Reproduction Flashcards
What is sexual reproduction
The process involving the fusion of the nuclei of two gametes to form a zygote (fertilised egg cell) and the production of offspring that are genetically different from each other
What are gametes
A gamete is a sex cell
How are gamates different from normal cells
Gametes differ from normal cells as they contain half the number of chromosomes found in other body cells - we say they have a haploid nucleus
This is because they only contain one copy of each chromosome, rather than the two copies found in other body cells
In human beings, a normal body cell contains 46 chromosomes but each gamete contains 23 chromosomes
What is it called when a male and female gamete fuse
When the male and female gametes fuse, they become a zygote (fertilised egg cell)
What are the advantages of sexual reproduction
Increase genetic variation
Species can adapt to new environment due to variation giving them a survival advantage
Diseases are less likely to affect population
What are the disadvantages of sexual reproduction
Take time and energy to find mates
difficult for isolated members of the species to reproduce
What is A sexual reproduction
The process resulting in genetically identical offspring being produced from one parent
What are the advantages of Asexual reproduction
Population can be increased rapidly when conditions are right
can exploit suitable environments quickly
More time and energy efficient
much quicker
What are the disadvantages of Asexual reproduction
population vulnerable to changes in conditions and may only be suited to one habitat
Disease likely to affect whole population as no genetic variation
What are the key differences between sexual and asexual reproduction
The number of parent organisms
How offspring are produced (the type of cell division required)
The level of genetic similarity between offspring
The possible sources of genetic variation in offspring
The number of offspring produced
The time taken to produce offspring
What is fertilisation
Fertilisation is defined as the fusion of gamete nuclei, and as each gamete comes from a different parent, there is variation in the offspring
