Genetics and Genetic engineering Flashcards
what is the definition of identity?
genetics is the study of heredity and variation in organisms.
Who was Gregor Mendel and what was he responsible for?
Mendel is now considered to be the father of genetics as he was responsible for some of the most important breakthroughs in the topic.
He investigated the transfer of genetic characteristics from one generation to the next one
his achievements were recognised years after his death
He was the one that realised how sexual reproduction combines “something” from each parent to produce offsprings which are unique yet the same.
What is a gene?
Genes are found on the chromatids and each DNA molecule is therefore made out of a series of genes.
What is the difference between a somatic cell and a gamete?
A gamete is a sex cell while a somatic cell is any cell that makes up the organism
Are all genes constantly active?
Only the genes which are needed to perform a specific function are activated while the others remain dormant. Some genes are however active in different types of cells as they perform different types of functions.
What are alleles?
alleles are genes which are responsible for controlling different versions of a trait. They are found in the same area on the homologous chromosomes ( maternal and paternal)
They are represented by a big letter if dominant ( i.e B) or small letter if recessive ( i.e b)
Are body cells diploid and gametes haploid?
Yes they are. body cells and gametes both have one set of homologous chromosomes but body cells have two alleles while gametes only have one pair of alleles
What is the difference between genotype and phenotype?
A genotype is made up of all the genes which are present in an organism (Bb bb BB)
A phenotype if the physical characteristic/appearance of an organism (tallness, hair colour etc…)
What is the difference between heterozygous and homozygous?
an organism is homozygous when the pair of alleles are the same (BB bb) while an organism is heterozygous when the pair of alleles are different (Bb)
What is the difference between a dominant and recessive allele?
A dominant allele is the trait which is transmitted to the offspring while the recessive allele is the one who is dominated by the dominant allele and will therefore not be seen in the offspring
what is continuos variation?
the graduations of a characteristic in a phenotype ( heigh in a human , metabolic rate, etc…)
what is a genome?
A genome is the complete set of genes required to create an organism
Why did Mendel choose to examine pea plants?
they are small in size and can therefore be easily cultivated
they reproduce at a fast speed
they can self pollinate
they come in many varieties
What was Mendel trying to establish through his studies?
He was trying to establish what happens to the different traits when they are combined together to form a hybrid
