Asexual Reproduction Types

• Reproduction is how parents create new species called offspring.
• Reproduction comes in two forms: sexual, and asexual.
• Two parents are required for sexual reproduction.
• One parent can produce offspring via asexual reproduction.
• Asexual reproduction is common in plants, however is less common in animals.

Types of asexual reproduction

• Bacteria and amoeba use binary fission
• The parent bacteria’s DNA replicates, cell divides in halves with each half having DNA.
• The parent cell divides into two identical daughter cells.
• Budding is an asexual reproduction process where the offspring grows from a bud
• Budding is common in Echinodermata and hydra.
• Buds fall off the parent once large enough, and become independent.
• Fragmentation is an asexual reproduction where the parent splits into several segments.
• Starfish are an example - where an entirely new organism may be produced by a part of its body, such as its arm.
• Parthenogenesis is where the female organism generates eggs without fertilization and offspring emerge.
• Lizards, some fish and a few insects use this method.
• This asexual reproduction method is seen in both plants and animals, but is not seen in mammals.

Types of asexual reproduction in plants

• Vegetative propagation takes place in stems of certain plants.
• Buds that emerge on their leaves or stems give rise to new plants.
• Examples: tuber (potato), bulb (onion), stolon/runner (strawberry), rhizome (ginger), sucker (banana), stem cutting (rose), leaf (welcome plant).
• Sexual Reproduction involves two separate parents that are of the opposite sex.
• Both plants and animals exhibit sexual reproduction.
• Flowering plants undergo sexual reproduction.

The Flower

• The flower is the sexual reproductive organ in plants.
• The flower's parts: calyx, corolla, androecium, and gynoecium

The Calyx

• Green petal-like structures are located right above the receptacle (base of flower).
• The calyx is composed of sepals, that protect the flower while it is a bud.

The Corolla

• The term for the collective colorful petals of the flower.
• The petals attract pollinating agents and are often fragrant.
• The corolla is found above the calyx layer.

The Androecium

• The male reproductive section of a flower.
• It consists of a series of stamens that consist of a filament and anther.
• The anthers are structures that produce the male gamete-containing pollen.

The Gynoecium

• The female reproductive organ of the flower.
• It is composed of the ovary, style, and stigma.
• The style is a slender filament on top of which lies the stigma.
• The stigma retains pollen grains that are transferred.
• Once pollen lands on the stigma, it is moved to the ovary via the style.
• The ovary is lobed and composed of the female gamete-containing ovules.

Pollination and Fertilization

• Pollen grains and ovules cannot travel by themselves.
• Wind, water, or animals, enable the pollen grains to travel and reach the stigma of the same or another flower.
• Fertilization is a sexual reproduction process that occurs after pollination and germination in plants.
• Fertilization can be defined as the fusion of the male gametes (pollen) to form a diploid zygote with the female gametes (ovum).
• This physicochemical mechanism happens after the carpel is pollinated and develops into a deed in the zygote.
• Flowers important for fertilization as they are angiosperm reproductive structures (flowering plants).
• When gametes in haploid conditions fuse a diploid zygote is created.
• After pollination of the carpel, the pollen grain germinates and evolves into the style, forming a pathway to transfer the pollen grain down to the ovary.

Types of Fertilization

• Fertilization is grouped into three types based on pollen tube entry into the ovule.
• The types are: porogamy, chalazogamy, and mesogamy.
• Porogamy, the pollen tube enters the ovule through the micropyle.
• Porogamy is common in angiosperms or flowering plants.
• Chalazogamy fertilization occurs on all Casuarina species of plants.
• In chalazogamy the pollen tube enters the ovule through the pollen tube.
• Mesogamy fertilization is seen in all Cucurbit plants (pumpkin, ridge gourds, bitter gourd, etc.).
• In mesogamy, the pollen tube enters the ovule through the middle part/integuments of the ovule.
• Double fertilization fuses two male gametes with a female gametophyte.
• One sperm cell fuses with the egg-producing zygote, the other fuses to create the endosperm with the two polar nuclei.
• Both angiosperm plants undergo this dual process of fertilization.

Reproduction in Human Beings

• In humans, reproduction occurs through sexual reproduction.
• Both male and female gametes fertilize to create a zygote that develops into an embryo.
• Fertilization occurs within the female's body, called internal fertilization.

