Inheritance , Variation And Evolution Flashcards
What is meiosis and mitosis (compare)
Mitosis:
Asexual reproduction
Two genetically identical daughter cells created
Involves no fusion of gametes
Meiosis:
Sexual reproduction
Mixing of genetic information leading to a variety of offpseing
Involve fusion of gametes
How does meiosis halve the chromsomes and restore it back during fertilisation
Cells in reproductive oragsb divide by meiosis too form gametes:
Copies of genetic material are made when cells divide twice to form four gametes which are all different from each other
Gametes join at fertilisation to restore the normal number of chromsomes. The new cell divides by mitosis and number of cells increase. As the embryo develops cells differentiate
Describe the structure of DNA
Genetic mateiral inside a nucleus of a cell is composed of DNA (polymer made up of two strands-double helix)
Define genome and gene
Genome of an organism is the entire genetic msterial of that organism. The whole human genome has now been studied and be important for medicine in the future
Gene is a small section of DNA on a chromsome which codes for a particular sequence of amino acids for a specific protein
Why is understanding the genome important
Search for genes linked to differnt types of diseases
Understanding and treatemenf of inherited disorders
Use in tracing human migration patterns from the past
What is gamete
A gamete is a reproductive cell of an animal or plant.
What is chromosome
Chromosomes are thin strands of DNA
What is a gene
gene is a section of DNA which controls part of a cell’s chemistry - particularly protein production.
What is an allele
Alleles. are different versions of the same gene.
What is a dominant and recessive allele
What is homozygous and heterozygous
What si genotype and phenotype
Ethicsal , social and economic issues of embryo screening
What are the sex chromosomes in males and females
Describe how genomes and its interaction with the environemnt influence the phenotype of an organism
