16. Reproduction

• Define asexual reproduction as a process resulting in the production of genetically identical offspring from one parent

• Identify examples of asexual reproduction from information provided

• Discuss the advantages and disadvantages of asexual

reproduction:

– to a population of a species in the wild

– to crop production

• Define sexual reproduction as a process involving the fusion of the nuclei of two gametes (sex cells) to form a zygote and the production of offspring that are genetically different from each other

• Define fertilisation as the fusion of gamete nuclei

• State that the nuclei of gametes are haploid and that the nucleus of a zygote is diploid

• Discuss the advantages and disadvantages of sexual reproduction:

– to a population of a species in the wild

– to crop production

• Identify and draw, using a hand lens if necessary, the sepals, petals, stamens, filaments and anthers, carpels, style, stigma, ovary and ovules, of an insect-pollinated flower

• State the functions of the sepals, petals, anthers, stigmas and ovaries

• Use a hand lens to identify and describe the anthers and stigmas of a wind-pollinated flower

• Distinguish between the pollen grains of insect-pollinated and wind-pollinated flowers

• Define pollination as the transfer of pollen grains from the anther to the stigma

• State that fertilisation occurs when a pollen nucleus fuses with a nucleus in an ovule

• Describe the structural adaptations of insect-pollinated and wind-pollinated flowers

• Investigate and state the environmental conditions that affect germination of seeds, limited to the requirement for water, oxygen and a suitable temperature

• Define self-pollination as the transfer of pollen grains from the anther of a flower to the stigma of the same flower or different flower on the same plant

• Define cross-pollination as transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species

• Discuss the implications to a species of self-pollination and cross-pollination in terms of variation, capacity to respond to changes in the environment and reliance on pollinators

• Describe the growth of the pollen tube and its entry into the ovule followed by fertilisation (details of production of endosperm and development are not required)

• Identify and name on diagrams of the male reproductive system: the testes, scrotum, sperm ducts, prostate gland, urethra and penis, and state the functions of these parts

• Identify and name on diagrams of the female reproductive system: the ovaries, oviducts, uterus, cervix and vagina, and state the functions of these parts

• Describe fertilisation as the fusion of the nuclei from a male gamete (sperm) and a female gamete (egg cell/ovum)

• State the adaptive features of sperm, limited to flagellum and the presence of enzymes

• State the adaptive features of egg cells, limited to energy stores and a jelly coating that changes after fertilisation

• State that in early development, the zygote forms an embryo which is a ball of cells that implants into the wall of the uterus

• State the functions of the umbilical cord, placenta, amniotic fluid

• Outline the growth and development of the fetus in terms of increasing complexity in the early stages and increasing size towards the end of pregnancy

• Describe the antenatal care of pregnant women, limited to special dietary needs and the harm from smoking and alcohol consumption

• Outline the processes involved in labour and birth, limited to:

– breaking of the amniotic sac

– contraction of the muscles in the uterus wall

– dilation of the cervix

– passage through the vagina

– tying and cutting the umbilical cord

– delivery of the afterbirth

• Compare male and female gametes in terms of size, structure, motility and numbers

• Explain the adaptive features of sperm, limited flagellum, mitochondria and enzymes in the acrosome

• Explain the adaptive features of egg cells, limited to energy stores and a jelly coating that changes after fertilisation

• Describe the function of the placenta and umbilical cord in relation to exchange of dissolved nutrients, gases and excretory products and providing a barrier to toxins and pathogens (structural details are not required) pregnancy

• State that some toxins, e.g. nicotine, and pathogens, e.g. rubella virus, can pass across the placenta and affect the fetus

• Discuss the advantages and disadvantages of breast-feeding compared with bottle-feeding using formula milk

• Describe the roles of testosterone and oestrogen in the development and regulation of secondary sexual characteristics during puberty

• Describe the menstrual cycle in terms of changes in the ovaries and in the lining of the uterus

• Describe the sites of production of oestrogen and progesterone in the menstrual cycle and in pregnancy

• Explain the role of hormones in controlling the menstrual cycle and pregnancy, limited to FSH, LH, progesterone and oestrogen

• Outline the following methods of birth control:

– natural, limited to abstinence, monitoring body temperature and cervical mucus

– chemical, limited to IUD, IUS, contraceptive pill, implant and injection

– barrier, limited to condom, femidom, diaphragm

– surgical, limited to vasectomy and female sterilisation

• Outline the use of hormones in contraception and fertility treatments

• Outline artificial insemination (AI)

• Outline in vitro fertilisation (IVF)

• Discuss the social implications of contraception and fertility treatments

• Define sexually transmitted infection as an infection that is transmitted via body fluids through sexual contact

• State that human immunodeficiency virus (HIV) is an example of an STI

• Explain how the spread of STIs is controlled

• Describe the methods of transmission of HIV

• State that HIV infection may lead to AIDS

• Outline how HIV affects the immune system, limited to decreased lymphocyte numbers and reduced ability to produce antibodies