Male Reproductive System

• The penis is used for sexual intercourse and urination.
• Semen and urine leave the penis through the urethra.
• The scrotum covers the testicles, hangs behind the penis, and maintains optimum temperatures for sperm survival and function.
• Sperms produce when testicles is slightly cooler than body temperature.
• Muscles in the scrotum move the testicles close to the body.
• Located at the back of the testis is the epididymis that binds to the vas deferens, stores/carries sperm.
• The testis is the site of testosterone production.
• Seminiferous tubules are the coiled tubes within the testicles where spermatogenesis takes place.
• The male reproductive system's internal organs are called accessory organs and include the vas deferens, prostate gland, seminal vesicles, and bulbourethral (Cowper's) glands.
• The vas deferens transports mature sperm to the urethra during ejaculation.
• Seminal vesicles are sac-like pouches near the base of the bladder that produces energy for sperm, like fructose.
• The majority of a man's ejaculate consists of the seminal vesicle fluid.
• The prostate gland, walnut-sized in front of the rectum below the urinary bladder, adds extra sperm nourishing fluid to the ejaculate.
• Bulbourethral (Cowper's) glands are pea-sized structures below the prostate gland.
• These glands have a clear fluid that empties into the urethra directly to lubricate and neutralize residual urine acidity.

The Female Reproductive System

• The main parts of the human female reproductive system: the uterus and the ovaries, which contain egg cells.
• The uterus hosts the fetus and also produces vaginal and uterine secretions; it passes sperm to the fallopian tubes.
• The ovaries produce female eggs and secrete progesterone and estrogen.
• Internal Sections: the vagina (contains the labia, clitoris, and urethra, and enters the external organs at the vulva), connects to the uterus via the cervix while the uterus is attached to the ovaries via the fallopian tubes.
• The ovaries produce an ovum at certain times sent into the uterus through the fallopian tube.
• If it meets sperm it merges with the egg, fertilizing it in the oviducts/in the uterus itself.
• Then, the zygote implants in the uterine wall, where embryogenesis and morphogenesis starts.
• Developed enough to survive outside the womb the cervix dilates and uterine contractions drive the fetus through the birth canal (vagina).
• The ova are larger than sperm and are formed by the time a female baby is born.
• In anticipation of fertilization, an oogenesis process matures one ovum approximately every month sent down the fallopian tube attached to its ovary.
• If the egg is not fertilized it is flushed out of the system via menstruation.
• The vagina, uterus, fallopian tubes, cervix, and ovary are the anatomically female inner reproductive organs.
• The external components are Mons pubis, pudendal cleft, labia majora, labia minora, Bartholin's glands, and clitoris.

Fertilization and Early Embryonic Development in Humans

• Fertilization and early embryonic development is complex, an organism grows from a single-celled zygote into a multi-cellular organism.
• Embryonic development early stages are important for health of the body.
• Fertilization is the process of the egg and sperm fusing to form a zygote.
• There is one set of chromosomes each in the egg and sperm, one from each must unite so the child has only one diploid set of chromosomes.
• Zona pellucida protects the egg via an extracellular matrix.
• When a sperm binds to the zona pellucida acrosomal reactions occur via a series of biochemical processes.
• The acrosome produces enzymes and initiates the breakdown of the glycoprotein matrix to enable the plasma sperm membrane to fuse with the egg plasma membrane.
• The egg releases proteins until acrosomal reactions occur to prevent other sperm from fusing.
• If the mechanism fails it results in polyspermia, where multiple sperm fuse with the egg.
• Resulting in a non genetically viable embryo that dies within a couple of days.

Cleavage and Blastula Stage

• A single-celled zygote begins the growth of multi-cellular species by undergoing rapid cell division (cleavage) to form the blastula.
• After over 100 cells have been formed by cleavage, the embryo is called a blastula.
• The blastula is a spherical layer of cells around a fluid-filled or yolk-filled cavity (the blastoderm) (the blastocoel).
• Mammals here form a blastocyst with a different inner cell mass.
• Cells divide during cleavage without increasing in mass i.e., one large single-celled zygote divides into many smaller cells.
• Each cell is a blastomere inside the blastula.

Gastrulation

• Cells in the blastula are rearranged spatially to create three layers of cells via gastrulation.
• The blastula folds upon itself during gastrulation to form the three cell layers called germ layers.
• The layers: endoderm, the ectoderm, and the mesoderm.
• The ectoderm gives rise to the epidermis and the nervous system.
• The mesoderm produces the body's muscle cells and connective tissue.
• The endoderm gives rise to columnar cells and several internal organs (digestive system).

