UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” Título

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. Reproduction is the process that allow living things to create new individuals which are similar to the parents. There are three types of reproduction: ● Asexual Reproduction: Offspring are created from only a single individual, so this is genetically identical to the parent and to the brothers. ● This type of reproduction can be through: ● -Fragmentation: The parent divides into a serie of fragments that develop into new individuals, such as, starfish. ● -Budding: A group of cells generate a protuberance or bud on the surface of the parent´s body, from which a new individual develops. Sometimes the remains joined to the parent forming a colony. This reproduction appears in sponges.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Asexual Reproduction: ● Fragmentation Budding

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Sexual Reproduction: In this is necessary two individual of different sex, a female and a male, which produce cells specialized in reproduction, the gametes, in special organs, the gonads. ● When two gametes from individual of different sex fuse together, fertilisation, to create a zigote, which divides many times to originate a new organism which is a mix between the two parents. ● Some species are hermaphrodites, then they have the two sexes in the same individual, such as snails.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Sexual Reproduction:

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Sexual Reproduction: Hermaphrodit organisms

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Alternating Reproduction: In this type of reproduction there is a generation which reproduces asexually and another generation which reproduces sexually, for example some cnidarians.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 1.REPRODUCTION IN ANIMALS. ● Advantages and disadvantages of sexual and asexual reproduction. ● - Two individuals are needed for sexual reproduction. In asexual reproduction a single organism can genetate many offsprings. ● - In sexual reproduction individuals are genetically differents, so is easier that some of them are able to survive. In asexual reproduction there isn´t diversity. ● - Sexual reproduction favours biodiversity, because in each generation the changes are accumulated.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 2. REPRODUCTION IN PLANTS. There are three possible types of reproduction: ● Vegetative Reproduction: It is a type of asexual reproduction, and it can be in two ways: ● - Natural vegetative Reproduction, where bulbs, tubers, stolons and rhizomes, produced by a plant can generate new plants. ● - Artificial Vegetative Reproduction, is carried out by people: by taking a cutting, by layering or by grafting.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 2. REPRODUCTION IN PLANTS. ● Sexual Reproduction: In flowering plants, flowers are the reproductive organs. ● The flowers have the following structures: ● - Stamens, are the male reproductive system. ● - Pistil, is the female reproductive system, and it is composed of ovary, style and stigma.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 2. REPRODUCTION IN PLANTS. ● Sexual Reproduction: ● -Pollination: This is the process by which pollen grains are transferred from the staments to the stigma of the pistil. ● *Self-pollination occurs when the pollen from a flower falls onto the stigma at the same plant. ● *Cross-pollination occurs when the pollen falls on the stigma of a different plant.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 2. REPRODUCTION IN PLANTS. ● Sexual Reproduction: Pollination.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 2. REPRODUCTION IN PLANTS. ● Alternating Reproduction: There are two types of individuals alternate: Gametophytes which produce gametes, and Sporophytes which form spores. ● This reproduction takes place in non-flowering plants, such as mosses and ferns.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 3. INTERACTION IN ANIMALS. Living things interact with their surroundings because they detect changes in their environment and respon to them with movements or changes in behaviour. There are two types of coordination to response the stimulus: ● Nervous coordination: Receptor organs detect stimulus and send the information to the nervous system, which processes it, chooses an appropiate response, and then sends an order to the effector organs (muscles and glands) which carry out the order. ● The response can be movement or secretion of a substance. ● The encephalon (cerebrum, cerebellum and brain stem), and spinal cord are both nervous centres. ● Involuntary responses, reflex actions, are controlled by spinal cord.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 3. INTERACTION IN ANIMALS ● Nervous coordination:

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 3. INTERACTION IN ANIMALS. ● Hormonal coordination: The endocrine system is a system of glands which respond to certain stimuli and produce and release hormones into the blood. Each hormone works on a particular effector organ or tissue and produces a specific response.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 4. INTERACTION IN PLANTS. Plants detect stimuli in their surroundings and respond to them. The photoperiod controls many of the plant´s activities, such as, when the leaves fall, or when the plant produces flowers. The main responses are: ● Tropic movements: These are permanent growth movements which depend on the direction of the stimulus, for example, light (phototropism), gravity (geotropism), or humidity (hydrotropism). ● Nastic movements: These are movements of some plant´s structures, such as, the leaves or flowers. They are not permanent movements and the direction of response doesn´t depend on the direction of the stimulus.

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 4. INTERACTION IN PLANTS. ● Nastic movements:

UNIT 9 “THE FUNCTIONS OF LIVING THINGS II” 4. INTERACTION IN PLANTS. Many plants also have tactile responses: they respond to touch. Some climbing plants have tendrils, which are stems or modified leaves. When the tendril touches an object, it grows and twists around it. Tendrils