Biology Reproduction & Growth

Learning Intentions What is sexual reproduction? What process leads to the formation of gametes? What structures and steps are involved in Sexual Reproduction in Animals? Describe growth and development in animals

1 Sexual Reproduction Sexual Reproduction is when new offspring are made from male and female parents The offspring receive 50% genetic information from the mother and 50% genetic information from the father Variation occurs as all the offspring are different Variation is important for the survival of the species so it can adapt to a changing environment

Cell Division: Meiosis (2:15) 2 Gamete Formation Each body cell (eg. Skin cell) contains 46 chromosomes Each body cell has 2 sets of chromosomes (diploid) New body cells are made by the process of mitosis A sex cell (eg. sperm) contains 23 chromosomes Each sex cell has 1 set of chromosomes (haploid) Sex cells are also called gametes New gametes are made by the process of meiosis Meiosis is important because it ensures that a single set of chromosomes are produced in gametes (haploid) Cell Division: Meiosis (2:15)

3a) Sexual Reproduction in Animals Male Reproductive System Structure

3b) Sexual Reproduction in Animals Male Reproductive System Structure & Function Structure Function Testes Produce sperm Penis Organ that releases sperm into the vagina Sperm Duct Allows sperm to travel from the testes to the penis Sperm Male gamete

3c) Sexual Reproduction in Animals Female Reproductive System Structure

3d) Sexual Reproduction in Animals Female Reproductive System Structure & Function Structure Function Ovary Produces eggs Oviduct Allows the passage of eggs from the ovary to the uterus Fertilisation occurs here Vagina During sexual intercourse the penis releases sperm in here Uterus If fertilisation occurs, the embryo implants here Egg Female gamete

3e) Fertilisation in Animals Fertilisation is when the NUCLEUS of a sperm cell FUSES with the NUCLEUS of an egg cell Sperm (3:04) Egg (1:44) Fertilisation (2:04) Which gamete contains a food store? Which gamete contains lots of mitochondria?

4. Internal V External Fertilisation Internal Fertilisation Internal fertilisation is when sperm are released inside the body of the female and fertilisation occurs in the oviduct e.g. Humans External Fertilisation External fertilisation is when sperm and eggs are released into the environment (e.g. water) and fertilisation takes place outside of the bodies e.g. Fish

5a) Development in Animals - Exchange Carbon Dioxide & urea from foetus to mother Oxygen, Glucose, Water, Antibodies, Hormones, Drugs from mother to foetus The placenta allows exchange of materials between the mothers and foetus’s blood Glucose and Oxygen are transported from the Mother to the Foetus Carbon Dioxide and Wastes are transported from the Foetus to the Mother Placenta ( 2:46)

5b) Growth & Development (Animals) Teratogens and impact on Development First Trimester (2:24) Second Trimester (2:15) Third Trimester (2:50) Birth (3:40)

5c) Growth & Development (Animals) Research Tasks Find out the impact of the following on growth and development of an embryo and foetus Alcohol Tobacco Drugs Radiation Unhealthy diet

Learning Intentions What structures and steps are involved in Sexual Reproduction in Plants? 7. Describe growth and development in plants 8. Describe asexual reproduction in plants How can humans artificially reproduce organisms to mass produce large yields of crops, fuels and medicines?

6a) Sexual Reproduction in Plants Flower Structure Pollen (0:50)

6b) Sexual Reproduction in Plants Flower Structure & Function Structure Function Sepal Protects the bud Petal Attracts insects Anther Produces pollen Pollen The male gamete Stigma Landing platform for trapping pollen Ovary Produces ovules Ovule The female gamete

7a) Growth & Development (Plants) Pollination is when pollen lands on the sticky stigma Pollen can be transferred by WIND or INSECTS Self-pollination Pollination involving one plant Cross-pollination Pollination involving two plants Describe the difference in appearance between a wind & insect pollinated flower

7b) Growth & Development (Plants) Fertilisation Pollination occurs A pollen tube grows from the stigma to the ovary The nucleus of the pollen grain travels down the pollen tube The nucleus of a pollen grain fuses with the nucleus of an ovule (FERTILISATION) The ovule develops into a seed The ovary develops into a fruit Sexual Reproduction (3:23)

7c) Growth & Development (Plants) Seed Dispersal Seeds need to be dispersed away from each other to reduce competition for root space, soil water, light, etc Seeds can be dispersed by:- The wind e.g. Dandelion seed Animal Internal (eating seeds & e.g. Bramble seeds excreting them in faeces) Animal External (seeds being hooked onto animal fur then dropping off) e.g. Burdock seeds

7d) Growth & Development (Plants) Seed Structure & Function Germination is when the embryo grows a shoot and Root. Seeds need Water, Oxygen & Warmth (WOW) to germinate The Seed Coat protects the food store from being Eaten by bacteria and fungi in the soil The Food Store provides the embryo with an Energy source for growth The Embryo grows into the shoot and root

7e) Growth & Development (Plants) Plant Life Cycle Germination Seed Dispersal Growth Fruit Formation Pollination Fertilisation

8) Asexual Reproduction in Plants Asexual Reproduction is when ONE plant can make identical copies of itself Asexual Reproduction (2:57) Potatoes produce TUBERS Tubers are underground food stores that grow into new potato plants Daffodils produce BULBS Bulbs are underground food stores that grow into new daffodil plants Strawberries produce RUNNERS RUNNERS are long thick stems with new plantlets at the end What name is given to organisms that are identical to their parents?

9 Artificial Reproduction in Plants Artificial Reproduction is when humans are involved in reproducing organisms:- e.g. Humans taking a cutting in plants to mass produce plants Cut a 10cm stem of Geranium Cut below a node and remove the lower leaves (to prevent water loss through stoma pores) Dip cutting into rooting powder (to encourage root growth) Place cutting into rooting compost and firmly press the compost (to stabilise the soil) Water the compost Place pot in a propagator or poly bag to increase the humidity