#165 Summary of Genetic technology

 1 Gene technology involves altering the genes in an organism, which is then said to be genetically modifi ed.

 2 The usual way of genetically modifying bacteria is to insert a plasmid containing the desired gene into them.

#164 Social implications of GMO

There are social implications related to using genetically modified organisms in food production.

#163 Herbicide and insect resistant crops

Genetic technology can provide benefits in, for example, agriculture and medicine, but has the associated risk of the escape of the gene concerned into organisms other than the intended host.

#162 Genetically modified organisms

Genetic engineering is improving the quality (nutrition) and yield of crop plants and livestock  --> therefore is solving the demand for food in the world

#161 Gene therapy

Gene therapy: treatment of a genetic disorder by altering a person's genotype (insert functional alleles of genes into cells)

#160 Genetic screening

Genetic screening: analysis of a person's DNA to check for the presence of a particular allele
* available for adults, fetus, embryo,...

#159 Bioinformatics

Bioinformatics is the collecting, processing and analysis of biological information and data using computer software.

#158 Genetic markers and microarrays

Genetic markers uses enzymes that produces fluorescent substances. There used to be antibiotic resistance gene markers, but there was the chance that they would spread the antibiotic resistance to other new strains of bacteria.

#157 PCR and gel electrophoresis

The polymerase chain reaction (PCR) and gel electrophoresis both work with molecules. Both these procedures are needed for forensic science.

#156 Genetic engineering basics

Genetic engineering involves the manipulation of naturally occurring processes and enzymes.

#155 Genetic technology Syllabus 2016 -2048

19.1 Principles of genetic technology
19.2 Genetic technology applied to medicine
19.3 Genetically modified organisms in agriculture

#154 Summary Biodiversity and conservation

1 All living organisms may be classified into one of the five kingdoms: prokaryotes, protoctists, fungi, plants and animals.

2 Biodiversity includes the range of habitats (environments) and species in an area, and the genetic diversity within a species.

#153 International conservation and restoring degraded habitats

Non-governmental organisations, such as the World Wide Fund for Nature (WWF) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), play important roles in local and global conservation.

An important part of conservation is restoring degraded habitats so that they may support a flourishing community with high biodiversity.

#152 Controlling alien species

Alien or invasive species are those that have moved from one ecosystem to another where they were previously unknown.

#151 Assisted reproduction and problems of successful conservation

Assisted reproduction is a solution to the problem of inbreeding.

#150 Protecting endangered species

An endangered species is one that is threatened with extinction. The best way to conserve any species is to keep it in its natural habitat.

#149 The need to maintain biodiversity

For some people, the safety of biodiversity is simply a moral or ethical issue. For others it may be for ecological reasons, aesthetic reasons, social and commercial reasons or for other services.

#148 Threats to biodiversity

Biodiversity is under threat in many aquatic and terrestrial ecosystems as human population continues to increase and we take more resources from the environment and produce more waste.

#147 Classification

Classification is arranging different kinds of organisms into groups.

#146 Assessing species diversity

There are 2 types of sampling: random sampling and systematic sampling.

#145 Biodiversity

Biodiversity is much more than a list of all the species in a particular area.

#144 Biodiversity, classification and conservation Syllabus 2016 - 2018

18.1 Biodiversity
18.2 Classification
18.3 Conservation

#143 Summary of Selection and Evolution

1 Genetic variation within a population is the raw material on which natural selection can act. 

2 Meiosis, random mating and the random fusion of gametes produce genetic variation within populations of sexually reproducing organisms. Variation is also caused by the interaction of the environment with genetic factors, but such environmentally induced variation is not passed on to an organism’s off spring. The only source of new alleles is mutation. 

#142 Species and speciation

Isolating mechanisms can lead to the accumulation of different genetic information in populations, potentially leading to new species.

#141 Evolution and Extinction

General theory of evolution: organisms have changed over time.

#140 Artificial selection

Humans use selective breeding (artificial selection) to improve features in ornamental plants, crop plants, domesticated animals and livestock.

