D3.1 Reproduction

• Asexual reproduction uses mitosis without gametes or fertilization, producing clones

• Sexual reproduction uses meiosis and fertilization to generate genetic variation

• Meiosis produces haploid gametes and prevents chromosome doubling each generation

• Random fertilization fuses gametes to form unique diploid zygotes

• Male gametes are small, numerous, and usually motile

• Female gametes are larger, fewer, and contain resources for early development

• Male structures include testes, epididymis, sperm duct, glands, urethra, and penis

• Female structures include ovaries, oviducts, uterus, endometrium, cervix, vagina, and vulva

• FSH, LH, oestradiol, and progesterone coordinate ovarian and uterine cycles

• Follicle growth, ovulation, corpus luteum, endometrium build-up, and menstruation are linked

• Fertilization occurs in the oviduct after sperm reaches the egg

• Sperm and egg nuclei fuse so paternal and maternal chromosomes form the zygote genome

• IVF uses hormones to stimulate superovulation and control egg maturation

• Eggs are collected, fertilized outside the body, and embryos transferred to the uterus

• Flowering plants produce male gametes in pollen and female gametes in ovules

• Pollination, pollen-tube growth, and fertilization produce embryos inside seeds

• Insect-pollinated flowers often have petals, scent, nectar, sticky pollen, and sticky stigma

• Floral structures position pollinators to transfer pollen from anther to stigma

• Cross-pollination increases variation by transferring pollen between different plants

• Mechanisms include dioecy, self-incompatibility, and different maturation times

• Self-incompatibility prevents pollen from fertilizing ovules of the same plant

• Recognition systems block self-pollen growth and reduce inbreeding

• Seed dispersal reduces competition with parent plants and spreads offspring

• Germination uses water uptake, enzyme activation, and food reserve mobilization