Plant Reproduction and Development

• Flowers are reproductive shoots of angiosperms.
• The receptacle is the part of the stem where floral organs attach.

Plant Reproductive Organs

• Sepals enclose and protect the flower bud, usually green and leaflike.
• Petals are brighter than sepals, attracting insects and other pollinators.
• The stamen (male part) consists of the anther, which produces pollen, and the filament, a long stalk holding the anther.
• The pistil/carpel (female part) can be a single carpel or a group of fused carpels. includes the Ovary (contains ovules), Ovules (full of eggs), Style (connects stigma to ovary), and Stigma (sticky, pollen sticks to it).

Reproductive Variation

• Complete flowers are monoecious.
• Incomplete flowers are dioecious.
• Gynoecious flowers have only female parts (ovules).
• Dioecious flowers can be either female or male.
• Bisexual flowers have both male and female parts.
• Unisexual flowers have only either male or female parts, either staminate (male) or pistillate (female).

Asexual Reproduction

• Vegetative propagation is asexual reproduction where a new plant grows from a vegetative part of the parent plant.
• Spore formation is a type of asexual reproduction used by ferns that involves single-celled spores surrounded by a thick wall.

Steps of Sexual Reproduction

• Pollination occurs when pollen is picked up by a pollinator and dropped into the pistil of another flower.
• Fertilization occurs when the pollen enters the pistil and fertilizes the ovary.
• Seed formation occurs as the ovule becomes a seed and the ovary becomes the fruit.

Alternation of Generations

• Plants alternate between sporophyte and gametophyte stages.
• Sporophytes reproduce asexually by producing spores.
• Gametophytes reproduce sexually by producing gametes.

Animal Development

• A zygote is a fertilized egg with the potential to produce all cell types of an individual.
• Vertebrate zygotes have yolks that provide food for the developing embryo.
• Human zygotes do not have yolks.
• Cleavage involves rapid mitosis without growth, leading to many cells.

16-cell Stage

• This stage is when the embryo becomes a morula - a tiny cluster of cells.
• During cleavage, ciliary action and muscular contraction push the embryo against the uterine tube.
• By the time the embryo reaches the uterus (around the 5th day), it is in the morula stage.

The Blastocyst

• Cells arrange into a hollow ball called a blastocyst (blastula) after cleavage.
• Nutritive membranes form the chorion and placenta, surrounding to the chorion.
• A small cluster of cells (the inner cell mass), projects into the cavity of the blastocyst and produces the embryo.

Implantation

• Implantation occurs in the endometrium (lining) of the uterus, beginning on the seventh day of embryonic development.
• Enzymes break down maternal capillaries to provide nutrition.
• Implantation completes by the ninth day of development.

Formation of Germ Layers (Gastrulation)

• The inner cell mass arranges into a two-layered disk.
• Cells merge into the primitive gut, ultimately forming the digestive tract.
• Cells become the endoderm, while remaining cells form the ectoderm.
• The mesoderm proliferates between the ectoderm and endoderm.
• Ectoderm, mesoderm, and endoderm are the three germ layers that give rise to specific structures in vertebrate embryos.
• Ectoderm forms the nervous system, epidermis, and pituitary gland.
• Mesoderm forms the skeleton, muscles, circulatory, excretory, and reproductive systems, dermis, and digestive tube layers.
• Endoderm forms the digestive tube lining and related structures, like the respiratory system.

Stages in the Human Life Cycle

• Embryo: From conception to the end of the 8th week, a single-celled zygote develops into a 3mm long embryo.
• Fetus: From the 9th week to birth, rapid growth, morphogenesis, and cellular differentiation occur.
• Neonate: From birth to 4 weeks, vital physiological adjustments are made.
• Infant: From the end of 4 weeks to 2 years, deciduous teeth appear, the nervous system develops, and coordinated activities and language skills emerge.
• Child: From 2 years to puberty, permanent teeth grow, muscular coordination improves, and intellectual abilities develop.
• Adolescent: From puberty (11-14) to adulthood, primary and secondary sexual characteristics develop, motor skills improve, and psychological changes and adult responsibilities emerge.
• Young Adult: From 20 to 40 years, physical development peaks, and adult responsibilities are taken on. Middle Age: From 40 to 65 years, aging, menopause, and physical changes occur.
• Old Age: From 65 years until death, senescence occurs, homeostasis becomes difficult, and death results from cardiovascular or immune system failure.

