Download B1 Biology Checklist Specification 2011

B1 Biology Checklist Specification 2011
Specification Point
B1.1.1 Diet and exercise
What makes up a healthy diet
Describe what each of the components are needed for in the body e.g. carbs for energy
Malnourishment is too much (obesity) or too little (e.g. starvation)
Deficiency diseases e.g. anorexia and diabetes type 2
The energy balance in the body and how diet and exercise can affect it
Metabolic rate varies according to exercise and genetic factors
Inherited factors also affect our health e.g. Cholesterol
People who exercise regularly are usually healthier than people who take little exercise.
B1.1.2 How our bodies defend themselves against infectious diseases
Microbes that cause infectious disease are called pathogens.
Bacteria and viruses may reproduce rapidly insidethe body and may produce toxins. Viruses damage the
cells in which they reproduce.
The body has different ways of protecting itself against pathogens e.g. the skin
White blood cells help to defend against pathogens by: ingesting pathogens, producing antibodies and
producing antitoxins
The immune system of the body produces specific antibodies to kill a particular pathogen. This leads to
immunity from that pathogen.
Semmelweiss and his links with handwashing and reducing disease
It is difficult to develop drugs that kill viruses without also damaging the body’s tissues.
Pathogens mutate, producing resistant strains.
Painkillers don’t get rid of pathogens
Roles of antibiotics in treatment, and not successful against viruses
Strains of bacteria, e.g. MRSA, have developed resistance as a result of natural selection due to overuse
Mutations of pathogens produce new strains.
Need to develop new treatments
How a vaccine works e.g. MMR
How to culture microbes properly in petri dishes to avoid contamination + keep safe (e.g. incubation) In
school and college laboratories, cultures should be incubated, at a maximum temperature of 25 °C
B1.2.1 The nervous system
Nervous system allows body response to environment
Receptors detect stimuli (changes in the environment) e.g. eyes
Info from receptors passes along cells (neurones) in nerves to the brain.
The brain coordinates the response.
Reflex actions
Role of receptors, sensory neurones, motor neurones, relay neurones, synapses and effectors in simple
reflex actions.
B1.2.2 Control in the human body
Internal conditions that are controlled include: water content, ion content, temp and blood sugar
Hormones released from glands to help control body e.g. sex hormones
Roles of FSH, LH and oestrogen in menstrual cycle
Roles of oestrogen and progesterone in the contraceptive pill and how oestrogen alone leads to side
effects so often combined or progesterone only
Role of LH and FSH in IVF
B1.2.3 Control in plants
Plants are sensitive to environment e.g. light and moisture
Plants produce hormones to coordinate and control growth. Auxin controls phototropism and gravitropism
(geotropism).
Unequal distribution of auxin leads to uneven growth on one side
Plant growth hormones are used in agriculture and horticulture as weed killers and as rooting hormones.
B1.3.1 Drugs
Why and how new drugs are developed to be effective and safe
The use of trials including double blind and use of placebos
Use of statins to reduce risk of heart disease
The problems with thalidomide and how it can be used today
Misuse of illegal drugs and its effects on the body and society
Links of cannabis with mental health
Addiction, stimulants and depressants
Legal vs. illegal drugs
Use of performance enhancing drugs
B1.4.1 Adaptations
Plants often compete with each other for light, space, water and nutrients
Animals often compete with each other for food, mates and territory
Organisms, including microorganisms have features (adaptations) that enable them to survive in the
conditions in which they normally live
Extremophiles may be tolerant to high levels of salt, high temperatures or high pressures
SRR 2011
B1 Biology Checklist Specification 2011
Animals and plants may be adapted for survival in the conditions where they normally live, eg deserts,
the Arctic
Animals and plants may be adapted to cope with specific features of their environment, eg thorns,
poisons and warning colours to deter predators
B1.4.2 Environmental change
Changes in the environment affect the distribution of living organisms
Animals and plants are subjected to environmental changes. Such changes may be caused by living or
non-living factors such as a change in a competitor, or in the average temperature or rainfall
Living organisms can be used as indicators of pollution: lichens + invertebrates
Environmental changes can be measured using non-living indicators such as oxygen levels, temperature
and rainfall
B1.5.1 Energy in biomass
Radiation from the Sun is the source of energy for most communities of living organisms (photosynthesis
in green plants and algae)
The biomass at each stage in a food chain is less than it was at the previous stage. The biomass at each
stage can be drawn to scale and shown as a pyramid of biomass
The amounts of material and energy contained in the biomass of organisms is reduced at each
successive stage in a food chain e.g. lost in respiration
B1.6.1 Decay processes
Living things remove materials from the environment for growth + other processes and returned through
death and decay
Materials decay because of digestion by microbes (most active when warm, moist and aerobic
conditions)
In a stable community the materials are constantly cycled
B1.6.2 The carbon cycle
The constant cycling of carbon is called the carbon cycle
Describe the processes which add carbon to the atmosphere and those that take the carbon away
B1.7.1 Why organisms are different
Genetic info is carried by genes, which are passed on in the sex cells (gametes) from which the offspring
develop
The nucleus of a cell contains chromosomes (made up of genes, made up of DNA)
Different genes control the development of different characteristics of an organism (allele = different
version of the same gene)
Variation can be genetic (combination of genes inherited) or environmental or both
B1.7.2 Reproduction
2 forms of reproduction: sexual and asexual
New plants can be produced quickly and cheaply by taking cuttings from older plants. These new plants
are genetically identical to the parent plant
Modern cloning techniques include: tissue culture, embryo transplants, adult cell cloning
In genetic engineering, genes from the chromosomes of humans and other organisms can be ‘cut out’
using enzymes and transferred to cells of other organisms
Genes can also be transferred to the cells of animals, plants or microorganisms at an early stage in their
development so that they develop with desired characteristics
Concerns about GM crops include the effect on populations of wild flowers and insects, and uncertainty
about the effects of eating GM crops on human health
B1.8.1 Evolution
Darwin’s theory of evolution by natural selection
The theory of evolution by natural selection was only gradually accepted because: it challenged
creationism, insufficient evidence at the time, mechanism of inheritance + variation not understood at the
time
Other theories, including that of Lamarck, are based mainly on the idea that changes that occur in an
organism during its lifetime can be inherited
Studying the similarities and differences between organisms allows us to classify living organisms into
animals, plants and microorganisms, and helps us to understand evolutionary and ecological
relationships
Where new forms of a gene result from mutation there may be relatively rapid change in a species if the
environment changes
SRR 2011