B6 - Inheritance, varation and evolution Flashcards
What is a nucleotide?
Sugar + a phosphate + a base
What is tissue culture?
A method of cloning using small groups of cells from part of a plant to grow identical new plants
What are cuttings?
A simple method used by gardeners to produce many identical new plants from a parent plant
What are embryo transplants?
A method of cloning which involves splitting apart cells from a developing animal embryo before they become specialised, then transplanting the identical embryos into host mothers
What is adult cell cloning?
A nucleus is placed into empty egg cell and is inserted into the womb of an adult female
What is speciation?
The formation of a new species through natural selection from an isolated population
What is sexual reproduction?
Reproduction which involves the fusion of male and female gametes
What is asexual reproduction?
Reproduction that involves only one parent with no fusion of gametes
What is meiosis?
Cell division which halves the number of chromosomes, forming gametes
What is DNA?
A double-helix of polymers that contains the recipe for life, contained in chromosomes
What is a gene?
A small section of DNA on a chromosome which codes for a protein
What is a genome?
The entire set of genetic material of an organism
What is a mutation?
A change in the DNA
What is a gamete?
Sex cells, such as egg and sperm cells
What is an allele?
The different versions of a gene
What is a dominant gene?
A gene that is expressed in the phenotype when at least one allele is present
What is a recessive gene?
A gene that is expressed in the phenotype if both alleles are present
What is true of the alleles in a homozygous pair?
The alleles present in each gene are the same
What is true of the alleles in a heterozygous pair?
The alleles present in each gene are different
What is a genotype?
The alleles that are present
What is a phenotype
The physical characteristics/features that are present as a result of a gene
What is cystic fibrosis
A disorder of cell membranes where mucus is thick and sticky
What is polydactyly
An inherited disorder where the individual has extra digits (fingers or toes)
What is variation?
The differences in the characteristics of individuals in a population
What is evolution?
A change in the inherited characteristics of a population over time through the process of natural selection
What is natural selection
A process which gives rise to phenotypes best suited to their environment
What is selective breeding
The process by which humans breed plants and animals for particular genetic characteristics
What is genetic engineering
A process which involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic
What are fossils?
The preserved remains of organisms from millions of years ago, which are found in rocks
What is extinction
When there are no remaining individuals of a species still alive
What is the binomial system?
Naming organisms by their genus and species
