reproduction Flashcards
asexual reproduction
process resulting in genetically identical offspring from one parent
advantages and disadvantages of asexual reproduction
Advantages:
- Saves time and energy (only one parent needed)
- Quick reproduction
- Farming - crops can be reproduced very easily AND offspring will have the same desirable characteristics as parents (eg. A specific fruit)
Disadvantages:
- Evolution NOT possible - makes species more vulnerable to environmental changes (eg. Diseases)
sexual reproduction
- Process involving the fusion of the nuclei of two specialized sex cells to form genetically different offspring
fertilization def.
the fusion of the nucleus of the male gamete (sperm cell) with the nucleus of the female gamete (egg cell/ovum) to produce a zygote.
haploid meaning
nucleus of a gamete
single set of unpaired chromosomes
diploid meaning
nucleus of a zygote
two sets of chromosomes (one from each parent)
advantages and disadvantages of sexual reproduction
Advantages:
- Evolution/variation possible
- Selective breeding - farmers producing crops can choose the best characteristics from two different strains to produce new varieties of plant
Disadvantages:
- Takes time and energy
pollination meaning
the transfer of pollen grains from the anther to the stigma
male part in a flower
stamen
consists of an anther and filament
female part in a flower
carpel
consists of a style, ovary and stigma
sepal function
to protect the growing flower and help to stop it drying out
petal function
to attract insects, birds or mammals to carry out pollination
stamen function
to produce male gamete (pollen) and provide the correct structures and conditions necessary for the transfer of pollen
filament function
to hold the anther in a position where it is able to transfer pollen to an insect, mammal or bird
anther function
to produce pollen which contains the male gamete
stigma function
to trap pollen from other flowers
style function
to support and present the stigma in a position where it can receive pollen from an insect, bird or mammal
carpel function
to produce female gametes and provide the right structures and conditions necessary for fertilization
ovary function
contains ovules (which contains the female gamete) which will develop into seeds after fertilization
ovule function
female gametes are produced and contained within the ovules.
self-pollination meaning
- The transfer of pollen from the anther of a flower to the stigma of the same flower or a different flower on the same plant
self-pollination advantages and disadvantages
Advantage: no need to rely on pollinators, flowers may grow in areas where pollinators may not live
Disadvantage: no variation
cross-pollination meaning
The transfer of pollen from the anther of one flower to the stigma of another flower on a different plant of the same species