3.1: Understand the Differences Between Sexual and Asexual Reproduction

SEXUAL REPRODUCTION: Involves the Joining of Two Gametes Produced by Meiosis from Two Parents to produce Non - Identical offspring, Inheriting Characteristics from Both Parents

ADVANTAGES	DISADVANTAGES
Increases Variation	Takes Long Time and Energy to Find Mates
Organism can Adapt to New Environments	Not Possible for Isolated Members
Disease is Less Likely to Affect Population (Due to Variation)

ASEXUAL REPRODUCTION: Involves Only One Parent that Produces Offsprings that are Genetically Identical to their Parents by Mitosis

ADVANTAGES	DISADVANTAGES
Population can be Increased Rapidly	Decreases Variation
Can Exploit Suitable Environments Quickly	Vulnerable to Change in Conditions (Can only Exploit Suitable Environments)
	Disease is More Likely Affect Whole Population

3.2: Understand that Fertilisation Involves the Fusion of a Male and Female Gamete to Produce a Zygote that Undergoes Cell Division and Develops into an Embryo

FERTILISATION: Fusion of a Male and Female Gamete to Produce a Zygote that Undergoes Cell Division (Mitosis) and Develops into an Embryo

FERTILISATION

Diagram showing the Process of Fertilisation

EXPLANATION: An Egg Cell and Sperm Cell are Haploid Cells, Containing 23 Chromosomes Each (Half of the 46 Chromosomes Needed to Form a Zygote) When Fertilisation Occurs, the Fertilised Egg Cell will Form a Zygote, a Diploid Cell with 46 Chromosomes (23 Chromosomes from Each Gamete) The Zygote will Contain a Mixture of Genetic Information from Both Parents so will result in Genetic Variation

3.3: Describe the Structure of an Insect - Pollinated and a Wind - Pollinated Flower and Explain How each is Adapted for Pollination

STRUCTURES OF FLOWERS:

STRUCTURE	DESCRIPTION
SEPALS	Protects Unopened lower
PETALS	Brightly Coloured in Insect - Pollinated Flowers to Attract Insects
STAMENS	Male Part of the Flower, Consisting of Filament and Anther
FILAMENT	Positions Anther to Release Male Sex Cell (Pollen Grain)
ANTHERS	Produces and Releases the Male Sex Cell (Pollen Grain)
PISTILS	Female Part of the Flower, Consisting of Ovule, Ovary and Stigma
STIGMA	Top of the Female Part of the Flower which Collects Pollen Grains
OVARY	Produced the Female Sex Cell (Ovum)
NECTARY	Produces a Sugary Solution Called Nectar in Insect - Pollinated Flowers to Attract Insects

INSECT POLLINATED FLOWER: Flower that Requires Pollen to be Distributed by Insects

Diagram:

                                           

ADAPTATIONS

FEATURE	EXPLANATION
PETALS	Large and Brightly - Coloured to Attract Insects
SCENT AND NECTAR	Scented Nectar to Attract Insects
NUMBER OF POLLEN GRAINS	Moderate - Insects Transfer Pollen Grains Efficiently (High Chances of Pollination)
POLLEN GRAINS	Sticky and Spiky to Hang onto Insects
ANTHERS	Inside Flower, Stiff and Firmly Attached to Brush Against Insects
STIGMA	Inside Flower, Sticky so Pollen Grains Stick to it When an Insect Brushes Past

WIND POLLINATED FLOWER: Flowers that Require Pollen to be Distributed by Wind

Diagram:

 

ADAPTATIONS

FEATURE	EXPLANATION
PETALS	Small and Dull (Green or Brown) as they Do Not Need to Attract Insects
SCENT AND NECTAR	No Scented Nectar as they Do Not Need to Attract Insects
NUMBER OF POLLEN GRAINS	Large Amounts - Most Pollen Grains are Not Transferred to Another Flower (Increase Chances of Pollination)
POLLEN GRAINS	Smooth and Light so can Easily be Carried by Wind
ANTHERS	Outside Flower, Loose on Long Filaments to Release Pollen Grains Easily
STIGMA	Outside Flower, Feathery to Catch Drifting Pollen Grains

3.5: Understand the Conditions Needed for Seed Germination

GERMINATION: Process Controlled by Enzymes in Which the Seed Develops into a Plant

Diagram:

                                                           

STRUCTURE:

STRUCTURE	DESCRIPTION
EMBRYO	Young Root (Radicle) and Shoot (Plumule) that will Become the Adult Plant
FOOD STORE	For Aerobic Respiration to Release Energy for Growth of Seed, E.g, Growth of Roots
SEED COAT	Optimum Temperature for Enzymes to Increase Growth Rate and Enzyme Activity

