The biological process by which offspring are produced from their parent or parents
Types of reproduction
Asexual reproduction
Sexual reproduction
Asexual reproduction
Does not involve gametes, instead parts of mature organism may develop to new individuals
Offspring is genetically identical to the parent
Binary fission
1. Separation of the body into two new bodies
2. Common in single-celled organisms
Budding
1. A new organism develops from as an outgrowth from the parent body known as bud
2. Once grown, the new organisms detaches from the parent body
Organisms with asexual reproduction
Hydra
Saccharomyces cerevisiae
Fragmentation
The parent body will break into several pieces where each piece grows into a new individual
Vegetative propagation
1. A plant part such as stems, leaves, roots or turions are used to reproduce new plant
2. Natural vegetative propagation (without human interference)
3. Artificial vegetative propagation (with the need of human interference)
Sexual reproduction
Use of sex cells (gametes)
Involves the fusion of male and female gametes to form a zygote
Genetic variability
Gametogenesis
Production of gametes
Blastocyst
Will secrete HCG (hormone used to detect pregnancy)
Progesterone level is very high to prevent menstruation
Embryonic stage
1. Formation of 4 membranes that supports, protects and nourish the embryo (yolk sac, allantois, amnion and chorion)
2. Development of placenta
3. Organ formation
Fetal stage
Organs differentiate further and grow
Gonadotropin-releasing hormone (GnRH)
Stimulates the release of 2 hormones: Luteinizing hormone (LH) and Follicle-Stimulating Hormone (FSH)
Follicle-Stimulating Hormone (FSH)
Male: It causes the testes to produce sperm
Female: it causes the growth of an ovarian follicle and it causes the follicle cells to secrete estrogen
Luteinizing hormone (LH)
Male: It causes the testes to secrete testosterone
Female: it causes ovulation and to secrete progesterone
Stamen
Male portion of a flower
Made up of an anther and a filament
The anther produces haploid pollen grains by meiosis
Most flowers have multiple stamens
Carpel/Pistil
Female portion of a flower
Stigma - sticky; to trap pollen
Style - hollow tube which connects stigma and ovary
Ovary - produces female gametes (ovules)
Nutrition
Nutrients help living organisms develop their bodies, grow, heal damaged body parts and give energy for life and activity
Monoecious
Stamens and pistils occur on separate flowers, but the same plant
Dioecious
Staminate and pistillate flowers occur on separate plants
Modes of Nutrition
Autotrophic Nutrition
Heterotrophic Nutrition
Gametophyte
Stage of the life cycle of a plant that is haploid; stage that produces gametes via mitosis; these gametes fuse to form a zygote that develops into a sporophyte
Sporophyte
Stage of the life cycle of a plant that is diploid; it is the most recognizable structure in most flowering plants; it produces haploid spores by meiosis in structures called sporangia
Autotrophic Nutrition
Can produce their own food
Male gametophyte
Inside the anthers' microsporangia, male gametophytes divide by meiosis to generate haploid microspores, which, in turn undergo mitosis and give rise to pollen grains (containing 2 sperm nuclei and tube nucleus)
Pollen grains
Contains two cells: one generative cell and one cell that will become the pollen tube cell
Heterotrophic Nutrition
Cannot produce their own food
Female gametophyte
The ovule inside the ovary contains the megasporangium
Within each mega sporangium, a megasporocyte undergoes meiosis generating four(4) megaspores; three (small) and one (1) large
Digestion
The mechanical and chemical processes by which complex food substances are broken down into simpler substances
Pollination
The transfer of pollen from an anther to a receptive stigma
Agents: Animals, wind, water, humans
Parts of the Digestive System
Mouth
Esophagus
Stomach
Liver
Pancreas
Gall bladder
Small Intestine
Large Intestine
Anus
Fertilization
One egg and sperm combine, forming a diploid zygote, the future embryo
Double fertilization - fuses with the polar nuclei to become the endosperm, which serves as food of the early embryo
Embryo development
Ovules become the seed
Ovary matures into fruit
Mouth
Produces saliva where mechanical mastication of food takes place to form bolus
Seed germination
Germination - is the resumption of growth and development after a period of seed dormancy
Epigenous germination
Hypogenous germination
Esophagus
A muscular tube that conducts peristalsis and serves a passage way for food
Hormonal regulation of plant growth and development
Stomach
A muscular sac that contains gastric juices that helps to break down the food chemically
Liver
Produces the bile that helps in the digestion of fats