MODULE 5 Flashcards
Reproduction
The process of creating offspring, either by sexual or asexual processes
sexual reproduction
Reproduction involving two parents who produce offspring that contain a mix of the parents genes and therefore differs from each other and from the parents
- Gametes are produced (meiosis)
- Involves the meeting of special sex cells (gametes)
+Increased variation
-Large time and energy investment
Reproductive success
The ability to produce fertile offspring that survive to reproductive maturity and produce offspring of their own.
Biological fitness
The measure of an individuals reproductive success
Gametes
Carry genetic information from both parents, therefore offspring contain a mix of parental genes
Diploid
Two complete sets
Haploid
Single set
Somatic
Body/Non reproductive cells
Sexual reproduction in animals
The union of male and female gametes (sperm and ova) can occur outside the body (external fertilisation) or inside the body (internal fertilisation)
Internal fertilisation
Takes place inside the body of the female
+Increased likelihood of fertilisation
+Increased protection from environment
-Fewer offspring are produced
External fertilisation
Occurs outside the body, in aquatic or moist terrestrial environments
+Larger number of gametes produced
-Species must produce large numbers of gametes
Sexual reproduction in plants
- flowers are the reproductive organs
- Pollination : male gametes (pollen) are produced and transferred to the female ovules
cross pollination
The transfer of pollen from the anther of a flower of one plant to the stigma of the flower of another plant of the same species
Self-pollination
The pollination of a flower by pollen from the same flower or from another flower on the same plant
seed dispersal
The movement or transport of seeds away from the parent plant.
Germination
The process by which an organism grows from a seed or similar structure.
Sexual reproduction in plants (ADVANTAGES/DISADVANTAGES)
+ genetic diversity within a species -> higher levels of disease resistance -> greater ability to adapt to changing conditions
-Can prevent favourable genes from being passed to offspring
Asexual reproduction in plants e.g. vegetive popagation
Vegetive propagation - When a multicellular structure become detached from the parent plant and develop into new individuals that are genetically identical to the parent plant.
Asexual reproduction in plants (AD/DIS)
+Favourable traits are passed through generations
+Less energy intensive -> population can increase rapidly
-Increase susceptibility of species to new disease
Asexual reproduction - Fungi
Budding - adult organism gives rise to a small bud, which separates from the parent and grows into a new individual.
Asexual reproduction - Spores
Spores - Mitosis produces genetically identical cells to the parent, which are distributed into the environment