CONDITIONS NEEDED FOR SEED GERMINATION:  

FEATURE	EXPLANATION
WATER	Allows the Seed to Swell with Water and Activates Enzymes to break down the Food Reserves in Seeds (Starch)
OXYGEN	For Aerobic Respiration to Release Energy for Growth of Seed, E.g, Growth of Roots
WARMTH	Optimum Temperature for Enzymes to Increase Growth Rate and Enzyme Activity

3.4: Understand that the Growth of the Pollen Tube followed by Fertilisation Leads to Seed and Fruit Formation

MALE GAMETE IN PLANTS: Pollen Grain  

FEMALE GAMETE IN PLANTS: Ovum

SEED AND FRUIT FORMATION

Diagram showing How a Seed and Fruit is Formed

EXPLANATION: Pollen Grain will Land on Stigma Pollen Tube Grows Out of the Pollen Grain and Down the Style into the Ovary into the Ovule The Male Nucleus Travels Down this Tube from the Pollen Grain and Fuses with the Female Egg Nucleus in the Ovule to Form a Zygote, Zygote will Undergo Mitosis to Develop to Form a Seed Ovule will become the Seed, Ovule Wall will Become the Seed Coat Ovary will become the Fruit

3.7: Understand that Plants can Reproduce Asexually by Natural Methods (illustrated by Runners) and by Artificial Methods (illustrated by Cuttings)

ASEXUAL REPRODUCTION: Involves Only One Parent that Produces Offsprings that are Genetically Identical to their Parents by Mitosis

RUNNER (NATURAL)	CUTTINGS (ARTIFICIAL)
Diagram showing Runners (Branches) in a Spider Plant	Diagram showing the Process of Cuttings
Some Plants Grow Side Branches that Contain Plantlets which Specialise into Forming Root Hair Cells when they Touch the Ground These Plantlets will Grow Roots and Plants will Grow, Allowing Asexual Reproduction	Tissue Sample is Scraped from Parent Plant Tissue Samples are Placed in Agar Growth Medium Containing Nutrients and Auxins Samples Develop into Tiny Plantlets Plantlets are Planted into Compost

3.6: Understand How Germinating Seeds Utilise Food Reserves until the Seedling can Carry Out Photosynthesis

GERMINATION: Process Controlled by Enzymes in Which the Seed Develops into a Plant

UTILISATION OF FOOD RESERVES IN SEEDS

Diagram showing Reactions that Take Place in the Cotyledon (Food Store)

EXPLANATION: Cotyledon contains Starch which is Used as a Food Store in Seeds Amylase will Break Down Starch Into Glucose Glucose will be Used in Aerobic Respiration to Release Energy for Growth This will Continue until the Seed Germinates and can Photosynthesize Independently

3.8: Describe the Structure and Explain the Function of the Male and Female Reproductive Systems

MALE REPRODUCTIVE SYSTEM: The Male Reproductive System includes the  Testes, Glands, Sperm Ducts, Urethra and Penis

Diagram:

                        

STRUCTURE:

STRUCTURE	DESCRIPTION
SEX GLAND	Produces Fluids called Semen that will Provide the Sperm Cells with Nutrients
SPERM DUCT	Sperm Passes through the Sperm Duct to be Mixed with Fluids Produced by the Sex Gland
URETHRA	Tube Inside the Penis that can Carry Out Urine or Semen, a Ring of Muscle in the Urethra Prevents the Urine and Semen from Mixing
TESTIS	Contained in a Bag of Skin (Scrotum) and Produces Sperm (Male Gamete) and Testosterone (Hormone)
PENIS	Passes Urine Out of the Body from the Bladder and Allows Semen to Pass into the Vagina of a Woman during Sexual Intercourse

FEMALE REPRODUCTIVE SYSTEM: The Female Reproductive System includes the  Ovaries, Oviduct, Uterus, Cervix and Vagina

Diagram:

                      

STRUCTURE:

STRUCTURE	DESCRIPTION
OVIDUCT	Connects the Ovary to the Uterus and is Lined with Ciliated cells to Push the Released Ovum Towards the Uterus for Fertilisation
OVARY	Contains Ova (Female Gametes) which Will Mature and Develop when FSH is Released
UTERUS	Muscular Bag with a Soft Lining where the Fertilised Egg Cell will be Implanted to Develop into a Fetus
CERVIX	Ring of Muscle at the Lower End of the Uterus to Keep the Developing Fetus in Place during Pregnancy
URETHRA	Tube that Passes Urine Out of the Body from the Bladder
VAGINA	Muscular Tube that Leads to the inside of the Woman’s Body, Where the Male’s Penis will Enter during Sexual Intercourse