1
Q
Explain the term gamete.
A
- It is haploid, containing only one set of dissimilar chromosomes
2
Q
Explain the term chromosome.
A
- A chromosome is a thread-like structure made of DNA and proteins found in the nucleus of cells
3
Q
Explain the term gene.
A
- A segment of DNA that codes for a particular type of protein
4
Q
Explain the term allele
A
- Different versions of the same gene
5
Q
Explain the term dominant.
A
- Always expressed even if only one copy is present
6
Q
Explain the term recessive.
A
- Only expressed if two copies are present (therefore no dominant allele present)
7
Q
Expand the term homozygous.
A
- If the two alleles present are the same
8
Q
Explain the term heterozygous.
A
- If the two alleles present are different
9
Q
Explain the term genotype.
A
- The chemical composition of an organism’s DNA that gives rise to its observable traits (phenotype).
10
Q
What characteristics are controlled by a single gene?
A
- Fur colour in mice
- Red-green colour blindness in human
- Each gene may have different forms called alleles
11
Q
Explain the term phenotype.
A
- The observable physical properties of an organism; these include the organism’s appearance, development.
12
Q
Why do the allele or genotype present operate at a molecular level?
A
- To develop characteristics that can be expressed as a phenotype
13
Q
When is a dominant allele expressed?
A
- Always expressed even if only one copy is present
14
Q
When is a recessive allele expressed?
A
- Only expressed if two copies are present (therefore no dominant allele present)
15
Q
When is an organism homozygous?
A
- If the two alleles present are the same
16
Q
When is an organism heterozygous?
A
- If the two alleles present are different
17
Q
What are most characteristics a result of?
A
- Multiple genes interacting rather than a single gene
GCSE Biology
flashcards
Decks in class (124)
# Cards
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4.1 Cell biology0
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4.1.1 Cell structure0
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4.1.1.1 Eukaryotes and prokaryotes1
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4.1.1.2 Animal and plant cells0
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4.1.1.3 Cell specialisation0
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4.1.1.4 Cell differentiation0
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4.1.1.5 Microscopy0
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4..1.1.6 Culturing microorganisms0
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4.1.2 Cell division0
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4.1.2.1 Chromosomes0
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4.1.2.2 Mitosis and the cell cycle0
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4.1.2.3 Stem cells0
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4.1.3 Transport in cells0
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4.1.3.1 Diffusion0
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4.1.3.2 Osmosis0
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4.1.3.3 Active transport0
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4.2 Organisation0
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4.2.1 Principles of organisation0
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4.2.2 Animal tissues, organs and organ systems0
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4.2.2.1 The human digestive system0
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4.2.2.2 The heart and blood vessels0
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4.2.2.3 Blood0
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4.2.2.4 Coronary heart disease: a non-commutable disease0
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4.2.2.5 Health issues0
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4.2.2.6 The effect of life cycle on some non-communicable diseases0
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4.2.2.7 Cancer0
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4.2.3 Plant tissues, organs and systems0
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4.2.3.1 Plant tissues0
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4.2.3.2 Plant organ system0
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4.3 Infection and response0
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4.3.1 Communicable diseases0
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4.3.1.1 Communicable (infectious) diseases0
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4.3.1.2 Viral diseases0
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4.3.1.3 Bacterial diseases0
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4.3.1.4 Fungal diseases0
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4.3.1.5 Protist diseases0
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4.3.1.6 Human defence systems0
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4.3.1.7 Vaccination0
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4.3.1.8 Antibiotics and painkillers0
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4.3.1.9 Discovery and development of drugs0
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4.3.2 Monoclonal antibodies0
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4.3.2.2 Uses of monoclonal antibodies0
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4.3.3 Plant disease0
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4.3.3.1 Detection and identification of plant diseases0
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4.3.3.2 Plant defence responses0
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4.4 Bioenergetics0
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4.4.1 Photosynthesis0
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4.4.1.1 Photosynthesis reaction0
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4.4.1.2 Rate of photosynthesis0
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4.4.1.3 Uses of glucose from photosynthesis0
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4.4.2 Respiration0
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4.4.2.1 Aerobic and anaerobic respiration0
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4.4.2.2 Response to exercise0
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4.4.2.3 Metabolism0
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4.5 Homeostasis and response0
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4.5.1 Homeostasis0
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4.5.2 The human nervous system0
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4.5.2.1 Structure and function0
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4.5.2.2 The brain0
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4.5.2.3 The eye0
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4.5.2.4 Control of body temperature0
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4.5.3 Hormonal coordination in humans0
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4.5.3.1 Human endocrine system0
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4.5.3.2 Control of blood glucose concentration0
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4.5.3.3 Maintaining water and nitrogen balance in the body0
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4.5.3.4 Hormones in human reproduction0
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4.5.3.5 Contraception0
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4.5.3.6 The use of hormones to treat fertility0
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4.5.3.7 Negative feedback0
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4.5.4 Plant hormones0
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4.5.4.1 Control and coordination0
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4.5.4.2 Use of plant hormones0
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4.6 Inheritance variation and evolution0
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4.6.1 Reproduction0
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4.6.1.1 Sexual and asexual reproduction7
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4.6.1.2 Meiosis8
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4.6.1.3 Advantages and disadvantages of sexual and asexual reproduction7
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4.6.1.4 DNA and the genome8
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4.6.1.5 DNA structure22
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4.6.1.6 Genetic inheritance17
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4.6.1.7 Inherited disorders4
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4.6.1.8 Sex determination4
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4.6.2 Variation and evolution0
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4.6.2.1 Variation3
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4.6.2.2 Evolution4
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4.6.2.3 Selective breeding5
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4.6.2.4 Genetic engineering8
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4.6.2.5 Cloning4
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4.6.3 The development of understanding of genetics and evolution0
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4.6.3.1 Theory of evolution5
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4.6.3.2 Speciation6
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4.6.3.3 The understanding of genetics7
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4.6.3.4 Evidence for evolution4
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4.6.3.5 Fossils4
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4.6.3.6 Extinction2
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4.6.3.7 Resistant bacteria5
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4.6.4 Classification of living organisms6
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4.7 Ecology0
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4.7.1 Adaptation, interdependence and competition s0
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4.7.1.1 Communities0
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4.7.1.2 Abiotic factors0
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4.7.1.3 Biotic factors0
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4.7.1.4 Adaptations0
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4.7.2 Organisation of an ecosystem0
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4.7.2.1 Levels of organisation0
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4.7.2.2 How materials are cycled0
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4.7.2.3 Decomposition0
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4.7.2.4 Impact of environmental change0
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4.7.3 Biodiversity and the effect of human interaction on ecosystems0
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4.7.3.1 Biodiversity0
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4.7.3.2 Waste management0
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4.7.3.3 Land use0
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4.7.3.4 Deforestation0
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4.7.3.5 Global warming0
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4.7.3.6 Maintaining biodiversity0
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4.7.4 Trophic levels in an ecosystem0
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4.7.4.2 Pyramids of biomass0
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4.7.4.3 Transfer of biomass0
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4.7.5 Food production0
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4.7.5.1 Factors affecting food security0
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4.7.5.2 Farming techniques0
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4.7.5.3 Sustainable fisheries0
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4.7.5.4 Role of biotechnology0
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4.8 Key ideas0