#139 Natural selection

Populations of organisms have the potential to produce large numbers of offspring, yet their numbers remain fairly constant year after year.

#138 Genetic variation

The variation that exists within a species is categorised as continuous and discontinuous. The environment has considerable influence on the expression of features that show continuous (or quantitative) variation.

#137 Selection and Evolution Syllabus 2016 - 2018

17.1 Variation
17.2 Natural and artificial selection
17.3 Evolution

#136 Summary of Inherited change

1 Meiosis consists of two divisions. The first division, meiosis I, separates the homologous chromosomes, so that each cell now has only one of each pair. The second division, meiosis II, separates the chromatids of each chromosome. Meiotic division therefore produces four cells, each with one complete set of chromosomes.

#135 Gene control in eukaryotes

Some genes are transcribed all the time to produce constituitive proteins; others are only 'switched on' when their protein products are required.

#134 Gene control in prokaryotes (lac operon)

In both prokaryotes and eukaryotes, transcription of a gene is controlled by transcription factors.

#133 Genetic mutations

A mutation is an unpredictable change in the genetic material of an organism.

#132 Genetic diagrams

Patterns of inheritance are explained by using genetic diagrams. Genetic diagrams are the standard way of showing the genotypes of offspring that might be expected from 2 parents.

#131 Terms for human genetics

Studies of human genetic conditions have revealed the links between genes, enzymes and the phenotypes.

#130 Meiosis

Meiosis involves two divisions, called meiosis I and meiosis II.

#129 Gametogenesis

Diploid organisms contain pairs of homologous chromosomes.

#128 Inherited Change Syllabus 2016 -2018

16.1 Passage of information from parent to offspring 
16.2 The roles of genes in determining the phenotype
16.3 Gene control

#127 Summary of Homeostasis and Co-ordination

 1 Animals and plants have internal communication systems that allow information to pass between different parts of their bodies, and so help them to respond to changes in their external and internal environments.

 2 Mammals keep their internal environment relatively constant, so providing steady and appropriate conditions within which cells can carry out their activities. This is known as homeostasis.

#126 Plant hormones - Gibberellin

Gibberellins are plant growth regulators that are synthesized in most parts of plants (mainly in young leaves and seeds and in stems). They have a role in seed germination and controlling stem elongation.

#125 Plant hormones - Auxin

Chemical communication in plants

Plant hormones or plant growth regulators are:
- produced in a variety of tissues
- move from cell to cell (by diffusion or active transport) or carried in xylem sap and phloem sap

The two types we're going to look at auxin and gibberellin.

#124 Venus fly trap

The Venus fly trap is a carnivorous plant that obtains a supply of nigtrogen compounds by trapping and digesting small animals, mostly insects.

#123 Birth control

‘Birth control’ means taking control over if and when a couple have a child. It may involve:
- contraception to prevent fertilisation
- use of hormones to prevent pregnancies

#122 Hormonal communication

Hormones like adrenaline, insulin, glucagion and ADH

- cell-signalling molecules
- made in endocrine glands; glands are groups of cells that secrete (produce and release) one or more substances
- passed directly into the blood

#121 Striated muscles

Striated muscles are muscles attached to the skeleton. They are neurogenic - they contract when stimulated to do so by impluses that arrive via motor neurones.

#120 Synapses

Synapse

- point where 2 neurones meet but do not touch
- contains the end of presynaptic neurone + synaptic cleft + end of postsynaptic neurone

#119 Action potentials

Action potentials are rapid changes in potential difference across the membrane.

#118 Control and co-ordination in mammals, the nervous system

Humans, like all living organisms, can respond to changes in the environment and so increase survival. Humans have 2 control systems to do this: the nervous system and the endocrine (hormonal) system. The human nervous system controls everything from breathing and standing upright, to memory and intelligence. It has 3 parts: detecting stimuli, coordinating and effecting a response.

#117 Control and co-ordination Syllabus 2016-2018

15.1  Control and co-ordination in mammals
15.2  Control and co-ordination in plants