B13 reproduction Flashcards
What are amino acids made from
Gene codes which are made from nucleotide
What is meiosis
Cell division in reproductive organs resulting in gametes
What’s are gametes
Sex cells in animals egg and sperm in plants pollen and egg
What’s is a clone
A genetically identical organisms
What’s a phenotype
The physical characteristics that a organism has due to the genotypes genetic coating
Genotype
The two alleles an organism has for a specific characteristic
What’s an Allele
A version of a gene some may have an allele for blue eyes and other may have one for brown eyes
What are dominant alleles
A allele which is always expressed in phenotype (strong gene)
What’s variation
The differences in organisms
What’s DNA
A polymer made up of two strands which makes a double helix, these strands contain nucleotides
What are chromosomes
Long strands of DNA wrapped around proteins which contain genes there are 23 pairs of them in humans
What’s a gene
A small section of DNA on a chromosome each gene codes for a protein
What is genome
All the genetic material in a organism
What’s a recessive allele
It is only expressed in the phenotype if there is no dominant allele (weaker gene)
What’s homozygous
When the alleles in a genotype are the same
What’s heterozygous
When the alleles in a genotype are different
What’s polydactyl
An inherited condition where you have an extra finger or toe which is controlled by a dominant allele
What is cystic fibrosis
An inherited condition where thick sticky mucus is produced in the lungs and digestive system which is controlled by a recessive allele
How does sexual reproduction work
It’s the fusion of male and female gametes where genetic information is mixed causing variation in offspring
How does Asexual reproduction work
Involves only 1 parent and no fusion of gametes which means genetic information can’t be mixed which leads to genetically identical offspring (clones)
Describe the 1st stage of sexual reproduction
Starts with meiosis causing cells in the reproductive organs to divide forming gametes
Describe the 2nd stage of sexual reproduction
Once the cells divide they divide again forming 4 gametes each with a single set of chromosomes
Describe the 3rd stage of sexual reproduction
Each gamete is genetically different as they have taken different parts of DNA
Describe the 4th stage of sexual reproduction
When the gametes join at fertilisation the cell returns to the normal amount of chromosomes
Describe the 5th stage of sexual reproduction
The new cell with a combination of DNA divides by mitosis forming an embryo. Cells in the embryo differentiate to form specialised cells as it develops more.
What do we use to predict the probability of characteristic
By doing a genetic cross using a punnet square
What’s do the pairs of chromosomes determine
The first 22 pairs determine the characteristic and the last pair the sex
What’s are the chromosomes of a female compared to a male
Females have the same last chromosomes (XX) where as males are different (XY)
Advantages of genetic screening
Aborting a pregnancy to save the child from suffering from the genetic disease
Disadvantage of genetic screening
We shouldn’t have the right to end a life of an unborn child