Organogenesis

• Organs form from the germ layers via differentiation.
• Embryonic stem cells express unique sets of genes, which decide their ultimate type of cell.
• Genes will be expressed by certain cells in the ectoderm to create skin cells, resulting in epidermal cells.
• In vertebrates, the development of the neural system is one of the key steps.
• Epithelial cells and tissues, and neural tissues, form the ectoderm.
• Growth factors signal cells at the edge of the ectoderm to become epidermis cells and create the neural plate.
• If growth factors were to block signaling the entire ectoderm would differentiate into neural tissue.
• The neural plate rolls up to form a neural tube that turns into the brain and spinal cord.
• The mesoderm lying on either side of the neural tube will form animal body's various connective tissues.
• Spatial gene expression pattern reorganizes mesoderm into groups of cells with gaps between them (somites) that will grow into ribs, lungs, and the segmental (spine).

Nutrition

• Nutrition is the mechanism of energy from food.

Types of Nutrition

• There are two broad types of nutrition among living organisms: autotrophic, heterotrophic.

Autotrophic Nutrition

• Species use simple inorganic materials (water, carbon dioxide) to synthesize food with light and chlorophyll.
• Light energy is transformed into food like glucose via photosynthesis.
• The autotroph organisms includes plants, algae, and bacteria (cyanobacteria).

Heterotrophic Nutrition

• Species rely on others for nutrition; heterotrophs cannot produce food on their own and rely on sources/organisms.
• Heterotrophs: fungi, animals (including humans) based on the climate / their adaptations
• There are several types of heterotrophs: herbivores (eat plants), carnivores (eat animals); some are omnivores (eat both).

Nutrition in Plants

• Plant cells require nutrients (essential substances) that are organic / inorganic.
• Organic compounds contain carbon derived from the atmosphere (carbon dioxide)
• Minerals are inorganic substances found in the soil solution: nitrogen (N) Phosphorus (P) and potassium (K) structure and regulation.
• Plants need light, water, 20 elements = essential nutrients for their needs.
• Deficiencies of nutrients can affect the growth of plants, particularly macronutrients.
• Depending on the nutrient, lack can cause stunted development, slow growth or chlorosis (yellow leaves).
• Plants absorb nutrients and water through their root system as well as carbon dioxide from the atmosphere.
• Sunlight, soil nutrients, water, and carbon dioxide enables plants to grow.
• Roots anchor the plant and absorb the necessary mineral elements, nutrients and water from the soil.
• Roots also store food.
• Aerial roots rise above the ground for water.

Nutrition in Animals

• Multi-step process to get nutrition via ingestion (taking in food), digestion, absorption, and elimination.
• Ingestion takes food through the mouth.
• The teeth, saliva, and tongue of vertebrates prepare food into a bolus.
• Saliva enzymes break down the food mechanically and chemically.
• Large food particles are modified into a soft mass which is swallowed and travels down the length of the esophagus.
• Digestion is the mechanical and chemical degradation of food into small organic fragments.
• Macromolecules turn into smaller absorbsable molecules in the digestive epithelium.
• Large molecules of proteins, carbohydrates, and lipids must be reduced to smaller particles (simple sugar) prior to system absorption.
• Different organs perform unique roles during digestion.
• Nutritional balance: the animal diet requires carbohydrates, protein, and fat as well as vitamins and inorganic components.

Carbohydrates

• Digestion begins in the mouth - the salivary enzyme amylase breaks down maltose, a disaccharide, into food starches.
• No carbohydrate digestion in the esophagus (mucus production takes place for lubrication).
• Stomach acid stops amylase.
• Next carbohydrate digestion stage takes place in the duodenum
• Chyme enters duodenum and interacts with the pancreas, liver, and gallbladder digestive secretion.
• Pancreatic juices contain amylase which breaks down starch/glycogen into maltose (disaccharide).
• Maltases, sucrases, and lactases break down disaccharides into monosaccharides
• Maltose breaks down into glucose (via the enzyme maltase.
• Sucrase breaks down glucose/fructose from sucrose ('table sugar').
• Lactase breaks down glucose/galactose from lactose ('milk sugar').
• The monosaccharides (glucose) that are formed are absorbed and used for harnessing energy / metabolic pathways.
• Monosaccharides are transferred through the intestinal epithelium into bloodstream to be transferred to cells.

