selectively bred for various characteristics, including: (The first two you need to know specifically for your specification)

Selective breeding (also known as artificial selection), involves the intentional mating of animals with desirable traits to produce offspring that inherit those characteristics. Through careful selection and breeding of animals over successive generations, breeders aim to develop new breeds or strains that reliably exhibit the desired characteristics.

Maintaining genetic diversity in selectively bred animal populations is crucial for :

False. Selective breeding occurs over many generations. Although, the process is much faster than natural selection as individuals with the desired characteristics are chosen to breed at the start of the process.

Genetic engineering is a process which involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.

The main steps in genetic engineering are:

Plant crops have been genetically engineered for several reasons, including to increase resistance to diseases or to produce bigger better fruits and vegetables.

Bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes.

The potential benefits of genetic engineering in agriculture and in medicine are:

The potential risks of genetic engineering in agriculture and medicine are:

Crops that have had their genes modified by introducing a gene from another organism are called genetically modified (GM) crops.

Tissue culture is using small groups of cells from part of a plant which is used to grow identical new plants.

Tissue culture is important to preserve rare plant species or for commercial benefit in nurseries.

A cutting is a method used by gardeners to produce many identical new plants from a parent plant. Part of a plant off is cut and used to grow a new genetically identical plant.

Embryo transplant is splitting apart cells from a developing animal embryo before they become specialised, then transplanting the identical embryos into host mothers.

The steps of adult cell cloning are: