Standard Grade Biology - Synopsis and Definitions

Biology is available at General and Credit levels only. The course is largely practical in content, the work being directed by clearly written booklets which are divided into topics and sub-topics.

The practical part of the course is assessed internally and accounts for 30% of the final mark. The Knowledge and Understanding and Problem Solving is assessed in a final examination at both credit and general levels.

1. The Biosphere

   habitat

   place where an organism lives

   population

   a group of organisms of one species

   community

   all organisms living in a habitat

   ecosystem

   community + habitat

   producer

   an organism that makes its own food (green plant)

   consumer

   organism that eats other organism

   herbivore

   organism that eats only plants

   carnivore

   organism that eats only animals

   omnivore

   organism that eats plants and animals

   competition

   when several organisms need the same resources

   pollution

   contamination of the environment by harmful substances

   indicator species

   species which, by its presence or absence, shows the level of a factor in the environment.

2. The World of Plants

   germination

   growth of a seed into a young plant

   pollination

   transfer of pollen from anther to stigma

   cross pollination

   transfer of pollen from anther to stigma of a different flower

   self pollination

   transfer of pollen from anther to stigma of the same flower

   insect pollination

   transfer of pollen from anther to stigma by insects

   wind pollination

   transfer of pollen from anther to stigma by wind

   fertilisation

   fusion of the male and female gametes

   fruit

   part of a plant containing seeds

   seed dispersal

   spread of seeds away from parent plant to prevent overcrowding

   sexual reproduction

   production of new individuals through fertilisation of male and female gametes

   asexual reproduction

   production of new individuals from a single parent without fertilisation

   clone

   genetically identical individual formed from a single parent

   photosynthesis

   the process by which green plants make their own food using light energy from the sun.

   limiting factor

   a factor which slows the rate of photosynthesis when in short supply

3. Animal Survival

   digestion

   process by which large insoluble food molecules are broken into smaller, soluble food molecules by enzymes in the gut

   absorption / assimilation

   process by which digested products pass through the gut wall into the blood

   peristalsis

   process by which circular muscles drive food along the gut

   internal fertilisation

   fusion of male and female gametes inside the female's body

   external fertilisation

   fusion of male and female gametes outside the female's body

   zygote

   single cell formed by the fusion of the male and female gamete

   implantation

   attachment of developing embryo to wall of uterus

   deamination

   breakdown of excess amino acids in the liver to form urea

   excretion

   removal of waste products of metabolism from the body

   circadian rythm

   one occuring on a daily basis

   annual rythm

   one occuring on a yearly basis

4. Investigating Cells

   diffusion

   movement of a substance from a high concentration to a low concentration until evenly spread

   osmosis

   movement of water from a high concentration of water (weak solution) to a low concentration of water (strong solution) through a selectively permeable membrane

   selectively-permeable

   allows certain molecules to pass through (small) but not others (large)

   concentration gradient

   difference in concentration between adjacent regions

   mitosis

   division of the nucleus into two daughter nuclei which are identical to each other and the parent nucleus

   catalyst

   a substance which speeds up the rate of a chemical reaction

   enzyme

   a protein which speeds up the rate of chemical reactions in cells, without itself being changed

   synthesis

   building up large molecules from small molecules

   degradation

   breaking down large molecules into several small molecules

   optimum condition

   the condition of pH or temperature at which an enzyme works best

   respiration

   process which releases energy in cells

   aerobic respiration

   release of energy in cells using oxygen

   anaerobic respiration

   releasee of energy in cells without using oxygen

   metabolism

   the sum of all the chemical reactions occuring in a cell

5. The Body in Action

   joint

   a place where two bones meet

   antagonistic

   when a pair of muscles work in opposition to each other

   breathing

   mechanical process in which air is moved in and out of the lungs

   haemoglobin

   iron-containing chemical which carries oxygen around the body

   reflex action

   rapid, automatic response to a stimulus, protecting the body from damage

   fatigue

   when a muscle tires due to build-up of lactic acid during strenuous exercise

   recovery time

   the time taken for either breathing rate / pulse rate / lactic acid levels to return to normal after exercise

6. Inheritance

   genotype

   number and type of genes an organism possesses

   phenotype

   appearance of an organism resulting from inherited characteristics

   gene

   part of a chromosome controlling one characteristic

   allele

   different form of a gene

   dominant

   allele that always shows itself in the phenotype

   recessive

   allele that is always masked by a dominant one

   true breeding

   organism with 2 dominant or 2 recessive alleles

   homozygous

   possessing 2 identical genes for a character

   heterozygous

   possessing 2 different genes for a character

   selective breeding

   choosing parents with desired characteristics to improve stocks

   mutation

   a change in the structure or number of chromosomes

   mutagenic agent

   something which causes a mutation

   amniocentesis

   sampling of amniotic fluid containing foetal cells to detect chromosomal abnormalities

7. Biotechnology

   biotechnology

   use of microbes to produce useful materials

   fermentation

   process carried out by yeast/bacteria in absence of oxygen; another term for anaerobic respiration

   sewage

   organic waste from humans

   upgrading

   conversion of waste products into useful products

   decay

   breakdown of dead organisms and wastes by microbes

   nitrification

   processes carried out by bacteria resulting in production of nitrate

   denitrification

   processes carried out by bacteria converting nitrates to nitrogen gas

   contamination

   presence of unwanted microbes in a culture

   genetic engineering

   removal of genes from one organism and insertion into another, allowing greater quantities of a product to be made faster and more cheaply

   biological detergent

   detergent containing protease / lipase enzymes from bacteria

   antibiotic

   chemicals which prevent the growth of bacteria

   immobilisation

   attachment of enzymes or microbes to a substance to hold them in place

N.B. - conformance testing is not yet complete

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