Protein

• In the stomach, a large part of the digestion of protein takes place.
• The enzyme pepsin breaks down protein & peptides (short chains of amino acids).
• Enzymes like trypsin, elastase, and chymotrypsin act on the peptides in the duodenum, reducing them to smaller peptides.
• Peptidases break down peptides to single amino acids.
• Amino acids are ingested into the tiny intestines into the bloodstream.

Lipids

• Lipid digestion starts in the stomach (lingual lipase - gastric lipase).
• Majority of lipid digestion occurs in the small intestine owing to pancreatic lipase.
• When chyme reaches duodenum, hormone responses cause bile release (formed in liver/stored in gallbladder).
• Bile contains amphipathic bile salts (sections that are hydrophobic and hydrophilic) to digest lipids (triglycerides).
• Emulsification is a mechanism that breaks down large lipid globules into many small lipid globules.
• Hydrophilic side of the bile salts interface with water while the hydrophobic side interfaces with lipids.
• Pancreatic lipases act more effectively on the lipids and digest them after emulsification.
• Lipases break lipids down into glycerides and fatty acids.

Vitamins

• Vitamins are either soluble in water or lipids.
• Lipid soluble vitamins need dietary lipid for absorption.
• Water-soluble vitamins are absorbed from the intestine directly into the bloodstream.

Elimination

• Final digestion stage.
• Undigested food content travels to the large intestine for water absorption.
• Semi-solid waste is transferred by peristaltic muscle movements from the colon into the rectum.
• Rectum expands fecal matter storage activates neural signals and peristaltic motions to remove solid waste via the anus.

Gas Exchange

• Exchange of gases is most essential event in life.
• Carbon dioxide (waste product) is removed and substituted by oxygen in animals.
• Plants take in carbon dioxide in photosynthesis to produce oxygen for cellular respiration.
• Gas exchange maintains oxygen and carbon dioxide in the air.
• CO2 may be a waste product of respiration in plant cells / a by-product used in photosynthesis.
• Gas exchange is a necessity of life & prerequisite for metabolism of energy.
• Diffusion through a moist membrane is the process gas exchange i.e., the movement of molecules in the direction following the concentration gradient (greater to lower).
• The cell membranes are constantly moistened by fluid.

Plants Gases

• Plants exchange gases with the atmosphere.
• Water moves through the tissues of aquatic plants providing the means for carbon dioxide exchange.
• Air enters terrestrial plants tissues and carbon dioxide gases diffuse through the inner cell moisture.
• Carbon dioxide in leaves must be abundant, oxygen from photosynthesis must be released.
• Gases pass through pores referred to as stomata in the epidermis (not through the leaf cuticle).
• The lower leaf surface stomata are abundant and open during the day when photosynthesis is highest.
• Physiological changes in the surrounding guard cells regulate stomata opening and closure.

Animal Gases

• Gas exchange follows the a similar trend in animals, oxygen and carbon dioxide diffuses across moist membranes.
• Exchange happens directly in simple animals/complex organisms (mammals).
• The blood carries oxygen to embedded cells and carries carbon dioxide out of the body.
• Earthworms transfer oxygen and carbon dioxide directly through their skin: Oxygen diffuses mixes with hemoglobin (red pigment) that binds oxygen across the bloodstream.
• Arthropods set of openings on the surface (spiracles) lead into tiny air tubes (tracheae) into areas of arthropod body.
• Fishes use external extensions for gas exchange e.g., gills (tissue flaps with blood vessels).
• Water swims into fish mouth and through the gills: Oxygen spreads out from water through the gills' blood vessels, carbon dioxide exits and enters the water.
• Terrestrial vertebrates have lungs e.g., amphibians, reptiles, birds, mammals.
• Frogs breath air into lungs; Oxygen diffuses into the hemoglobin in red blood cells.
• Reptiles increase surface space for gas exchange via folded lungs plus rib muscles aide expansion and protect the lungs.
• Bird lungs have large air spaces (air sacs), Rib cage spreads, vacuums created and air flow created.
• Gas exchange occurs in air sacs- adaptation for flight/metabolism.
• Mammilian lungs are alveoli (millions of microscopic air sacs) surrounded by network of blood vessels for gas.
• Mammals have diaphragm (dome-shaped) separates the thorax / abdomen to create chest cavity for breathing/blood circulating.
• During inhalation diaphragm contracts and flattens to create a partial vacuum in the lungs so that air can follow.