Plant Development

• Plants capture sunlight and store it as food for later use by plants and animals.
• Tracheophytes are vascular plants.

Seeds

• Seed plants are classified as gymnosperms or angiosperms based on seed-bearing properties.

Gymnosperms

• Include conifers, cycads, ginkgo, and gnetophytes.
• Seeds are naked (unenclosed).

Angiosperms

• A large group including herbaceous plants, shrubs, grasses, and most trees.
• Subdivided into monocots and dicots.

Monocotyledon Seeds

• Seed is surrounded by a protective coat.
• The aleurone layer, under the seed coat, is a digestive organ for germination.
• The endosperm is food storage tissue, formed separately from the embryo.
• Coleorhiza protects the future root (radicle) as it grows.
• The only structures remaining after discarding are the radicle, mesocotyl (future stem), and shoot apex.

Dicotyledon Seeds

• Have two cotyledons.
• Cotyledons serve as food storage instead of the endosperm.
• Other structures include the radicle (root) and plumule (shoot apex).
• Nothing compares to structures like alevrone or coleorhiza in most dicot seeds. Some have a functional endosperm.

Embryo and Cotyledon

• A result of one of two distinct fertilizations:
• Endosperm (if any) is produced
• Second fertilization yields a zygote, which undergoes cleavage.
• Cell divisions first produce a basal cell, which develops into a suspensor.
• A terminal cell divides, forming a rounded mass which from this mass grows the two cotyledons and a central axis.
• In dicots, parts of the central axis are the hypocotyl (below cotyledon attachment point), and the epicotyl (above attachment point).
• The embryo is in a state of dormancy when the seed has reached this stage of development.

Seed Germination

• Embryonic plant kept in suspended development (dormancy).
• Dormancy ends when germination takes place.
• Embryo emits gibberellin hormone, diffusing through seed, breaking dormancy.
• Hormone triggers production of digestive enzymes by the aleurone (in monocots) or cotyledons (in dicots).
• Digestive enzymes break down stored food in endosperm or cotyledons.
• Amylase breaks down starch to form maltose, cleaved into glucose.
• Other enzymes mobilize stored proteins, fats, and oils.

Early Root Emergence

• Root tip has a cap of dead cells protecting tender tissues and acting as a source of growth hormone.
• Living tissue undergoes mitosis, making the root tip the zone of division; it is an apical meristem of differentiating tissue.
• Cells enlarge in the zone of elongation, contributing to lengthwise root growth.
• Older parts of elongation zone cease growth and incorporate into the zone of maturation, where tissue differentiation begins.

Primary Meristems

• These produce differentiated tissues like phloem and xylem.
• Some tissues remain undifferentiated to form cambium in the stem and pericycle in the root.
• These form differentiated tissues that allow for lateral growth and girth increase.

Leaf Growth

• Each leaf originates on meristem, grows upward, enlarges, and differentiates.
• Once growth is underway, another group of cells grows outward and upward.

Leaf Fall

• Leaves eventually die; some plants experience complete senscence.
• Xylem ages, clogs with resin, and becomes heartwood. Cells produced by cork cambium die and become cork.
• Deciduous trees intentionally kills leaves for water conservation in the cold.

Ecology of Abscission

• The process by which plants shed parts is called abscission.
• Abscission can be an adaptation, permitting leaf loss and creating weaknesses so yellowed leaves are blown off in winter winds.

Secondary Growth

• In dicots, differentiation occurs behind growing plant stem and root tips.
• Stems differentiate nearest the apical zone of mitosis.
• A cylinder in the center of the apical bud develops into the vascular tissues as it matures and is called the provascular cylinder.
• Potential epidermis located on the exterior is called the protoderm.
• Ground meristem or ground tissues lie between the two cylinders, which becomes the cortex and the pith
• Secondary growth doesn't frequently occur in monocots.

