Edexcel B1 Revision Cards

Front 1

B1 Revision Cards

Back 1

If you can answer all of the questions on these cards then you know everything you need to know to ace your exam!

Front 2

1. What are the 7 levels of classification?

2. What are main characteristics of each of the 5 kingdoms?

3. Why are viruses classified as non-living?

Back 2

1. Kingdom, phylum, class, order, family, genus and species.
2. Animalia: multicellular, heterotrophic feeders, no cell walls, cells have a nucleus.
Plantae: multicellular, autotrophic feeders (make own food using photosynthesis), cell walls made of cellulose, cells have a nucleus.
Fungi: multicellular, sapropyhtic feeders (eat dead stuff), cell walls not made of cellulose, cells have a nucleus.
Protoctista: mostly unicellular, cells have a nucleus.
Prokaryotae: unicellular, cells don't have a nucleus.
3. Because they don't show any of the life processes - eg. growth or feeding.

Front 3

1. What are the main characteristics of the phylum chordata?
2. What are the main characteristics of the 5 vertebrate groups?
3. Why are many vertebrates difficult to classify?

Back 3

1. They have a supporting rod running the length of their body - eg. spine.
2. Fish: poikilotherms (cold-blooded); gills; external fertilisation; oviparous (lay eggs).
Amphibians: poikilotherms, gills (young) and lungs (adults); external fertilisation; oviparous.
Reptiles: poikilotherms, lungs, internal fertilisation, oviparous.
Birds: homeotherms (warm-blooded), lungs, internal fertilisation, oviparous.
Mammals: homeotherms, lungs, internal fertilisation, viviparous (give birth to live young).
3. Some vertebrates have characteristics from different groups - eg. axolotls are amphibians but the adults have gills.

Front 4

1. Define species.
2. What are the limitations of this definition?
HIGHER ONLY
3. Why is binomial classification important?
4. Describe 2 difficulties with classification.

Back 4

1. A group of organisms that can interbreed to produce fertile offspring.
2. Many species can interbreed to produce fertile hybrids and some species reproduce asexually.
3. It allows scientists from different countries to communicate about species clearly regardless of the common name of that species in their different countries and shows the inter-relationships between species more clearly.
4. Many ducks can interbreed to produce fertile hybrids; ring species: neighbouring populations can interbreed successfully but those at either end of the ring cannot.

Front 5

1. Explain the importance of binomial classification for conservation.
2. How does variation complicate classification?
3. Distinguish between continuous and discontinuous variation.

Back 5

1. Using this system it is easy to identify known species and spot new ones; you can see how organisms are related; and identify areas of greater or lesser biodiversity so know where to target conservation efforts.
2. Variation within a species can be great making it difficult to know if an organism is a new species or part of an existing one.
3. Continuous variation: a range of possible values with individuals being anywhere along that range - eg. height.
Discontinuous: a characteristic that has distinct groups, individuals can only be in one group - eg. blood group.

Front 6

1. How are polar bears adapted for their environment?
2. How are Pompeii worms adapted to live in hydrothermal vents?
3. How do you graph: a. continuous variation and b. discontinuous variation?
4. What does a normal distribution curve show?
5. What are the 2 factors that affect variation?

Back 6

1. White fur for camouflage; blubber and thick fur for insulation; large, rough feet to prevent slipping.
2. No eyes as its very dark; covered in a layer of bacteria to protect it from extreme heat; lives in a papery tube to protect it from predators.
3. Continuous: line graph. Discontinuous: bar graph
4. That most individuals fall within the middle part of the range of continuous variation values.
5. Genes and environment.

Front 7

1. What is evolution?
2. What is natural selection?
3. What is the evidence supporting natural selection?
HIGHER ONLY
4. How does speciation occur?

Back 7

1. Gradual change in the characteristics of a species over long periods of time.
2. Individuals within a species have different characteristics; if there is competition for resources then only some individuals can survive; those individuals that are better adapted are more likely to survive and reproduce, they will pass those adaptations onto their offspring so over time there will be more members of the species that have those characteristics.
3. The development of warfarin resistance in rats and genetic information on different species.
4. When populations become isolated geographically and over time adapt to their new surroundings.

Front 8

1. What is in the nucleus of cells?
2. What are genes?
3. What are alleles?
4. Define each of these terms:
Dominant; recessive; homozygous; heterozygous; phenotype; and genotype.
5. Make sure you can draw and interpret genetic cross diagrams and Punnett squares.

Back 8

1. Genetic material in the form of chromosomes.
2. Sections of DNA located on chromosomes that code for proteins.
3. Different versions of a gene - eg. you have a gene for eye colour but the allele for blue eyes.
4. Dominant: only need one copy of the allele to have the characteristic.
Recessive: need 2 copies of the allele to have the characteristic.
Homozygous: having 2 copies of the same allele.
Heterozygous: having 2 different alleles.
Phenotype: the characteristics that an organism has.
Genotype: the alleles that an organism has.

Front 9

1. Describe the cause and symptoms of cyctic fibrosis.
2. Describe the cause and symptoms of sickle cell disease.
3. What is a carrier?
4. Make sure you can interpret family pedigree charts.

Back 9

1. A genetic disorder caused by a recessive allele. Symptoms are the production of too much mucous which leads to breathing difficulties; lung infections; and problems digesting food.
2. A genetic disorder caused by a recessive allele. Symptoms are abnormal (sickle) shaped red blood cells that are less able to carry oxygen leading to tiredness and shortness of breath; sometimes red blood cells clump together causing painful joints and even death if they block blood vessels.
3. Someone who has one copy of a recessive allele.

Front 10

1. What is homeostasis?
2. Which factors need to be kept constant in the body?
3. How is temperature controlled?
4. What is osmoregulation?
5. What is negative feedback?

Back 10

1. Maintaining a stable environment within the body.
2. Temperature, water levels, blood glucose levels and pH.
3. Too hot: sweating, vasodilation (veins near surface of skin become wider to allow heat to be lost from blood), hairs lie flat.
Too cold: shivering, vasoconstriction (veins near skin surface get thinner to prevent heat loss from blood), hairs stand up.
4. The control of water levels in body - eg. through production of more dilute/concentrated urine.
5. A change is detected and mechanisms in the body work to reverse it.