Flashcards
variaion
Flashcards do conjunto (23)
- 1what are the male and female gametes called and where are the produced ?male = sperm ( testes)
female = egg (ovaries) - 2how are identical twins formed ?a fertilised egg spits in 2
- 3how are non - identical twins formed?2 separate eggs are fertilised by 2 separate sperm
- 4Give 2 examples of genetic variationattached or unattached earlobes
eye colour - 5give an examples of environmental variationscars
- 6What is the hereditary material and where is it found ?DNA , found in the nucleus of the cell
- 7What are chromosomes ?a chromosomes is a bundle of DNA
- 8How many chromosomes are found in a human body cell46 or 23 pairs
- 9What is a gene?a gene is a section of DNA that codes for a particular characteristic
- 10How are chromosomes arranged ?they are arranged in homologous pairs
- 11What is an allele ?An allele is an alternate version of a gene, eg you inherit 2 alleles for eye colour one from each parent
- 12Which allele is always expressed and which do you need 2 copies of to be expressed ?the dominant allele is always expressed but you need 2 copies of the recessive allele for it to be expressed
- 13What sex chromosomes are carried by the male and femalemales carry Xy chromosomes
females carry XX chromosomes - 14who determines the sex of the babythe male
- 15Are most genetic disorders found on recessive alleles or dominant onesrecessive
- 16If B is the allele for Brown eyes and b is the allele for blue eyes , which combination of alleles would be needed for a person to have blue eyesbb
- 17what is a persons genotype?the genes they carry
- 18what is a persons phenotype?the characteristics that a person shows
- 19what is cystic fibrosis and is it recessive or dominant?recessive - caused by a defective gene that means the person produces too much mucus that can lead to chest infections
- 20What is Huntingtons and is it dominant or recessive ?it is a dominant condition that causes nerve damage
- 21what is sickel cell anaemia and is it dominant or recessive?it is a recessive condition that causes red blood cells to be the wrong shape -they then block capillaries stopping oxygen getting to cells
- 22Draw a genetic diagram to the genetic make up of the offpring of a male parent with the genotype Cc and female with genotype Cc
- 23Draw a genetic diagram to show that the percentage chance of 2 parents producing male or female offspring is 50%