Human Respiration

• Diaphragm muscles contract, which enables respiration.
• Oxygen is taken in when you breathe
• Gas exchange occurs at the molecular level in the alveoli (tiny sacs in lungs as essential/functional part).
• The alveolar epithelial tissue is extremely thin and permeable to facilitate gas exchange between air inside / bloodstream capillaries.
• Air moves due to pressure variations. Air flows from high-pressure to low-pressure areas.
• Respiratory system provides oxygen, extracts carbon dioxide, and helps acid-base balance.
• Sections of the respiratory system are also used for odor detection, voice generation, plus during child birth, coughing, and stress.

Complex structures for human respiratory

• The parts: Mouth and nose, sinuses, pharynx(throat), trachea(windpipe), bronchial tubes, lungs, diaphragm, ribs, alveoli, bronchioles, capillaries,lung lobes, pleura, cilia, epiglottis, larynx(voicebox)
• Mouth and Nose: openings to pull air.
• Sinuses: Hollow areas regulate humidity/temperature.
• Pharynx (throat): Tube to throat.
• Trachea: Connects throat to lungs.
• Bronchial tubes: Connect windpipe to each lung.
• Lungs: transfers oxygen.
• Diaphragm: helps lungs with pulling air and pushing air out.
• Ribs: bones that surround and protect lungs and heart.
• Alveoli: Tiny air sacs that exchange oxygen and carbon dioxide.
• Bronchioles: Small branches of the bronchial tubes.
• Capillaries: Blood vessels that move oxygen and carbon dioxide.
• Lung lobes: Sections of the lungs – three lobes in the right, two in the left.
• Pleura: sacs that separate lungs from the chest wall.
• Cilia: hairs to filter.
• Epiglottis: Tissue flap at esophagus.
• Larynx (voice box): Allows you to talk and make sounds when.

Human Respiration Process

• Body inhales via the nose and mouth.
• Before inhalation mucus/cilia trap dirt and germs.
• Diaphragm draws air into lungs.
• Alveoli facilitate the respitory and circulatory system meeting.
• Brain controls breathing & gas exchange is facilitated by simple diffusion.

Respiratory Structures

• Human: lungs
• Fish: gills
• Frog: lungs (skin+buccal cavity)
• Cockroach: Tracheae
• Earthworm: (mucus) skin

Transport/Circulation

• Multicellular organisms must be able to transport supplies (water, oxygen, and nutrients) to transport, so specialized transport mechanisms have developed.
• Transport needs vary in relation to surface area

Humans

• The human circulatory system: heart, blood vessels and blood.
• Oxygen travels to lungs to the body.
• Oxygen from cellular respiration travels bodies to lungs.
• Blood supplies cell with oxygen/nutrients & picks up waste.

Mineral Transport

• Plants use the active transport via Osmosis from root to stem.

Blood

• Blood not transported by blood around: sweat.
• Platelets main function: blood clots

Plant transport

• Supply raw materials for the photosynthesis to leaves + to different areas for use/storage.

Xylem Transport

• Water + Minerals up through stem in xylem vessels- hollowed-out pipers that lignified the structure.
• Water moves in xylem = physical process.

Phloem Transport

• Sugar from photosynthesis moves from leaves to all parts of plant tissue=Phloem transport.
• Transport of material in pholem= translocation
• Pholem composes of living things: Sieve tubes +companion cells.

Moving Water

• Plants transport water through multiple mechanisms to carry water and food.
• Heterotrophs cannot create feed so they depend on what others create for their existence.
• Root hair cells help absorption via osmosis.
• Xylem helps transport through tissues.

Animal Transpiration

• The blood consists of fluid parts + erthrocites + throbocytes.
• There are two circular systems for different organisms.
• Fish mostly use open circle systems to circulate blood.
• Systemic systems + Mammalian.

Heart-Organ

• Hearts are a pump that uses arteries + veins to circulate.
• In animals, closed circular systems are separated while on open systems they are both.
• The heart moves everything together.

Vessel System

• Resembles a tree + leads to cell system.

Pulmonary System

• Has two circulatory systems to provide best flow.

Systemic System

• All of circulation goes through heart + to rest of the system.

Oxygen & Plant Notes

• Gases exchange by traveling from high to low density.
• Stomata regulates in gas exchange with photosynthesis.
• Transpiration stream from roots -> shoots -> Leaves

Stroke

• Laryngitis is an inflammation to the Larynx while pharyngitis effects the Pharynx leading to difficulty breathing.
• Capilleries are the site of gas exchange while alveoli is the site where gas enters in the lungs.
• Artery transfers fluids with oxygen to bodys tissue. Hope this gets you the best results for the test!