Inheritance/Genetics Flashcards
What is an allele?
A version of a gene.
What does homozygous mean?
Both alleles are the same.
What is a genotype?
The alleles of the organism.
What does heterozygous mean?
Alleles are different in an individual.
What is a phenotype?
The physical expression of a gene.
What does dominant mean?
The allele expressed in the heterozygote.
What does recessive mean?
The allele only expressed when homozygous.
What is co-dominance?
When both alleles are expressed in the phenotype.
What term should you use when crossing over alleles for gametes?
FOIL
(firsts, outsides, insides, lasts)
What are the 2 types of variation?
Continuous and discontinuous.
What is natural selection?
Those best adapted will survive to reproduce in greater numbers than those less well adapted. They will pass on advantageous alleles to the next generation. Therefore the offspring will tend to inherit advantageous characteristics.
What increases chance of mutation?
-Ionising radiation like x-rays or gamma rays
-Chemicals called mutagens like chemicals in tobacco
Define mutation?
A change to the base sequence of DNA.
What phrase do you use in antibiotic resistance?
MAVARIPS
What is DNA like in eukaryotes?
Found within the nucleus as linear chromosomes.
What is DNA like in prokaryotes?
In the cytoplasm in the form of a circular chromosome and many small plasmids.
How are nucleotides joined together in both DNA and RNA?
By covalent bonds between the sugar of one nucleotide and the phosphate group of the next nucleotide.
Give 3 differences of DNA and RNA:
1) RNA is single stranded, DNA is double stranded
2) RNA has a sugar called ribose, while DNA has a sugar called deoxyribose
3) RNA has the base uracil while DNA has the base thymine.
What is mRNA?
-Messenger RNA
-Found in nucleus
-Made in transcription
-Carries the code for building a specific protein from the nucleus to the ribosomes
What is tRNA?
-Transfer RNA
-Found in cytoplasm
-Made in translation
-Picks up amino acids from cytoplasm and brings them into position on the surface of a ribosome where they can be joined together in a specific order to make a specific protein
What is a gene?
A length of DNA which codes for a protein.
What do alleles do?
Code for different forms of a protein.
What is a genome?
One copy of all an organism’s DNA.
What is polygenic inheritance?
When some characteristics are controlled by several genes which influence each other.
What is polygenic inheritance more likely to show?
Continuous variation.
