Reproduction Flashcards
What is the process involving the fusion of the nuclei of two gametes to form a zygote?
Sexual reproduction
It involves the production of genetically different offspring.
How many parent organisms are required for sexual reproduction?
Two
What type of cell division produces gametes in sexual reproduction?
Meiosis
What type of cell division occurs after fertilisation in sexual reproduction?
Mitosis
What is the genetic relationship between offspring produced by sexual reproduction and their parents?
Genetically different
What percentage of DNA do offspring share with each parent in sexual reproduction?
50%
Is sexual reproduction a fast or slow process?
Relatively slow
What advantage does variation introduced by sexual reproduction provide to populations?
Survival advantage
What is asexual reproduction?
The process resulting in genetically identical offspring from one parent
Does asexual reproduction involve gametes or fertilisation?
No
How many parent organisms are required for asexual reproduction?
One
What is the genetic relationship between offspring produced by asexual reproduction?
Genetically identical to the parent and to each other
What is a major benefit of asexual reproduction over sexual reproduction?
Occurs much more quickly and efficiently
What is a disadvantage of asexual reproduction?
Lack of genetic variation
Which type of organisms commonly reproduce via asexual reproduction?
Many plants
What is binary fission?
A type of asexual reproduction in bacteria
What is the number of parent organisms in asexual reproduction?
One
What type of cell division is required to produce offspring in asexual reproduction?
Mitosis
What type of cell division is required for sexual reproduction?
Meiosis (to produce gametes)
How many sources of genetic variation are there in sexual reproduction?
Three
What are the three sources of genetic variation in sexual reproduction?
- Contribution of 50% DNA from each parent
- Production of gametes by meiosis
- Random assortment of chromosomes during meiosis
How many offspring are usually produced in asexual reproduction?
Relatively large numbers
How long does it usually take to produce offspring in asexual reproduction?
Usually relatively fast
What are gametes?
Sex cells produced by meiosis
What are the human gametes called?
Sperm and ovum
What do gametes contain in terms of chromosomes?
Half the number of chromosomes compared to normal body cells
What adaptation do sperm cells have?
A tail to propel them towards the egg
What adaptation do egg cells have?
Energy stores within the cytoplasm
What is fertilisation?
The fusion of a male and female gamete to produce a zygote
What does the zygote divide into after fertilisation?
Embryo
What occurs during the development of the zygote?
Cells start to become specialised
Where does fertilisation occur in humans?
In the oviduct
What is the chromosome count in a human zygote?
46 chromosomes (23 pairs)
How is fertilisation achieved in plants?
When a pollen tube delivers the male nucleus into the ovary
