Higher Biology Unit 3

Allele

One of several different forms of a gene.

Animal welfare

Physical and psychological well-being of animals. The term animal welfare assessed using behavioural indicators

Annual weed

Plant which grows, flowers, set seeds and dies within the space of one year.

Anthropomorphism

The tendency to attribute to animals human qualities such as mental, social and emotional characteristics.

Artificial selection

Where humans select organisms with desirable characteristics and breed them together, ultimately to produce a true breeding population.

ATP

Adenosine triphosphate, coenzyme used as an energy carrier in the cells of all known organisms

Biodiversity

Degree of variation of life forms within a given species, ecosystem, biome, or an entire planet.

Genetic diversity

The number and frequency of all alleles within a population.

Species diversity

Comprises the number of different species within an ecosystem and and the proportion of each species within the ecosystem.

Ecosystem diversity

Refers to the number of distinct ecosystems within a defined area.

Overexploitation

Where populations are reduced to a low level but may still recover.

Bottleneck effect

A random event in which a significant percentage of a population or species is killed or prevented from reproducing. This may cause small populations to lose genetic diversity.

Calvin cycle

A series of biochemical reactions that takes place in the chloroplast and does not require light.

Chlorophyll a and b

The green pigments which are found in almost all plants and green algae. They absorbs light which is essential for photosynthesis.

Competition

An interaction or struggle between organisms or species for a resource such as food, territory or mates, in which the fitness or numbers of one is reduced by the presence of another.

Cooperative hunting

Animals such as lions hunt as a group to increase their chances of successfully killing prey.

Extinction

The complete loss of a species from the planet.

Food security

The ability of human populations to access food of sufficient quality and quantity.

Habitat fragmentation

The clearing of habitats leaving only isolated patches of the old habitat remaining.

Habitat corridor

Allows movement of animals between habitat fragments

Fungicide

A chemical compound or biological organism used to control fungal diseases

Genetic diversity

Comprises the genetic variation represented by the number and frequency of alleles in a population.

Genome

The entirety hereditary information of an organism encoded in its DNA.

Genotype

A statement of an organism's alleles for a particular characteristic usually given as symbols.

Herbicide

A chemical compound used to kill weeds.

Heterozygote

Having two different alleles for a characteristic - a pea plant heterozygous for petal colour has two different petal colour alleles Cc.

Hierarchy

An organisation arranged in a graded order with member(s) at the top who are dominant over subordinate individuals.

Homozygote

Having two identical alleles for a characteristic - a pea plant homozygous for petal colour has two identical petal colour alleles, both pink (CC) or both white (cc).

Inbreeding

selected related plants or animals are bred for several generations until population breeds true for desired characteristics.

Inbreeding depression

Increase in frequency of individuals homozygous for recessive deleterious alleles. These individuals do less well at surviving to reproduce.

Insecticide

A chemical compound used to kill insect pests.

Invasive species

Naturalised species that spread rapidly and eliminate native species.

Introduced species

Species humans have moved either intentionally or accidentally to new geographic locations.

Light reaction

The photosynthetic process in which solar energy is harvested and transferred into the chemical bonds of ATP; can occur only in light.

Misdirected behaviour

Abnormal behaviour which the animal directs at another object, animal or human.

NADP

Coenzyme which is used to carry hydrogen (as NADPH) to chemical reactions which require a reducing agent.

Naturalised species

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Pecking order

A natural hierarchy in a group of birds, such as domestic fowl.

Perennial weed

A plant which lives for more than two years.

RuBisCO

Enzyme involved in the Calvin cycle that catalyzes the first major step of carbon fixation.

Stereotypic behaviour

Repetitive or ritualistic movement, posture, or utterance, found in animals with welfare problems.

Stroma

Part of the chloroplast where the Calvin cycle / Carbon fixation takes place.

Taxonomic group

The classification of organisms into sets based on similarities of structure, origin etc.

Trophic level

The position or stage an organism occupies in a food chain.

Carotenoids

Light absorbing pigments in leaves which extend the range of wavelengths absorbed

Photolysis

Process which splits water into oxygen, which is evolved, and hydrogen ions, which are transferred to co-enzyme NADP

Carbon Fixation Stage

AKA Calvin Cycle. Stage of photosynthesis during which RuBisCo fixes CO2 by attaching it to ribulose bisphosphate

RuBisCo

Enzyme that fixes carbon dioxide by attaching it to RuBP

RuBP

Ribulose bisphosphate - CO2 acceptor in Calvin cycle.

3PG

3-Phosphoglycerate: formed after addition of CO2 to RuBP in the the Calvin Cycle.

G3P

Glyceraldehyde-3-phosphate - used to regenerate RuBP and for the synthesis of glucose

Biosynthetic pathways

Lead to formation of a variety of metabolites such as DNA, protein and fat.

Plant field trials

are carried out in a range environments to compare the performance of different cultivars or treatments and to evaluate GM crops

Selection of treatments

to ensure valid comparisons

Number of replicates

take account of the variability within the sample

Randomisation of treatments

to eliminate bias when measuring treatment effects

Cross breeding

individuals from different breeds are bred to produce a population with improved characteristics

Increased vigour (hybrid vigour)

increased disease resistance or growth rate

Cultural methods

Ploughing, weeding and crop rotation

Selective herbicides

Have greater effect on broad-leaved weeds. Means they can be used on (narrow-leaved) arable crops.

Systemic herbicide

Spreads through vascular system of plants and prevents regrowth.

Systemic insecticides, molluscicides and nematicides

Spread through the vascular system in plants and kill pests feeding on the plants

Bioaccumulation

The build up of a chemical in an organism

Biomagnification

An increase in the concentration of a chemical moving between trophic levels.

Biological control

Where a pest is controlled using a natural predator, parasite or pathogen of the pest

Integrated Pest Management (IPM)

A combination of chemical, biological and cultural control methods.

Apathy

Very low level of activity - an indicator of poor animal welfare

Hysteria

Very high level of activity - and indicator of poor animal welfare.

Symbiosis

A co-evolved, intimate relationship between members of two different species

Parasitism

Where the parasite benefits in terms of energy or nutrients, whereas the host is harmed by the loss of these resources

Mutualism

Where both mutualistic partner species benefit in an interdependent relationship

Social hierarchy

a rank order within a group of animals consisting of dominant and subordinate members

Appeasement behaviour

behaviour carried out by subordinate animals to appease a dominant individual and reduce conflict

Ritualistic threat display

behaviour such as body posture, raised hackles and baring teeth, used instead of physical aggression

Altruistic behaviour

Behaviour that harms the donor but benefits the recipient

Reciprocal altruism

Where the roles of donor and recipient often reverse, often occurs in social animals.

Kin selection

Altruistic behaviour where the donor and recipient are closely related. The donor benefits in terms of increased chances of survival of shared genes in the recipient's offspring or future offspring.

Social insects

Bees, wasps, ants and termites