Flashcards
7.1 Genetic variation
Flashcards do conjunto (31)
- 1Why might an individuals have differences in characteristics of the same kind?Differences in:
The genes they have inherited (genetic causes)
The conditions in which they have developed (environmental causes)
A combination of the above - 2What carries the information that results in plants and animals having similar characteristics to their parents?Genes
- 3How are genes passed on?In the sex cells (gametes) from which offspring develop
- 4Where are chromosomes found?In the nucleus of a cell
- 5What do chromosomes carry?Genes that control the characteristics of the body
- 6How are chromosomes found?In pairs
- 7How many pairs of chromosomes are there in a cell?23 pairs of chromosomes
- 8How many paris of chromosomes in human body cells carry the genes that determine sex?One
- 9Which are the sex chromosomes in females?XX
- 10What are the sex chromosomes in males?XY
- 11What do different genes control?The development of different characteristics of an organism
- 12What are alleles?Different forms of the same gene
- 13What is homozygous?If both chromosomes in a pair contain the same allele of a gene
- 14What is heterozygous?If the chromosomes in a pari contain different alleles of a gene
- 15What is a dominant allele?An allele that controls the development of a characteristic when it is present on only one of the chromosomes
- 16What is a recessive allele?An allele that controls the development of a characteristic only if the dominant allele is not present
- 17Which principles did Mendel use in mono hybrid inheritance in peas?He was trying to explain why some characteristics (such as white flower colour) disappear in one generation but reappear in the next
Interpreted his results in terms of separate 'inherited factors', which we now call genes
Mendel's work preceded the work by other scientists which linked Mendel's 'inherited factors' with chromosomes - 18What is phenotype?The physical appearance resulting from inherited information
e.g. someone with blue eyes has the phenotype blue eyes - 19What is genotype?The genotype is the DNA sequence that determines the characteristic (phenotype)
- 20What are the two forms of reproduction?Sexual reproduction
Asexual reproduction - 21What is sexual reproduction?The joining (fusion) if male and female gametes
The mixture of genetic information from two parents leads to variety in the offspring - 22What is asexual reproduction?No fusion of gametes and only one individual is needed as the parent
There is no mixing of genetic information and so no genetic variation in the offspring
These genetically identical individuals are known as clones - 23What are chromosomes made up of?DNA
- 24What does DNA stand for?Deoxyribonucleic acid
- 25What does DNA contain?The coded information that determines inherited characteristics
- 26What is a gene?A small section of DNA
- 27What does each gene code for?a particular combination of amino acids, to make a specific protein
- 28What are the strands of DNA called?Double Helix
- 29What do double helix's contain?Four different compounds, called bases
- 30What does a sequence of three bases code for?A particular amino acid
- 31What does the order of bases control?The order in which amino acids are assembled to produce a particular protein
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- GCSE Biology (7 Variation and inheritance) FlashCards sobre 7.1 Genetic variation, criado por Anisha Rai em 25-04-2016.
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- Anisha Rai
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