kjml,; Flashcards
(25 cards)
What is reproduction?
How living things create new individuals
Essential for the survival of every species.
How many parents are needed for asexual reproduction?
One parent
How many parents are needed for sexual reproduction?
Two parents
What are the two main types of reproduction?
- Sexual reproduction
- Asexual reproduction
Define asexual reproduction.
A type of reproduction where one parent produces genetically identical offspring
What is a key characteristic of asexual reproduction?
No gametes involved
What is a major disadvantage of asexual reproduction?
No genetic variation
Give an example of asexual reproduction.
- Bacteria dividing (binary fission)
- Potato tubers
- Strawberry runners
- Starfish regenerating
Define sexual reproduction.
A type of reproduction that requires two parents and involves the fusion of gametes
What is a key benefit of sexual reproduction?
Increases genetic variation
Give examples of organisms that reproduce sexually.
- Humans
- Animals
- Flowering plants
What is meiosis?
Reproductive cell division in which each daughter cell is haploid and not genetically identical to the parent cell
What type of cells does meiosis produce in humans?
Sperm and egg cells
What does haploid mean?
Contains half the number of chromosomes needed
What does diploid mean?
Contains complete set of chromosomes needed
What significant event occurs during Prophase I of meiosis?
Crossing over
Why are the daughter cells produced by meiosis haploid?
To restore the original number of chromosomes when sex cells combine
How does meiosis ensure genetic variation?
Due to crossing over and independent assortment
What are gametes?
Sex cells – egg and sperm cells
What is spermatogenesis?
Production of sperm cells (male gametes)
What is oogenesis?
Production of egg cells (female gametes)
What happens to polar bodies during oogenesis?
They die
Why is meiosis referred to as ‘reduction division’?
Because it reduces the chromosome number by half
What are the two features of meiosis that give rise to genetic variation?
- Crossing over
- Independent assortment
