B13 - Reproduction Flashcards
What are alleles?
Different forms of the same gene, sometimes referred to as variants
What is asexual reproduction?
involves only 1 individual and the offspring is identical to the parent. There is no fusion of gametes or mixing of genetic information
What are bases (DNA)?
Nitrogenous compounds that make up part of the structure of DNA and RNA. They are represented by the letters A, T, C, and G
What are carriers?
Individuals who are heterozygous for a recessive allele linked to a genetic disorder. Carriers have one healthy allele so are not affected themselves, but can pass on the affected allele to their offspring
What is cystic fibrosis?
An inherited disorder that affects lungs, digestive, and reproductive system and is inherited through a recessive allele
What is a dominant allele?
The phenotype will be apparent in the offspring even if only one of the alleles is inherited
What is genetic engineering?
The process by which scientists can manipulate and change the genotype of an organism
What is a genotype?
The genetic makeup of an individual for a particular characteristic, for example hair or eye colour
What is a heterozygote?
Individual with different alleles for a characteristic
What is a homozygote?
Individual with different alleles for a characteristic
What is meiosis?
2 stage process of cell division that reduces the chromosome number of daughter cells. It is involved in making gametes for sexual reproduction
What is a mutation?
A change in the genetic material of an organism
What is natural selection?
The process by which evolution takes place. Organisms produce more offspring than the environment can support. Only those that are most suited to their environment will survive to breed and pass on their useful characteristics to their offspring
What is a nucleotide?
A molecule made up of a sugar, a phosphate group, and one of 4 different bases. They are key units in the structure of DNA and RNA
What is a phenotype?
The physical appearance of an individual for a particular characteristic
What is polydactyly?
A dominant inherited disorder that results in babies born with extra fingers and/or toes
What is a Punnet square diagram?
A way of modelling a genetic cross and predicting the outcome using probability
What is a recessive allele?
A phenotype that will only show up in the offspring if both of the alleles coding for that characteristic are inherited
What are sex chromosones?
Carry the information that determines the sex of an individual
What is sexual reproduction?
Involves the fusion of male and female gametes producing genetic variation in the offspring
What is reproduction?
The process by which genetic information is passed on from parents to their offspring
What are advantages of a asexual reproduction?
- Partner not required
- Genetically identical offspring (known as clones) meaning there is no genetic variation and therefore desirable characteristic are passed on. This also is an advantage in favourable conditions.
- It is faster and more rapid than sexual reproduction
What are the disadvantages of asexual reproduction?
- Genetically identical offspring (known as clones) meaning there is no genetic variation and therefore undesirable characteristics may be passed on
- Large groups may be susceptible to the same disease, meaning none of the population are immune, causing the entire population to fall ill to the disease. If one organism cannot survive, none can.
What are gametes?
an organism’s reproductive cells, they contain 1 set of chromosomes so can carry only 1 of the 2 alleles that the parent have in their own cells