Reproduction Flashcards
What is sexual reproduction?
Sexual reproduction involves the fusion of gametes (sperm and egg) from two parents, resulting in offspring with genetic contributions from both.
What is asexual reproduction?
Asexual reproduction is a process where a single organism produces offspring that are genetically identical to itself, without the involvement of gametes.
What are the main advantages of asexual reproduction?
Asexual reproduction allows for rapid population growth and the production of genetically identical offspring that are well-adapted to stable environments.
How does sexual reproduction contribute to genetic variation?
Sexual reproduction creates offspring with new gene combinations through the mixing of parental genes, leading to increased genetic diversity.
Why is genetic variation important for adaptation?
Genetic variation provides a population with a broader range of traits, enhancing the ability to adapt to changing environments and survive challenges such as diseases or climate shifts.
What is one common method of asexual reproduction?
Common methods of asexual reproduction include binary fission (in bacteria), budding (in yeast), and vegetative propagation (in plants).
What is one example of an organism that reproduces sexually?
Many animals, including humans, reproduce sexually by combining genetic material from two parents.
How does the rate of reproduction differ between sexual and asexual methods?
Asexual reproduction typically allows for faster population growth since it does not require finding a mate, while sexual reproduction may result in slower growth due to mating processes.
What role does environmental stability play in the choice between sexual and asexual reproduction?
In stable environments, asexual reproduction may be favored for its efficiency, while sexual reproduction may be advantageous in changing environments to enhance adaptability.
Can some organisms switch between sexual and asexual reproduction?
Yes, some organisms, such as certain plants and fungi, can switch between sexual and asexual reproduction depending on environmental conditions and resource availability.
What is meiosis?
Meiosis is a type of cell division that reduces the chromosome number by half, producing four genetically diverse gametes from a single diploid cell.
How does meiosis contribute to genetic variation?
Meiosis breaks up parental combinations of alleles through processes such as independent assortment and crossing over, resulting in gametes with new genetic combinations.
What is the significance of crossing over during meiosis?
Crossing over allows for the exchange of genetic material between homologous chromosomes, increasing genetic diversity among offspring.
What is fertilization?
Fertilization, also known as the fusion of gametes, is the process where male and female gametes combine to form a diploid zygote.
How does fertilization contribute to genetic variation?
Fertilization combines alleles from two parents, producing offspring with unique genetic combinations distinct from either parent.
What are gametes?
Gametes are specialized reproductive cells (sperm and eggs) that carry half the genetic information necessary for sexual reproduction.
What is the outcome of meiosis in terms of chromosome number?
Meiosis reduces the chromosome number from diploid (2n) to haploid (n), ensuring that offspring have the correct chromosome number when gametes fuse during fertilization.
Why is it important for meiosis to occur before fertilization?
Meiosis ensures that gametes contain only one set of chromosomes, allowing for the restoration of the diploid chromosome number upon fertilization.
What is independent assortment in meiosis?
Independent assortment refers to the random distribution of maternal and paternal chromosomes into gametes during meiosis, contributing to genetic diversity.
How do mutations affect genetic variation during meiosis?
Mutations can introduce new alleles into a population, and when combined with the processes of meiosis and fertilization, they further enhance genetic diversity among offspring.
What is the primary difference between male and female gametes?
The male gamete (sperm) is smaller and typically has less food reserves compared to the larger female gamete (egg or ovum).
Why is the male gamete designed to travel?
The male gamete is streamlined for mobility, allowing it to swim and reach the female gamete for fertilization.
How do the numbers of gametes produced differ between males and females?
Males typically produce a large number of sperm (millions per ejaculation), while females produce a limited number of eggs (usually one per menstrual cycle).
What is the significance of the large number of sperm produced by males?
Producing many sperm increases the chances of successful fertilization, as only a few sperm may reach the egg.