genetics Flashcards
(33 cards)
What is an allele?
A version of a gene.
What are amino acids?
Small molecules from which proteins are assembled.
What is asexual reproduction?
A form of reproduction involving a single parent that creates genetically identical offspring.
What is a base triplet?
A sequence of three bases in a gene that code for a particular amino acid.
Also known as a codon.
What is a blood group?
Classification of blood type as A, B or O based on surface antigens on red blood cells and the presence of certain antibodies in the plasma.
What is a chromosome?
A long, coiled molecule of DNA that carries genetic information in the form of genes.
What is complementary base pairing?
Describes how weak hydrogen bonds form between complementary base pairs. A pairs with T and C pairs with G.
What is a diploid cell?
A cell that contains two copies of each chromosome (i.e. a full set of chromosomes).
What is DNA?
A double-stranded polymer, wound to form a double helix, that carries the genetic code.
What does dominant mean in genetics?
Describes an allele that is always expressed. Represented by a capital letter.
What is environmental variation?
Differences in phenotype acquired during the lifespan of an organism due to environmental factors such as diet, lifestyle, climate, exposure to light, etc.
What is fertilisation?
The fusion of the nucleus of male and female gametes. Restores the full chromosome number.
What are gametes?
Sex cells (sperm and egg cells) with half the usual number of chromosomes.
What is a gene?
stretch of DNA, codes for characteristics
What is genetic variation?
Differences in the genotypes of organisms of the same species due to the presence of different alleles, arising through mutations and sexual reproduction. It creates variation in phenotypes.
What is a genome?
The complete genetic material of an organism.
What is a genotype?
An organism’s genetic composition. Describes all alleles.
What is a haploid cell?
A cell that contains a single copy of each chromosome (i.e. half the number of chromosomes).
What does heterozygous mean?
When someone has two different alleles of a gene, e.g. Ff.
What does homozygous mean?
When someone has two identical alleles of a gene, e.g. ff.
What is the Human Genome Project?
An international research project involving thousands of scientists which successfully mapped the entire human genome.
What is meiosis?
A form of cell division that produces four genetically different daughter cells (gametes) with a haploid number of chromosomes. It involves two divisions.
What is a mutation?
A random change in the base sequence of DNA which may result in genetic variants.
name the bases in DNA structure and structure of DNA
AT , CG, double helix structure