Monocot Tree Trunk

• Tree-like shape with constant diameter, even smaller at the base.
• Primary thickening meristem, as big as the trunk, produced from apical meristem keeps enlarging.
• Primary thickening meristem lays down vascular and other tissues to form palm stem.

Animal Reproduction

• Animals can reproduce asexually or sexually.

Asexual Reproduction

• Involves one parent creating a new individual
• It enables animals living in isolation to reproduce without needing a mate
• It can also create many offspring rapidly.

Advantages of Asexual Reproduction

• Most advantageous in stable, favorable environments because successful genotypes are perpetuated precisely.
• Fission is a mechanism that involves parent separating into two or more equal sized organisms. (e.g. sea anemone)
• Budding involves a bud growing and breaking off from the parent. (e.g. Cnidarians and tunicates)
• Fragmentation involves the body breaking into pieces, where each piece grows into a new organism. (e.g. Flatworms)
• Regeneration involves regrowing lost parts, or the the lost parts grow into a new animal. (e.g. Sea stars)

Sexual Reproduction

• Sexual reproduction increases genetic variability among offspring
• The creation of offspring occurs by the fusion of haploid gametes into a diploid zygote.
• Offspring have phenotypes suited to environmental factors.
• Sex combines two parents of whom contributes a specialized gamete (the egg or sperm).
• Each gamete forms a fertilized egg or zygote, which fuses.
• Internal fertilzation requires female moist tissue- sperm goes directly in.
• External fertilization is when mating partners release eggs and sperm together.

Reproductive Variations

• Metagenesis (AKA transformation development) alternates the asexual(polyps) and sexual(Medusa) generations.
• Parthenogenesis (AKA virgin development) is when an unfertilized egg develops into an adult animal.(e.g Honey bees)

Hermaphroditism

• A single organism produces both eggs and sperm.
• Reproduction is still sexual.
• Earthworms do not self fertilize.

Female Reproductive Anatomy

• Ovaries produce the egg cell and sex hormones, enclosed in a protective capsule and containing many follicles.
• Ovulation occurs when the egg cell is expelled from the follicle.
• Oviducts (fallopian tubes) and Uterus are where and egg cell is released into near oviduct
• The endometrium is the rich inner lining of the uterus
• The cervix is the uterus neck, opening into the vagina.
• Vagina and Vulva- Vaginas are thin-walled chambers and the repository to sperm.
• A vagina is a birth canal for babies
• The vulva is a collective name for external female genitalia
• Mammary Glands are present but in women. Although critical for mammalian production.

Male Reproductive Anatomy

• The testes contain coiled tubes where sperm is created (seminiferous tubules) surrounded by tissue.
• Leydig cells produce testosterone/androgen. sperm can't occur at normal body temperature so tests are outside of the abdomen. ,
• Semiferous tubules cause sperm to go to epididymis. Which transfers sperm through vas deferens during ejaculation. These run around the bladder and connect ejactulatory duct.
• The glands are seminal vesicles, prostate and bulbourethral
• Secrete secrets into the semen or ejaculate fluid
• Sperm count ranges from 50-130 mil per mL of semen
• Prostaglandins cause mucus thinning.
• Penis has 3 erectile cylinders. These can make the penis get errect or fill with blood

Intoduction to Genetics

• Nucleotide: the ogrenaic moelcule that bilds DNA and RNA
• COdon- Set od 3 ncueloties in DNA. Protein to a series

Genetics

Scientific studies of genes and heredity, or how variations in DNA sequence cause specific characteristics or traits to be passed from parents to offspring. Branch of Biology concerned with the DNA of organisms. The most basic unity of inheritance, composed of DNA molecules that are transferred from parents to their offspring.

Genes

• Passed down from parents to offspring and contain the information needed to specify physiological and biological traits.
• Part of our genome that encodes the information ,aking those codes for specific proteins or segments of proteins.

