Asexual reproduction has genetically identical offspring because
one parent, no fusion of gametes
Sexual reproduction has variation in offspring because
two parents, fusion of gametes and mix of genetic info
Meiosis step by step
All chromosomes are copied
Cell divides in two
both of these cells divide into two
Meiosis halves/doubles number of chromosomes
halved the number of chromosomes
dna consists of x strands
two strands
double helix
two strands wrap around eacother
gene
small section of DNA on a chromosome
benefits of studying human genome
search for genes linked to disease
understand inherited disorders
trace human migration patterns from the past , helps with ancestry
alleles
different versions of a gene
genotypes
The alleles that an organism has for a particular characteristic
phenotypes
characteristics caused by the alleles
cystic fibrosis reccessive/dominant AND what it is
recessive allele , defective cell membrane
polydactyly reccessive/dominant AND what it is
dominant allele, extra fingers or toes
3 problems with embryo screening
expensive
large number of embryos created, small are used. so lots are destoreyd
future we can screen them to produce desired offspring. unethical