B9.1 Explaining Inheritance (Topic 1) Flashcards
What are gametes?
Cell that contains only half the normal number of chromosomes. It joins with another sex cell during fertilisation, to produce a fertilised egg cell which contains a full set of chromosomes.
What are sperm cells?
The male gamete in animals.
What are pollen grains?
The male gametes in plants.
What are egg cells?
Another term for ovum.
What is a dominant allele?
Version of a gene (allele) that will always have an effect (as opposed to a recessive allele, whose effect will not be seen if a dominant allele is present).
What is a recessive allele?
Version of a gene (allele) that will only have an effect if the other allele is also recessive.
What is a genetic cross diagram?
A diagram showing how the alleles in two parents may form different combinations in the offspring, when parents reproduce.
What is a genotype?
The alleles for a certain characteristic that are found in an organism.
What is a phenotype?
The characteristics that a certain set of alleles cause.
What is homozygous?
If both alleles for a characteristic are the same, the organism is homozygous for that characteristic.
What is heterozygous?
If both alleles for a characteristic are different, the organism is heterozygous for that characteristic.
What is a punnet square?
Diagram used to predict the different characteristics that will be present in the offspring of two organisms with known combinations of alleles. You can use the square to work out the probability (how likely it is) that offspring will inherit a certain future.
What is probability?
The likelihood of something happening, often shown as a percentage chance. For example, there is a 50% chance that it will rain tomorrow.