The human genome has roughly 20,000 protein-coding genes. Made up of DNA (Deoxyribonucleic acid). Genes >> DNA >> Chromosomes >> Nitrogenous Bases.

Deoxyribonucleic Acid (DNA)

• Located in the cell nucleus (Nuclear DNA).
• Information in DNA is stored as code made up of four chemical bases:
• Adenine (A), Guanine (G), Cytosine (C), Thymine (T).Nitrogenous base pairs: A and T and C and G.
• Each base is attached to a sugar molecule and a phosphate molecule.
• Each base pair is bonded through Hydrogen Bonds.
• The ratio of adenine is always equal to thymine and likewise for guanine and cytosine. The Backbone of DNA is composed of alternation deoxyribose sugar and phosphate.

Nucleotides

• A base, sugar, and phosphate; they are arranged in two long strands. The blue part in the image is the nucleotide.

Key terms for reference

• Allele: One more alternative forms of a gene.
• Dominant: a tarit that is expressed
• F1: Generation Firats genration od orpsing
• F2: product from 1 f1 generation.
• Gamete is the reproductiove sex cell. Genotype: Genetic compisition of an indvidiual.
• Heterozyyous -Organsims htat hav etwo difernt aleees fo rth eams trait ex, like an Tt
• Homozyyous - Orgnaisme thtat have idnicla aleees for partiluclar trut
• phenotype, charactiersicts of individuals

Basic Genetic Concepts

• Punnett Squares predict outcomes of breeding experiments.
• Recessive traits are masked by the presence of a dominant trait.
• Phenotype: observable traits; Genotype: combinations of alleles.
• Dominant traits are observable traits.
• Recessive traits are present but not observable.

History of Genetics

• Gregor Mendel is known as the Father of Genetics.
• Mendel Used pea plant and grew over 10K plants to keep track of the progeny.
• Why pea plants= They are easy to grow, Traits are easy to view, you can work on larege smaple of samples.

Characteristics of Observed Pea Plants

• Seed and color
• Flower position
• Stem length
• Pod shape and color

Mendelian Genetics

• Mendelian principles predict patterns of inheritance.
• Non-Mendelian genetics don't follow typical patterns.
• Organisms have two alleles for traits via sperm or egg-> the separate allele is taken.
• Both random; after each passes aleee to child, its only upon gean formtaion taht the sepatae alegge
• (Analogy: Imagine your parents giving you one sock each for a pair not both socks from the same parent!
• Law of Independent Assortment: Genes travel different on chmrsines thenthey influence one another on how they are sorted re- resembted.
• Law of Dominance: Dominant hides recesseie- tall is dominant.

Sex Linkages and Genetic Recombination

• Sex Linkages is when a gene is placed on the X or Y axis. males are likely to have more x linked tarits.
• DNA recombinaiton is material changes after meiosis- in the end
• A important factor during the repordutctive cycle is when a Dna switches with anotehr. You about 50% from eacdh pair

Color Blindness

A recessive hereditery disorder in which the affected persion cannot see all of their colors. the huams genes fo the the colr vision in the X protanipia id red deueratopia is grene

Pedigree chart

• Shows relationships b/wfam members.
• Indicates which individuals have pathogenic variants
• Can be used to determine disease inheritance
• Autsomal means both have and all are affected "If genes not given, it is usually.

Animal development

• Zygote is feterila.
• Blastocyst- innner turns embroyo. "Implatation 1:3 to 5 day to hppen by then baby attached ti uterus

Plant developments

90% of all organnisms area plants . plants sunlight. Planstem leafe and root

• Types gynasperm and agnosperm

Tyeps of Agniospems Monicots, energy from ouer . Dicotshave 1

1 seed starts when seed isnt acitve but when cndiation r right

Test your knowledge of plant reproduction, including flower structures, fertilization, vegetative propagation, and seed germination. Explore the roles of different flower types, spore function in ferns, and root tip structures. Understand monoecious and dioecious plant classifications.