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Botany Collective Mind Map (Genetics (Monohybrid Crosses image (Test…
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concepts
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if an environment is relatively stable during several life times it is advantageous to reproduce asexually :check:
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if environment is not stable, offspring can find themselves in conditions that they are poorly adapted to.
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with asexual reproduction, progeny are never more fit than the parent, but during sexual reproduction :star:
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during seed/fruit maturation, those embryos with severely mismatched genes abort and use no further resources
pollen from one plant can be blown or carried by pollinators to the flowers of hundreds of other plants and vice versa for receiving :checkered_flag:
sex cells are so small that many can be produced by a single plant and many new combinations can be tested inexpensively :black_flag:
sex cells of one plant combine with those of one or several others resulting in many new gene combinations :red_flag:
Asexual Reproduction 
fragmentation is when a large spreading or vining plant grows to several meters in length and individual parts become self-sufficient by establishing adventitious roots :black_flag:
if middle portion dies, ends become separated and act as individuals
modifications like the cacti in which branches are poorly attached and when broken, form roots and become independent :check:
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Inflorescences and Pollination
when smaller flowers are grouped into inflorescences, two types of arrangements occur
indeterminate inflorescences, lowermost or outermost flowers open first not limiting the growth potential
many species do not have a main axis, and elongated pedicels
determinate inflorescences which has a limited potential for growth. terminal flowers typically open first stunting growth :check:
positioning of flowers on an individual plant is important few species are only able to produce limited amount of flowers :!:
flower size can also effect amount of nectar stolen, flowers pollinated, predators etc.
reproductive success is measured in terms of the number of healthy, viable seedling that become established. :!:
small flowers with only a few ovules can group together and create an inflorescence, to give a collective visual :star:
production of the pedicel, recepticle, sepals, and petals can be thought of as packaging and advertising cost, large flowers have advantage :check:
Fruit Types and Seed Dispersal
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Classification of fruit types
when seed is digested, may find itself in a pile of fertilizer and are well adapted to the new microenvironment :<3:
seeds are not distributed at random but are moved though the environment to specific sites when eaten by animals
pomes differ as they develop form inferior ovaries and inner tissue is true fruit and outer is accessory, seeds protected by bitter inner core :pear:
grapes and tomatoes are examples of simple flesh fruits, coat provide some protection but have slippery seed coats :green_cross:
Animals carry fruit in a variety of ways, they can stick to fur, be eaten and digested, and crushed and opened by stepped on :check:
fruits and seeds carried by wind must be lights and often have wings or parachutes. usually dry :star:
beans and peas form from a single carpel that contains several seeds, but do not fuse seeds :red_flag:
one method of classifying fruits is whether the fruit is dry or fleshy. dry fruit is not typically eaten during seed distribution, fleshy is opposite :check:
simplest fruits are grasses, are caryopses
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Flower Structure and Cross-pollination
Wind pollinated Flowers
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wind pollinated plants have a distinct set of modifications is adaptive, attracting pollinators is unnecessary
wind pollinated individuals produce up to several thousand small flowers, creates huge surface area for the plant :checkered_flag:
sepals are usually reduced or absent, ovaries need no special protection, zygomorphy is not advantageous :!:
Ovary position
Ovary and ovules must be well protected from pollinators, flower must bring animal close in order to effect pollination :lock:
adaptations include long styles and stamen filaments, burying ovaries deep within flower provided further protection :check:
most common arrangement is which there is no fusion to the ovary occurs and ovary is above other flower parts is :warning:
intermediate, partially buried ovaries are half-inferior with perigynous flower parts :check:
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all flower organ primordia are initieated at the receptacle apex, primordia crowd together, stamens, petals, sepals fuse . :star:
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cross pollination
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if plant is isolated by distance or lack of pollinators, self pollination allows it to set seed and propagate its genes rather than lose them :check:
self pollination is pollination of a carpel by pollen form the same flower or another flower on the same plant :<3:
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with cross pollination, sperm cells and egg cells fro different plants unite, resulting in new combinations of genes :star: #
Animal- Pollinated Flowers
most animals and plants relationships are a battle, animals try to eat or lay eggs in plants and plants use chemicals to defend :warning:
mutations have helped plants defend themselves and also indicate to friendly animals to come and pollinate
in many species, flowers and pollinators have coevolved in such a way that the flowers are now also bilaterally symmetrical called zygomorphic :check:
insect-flower association began around 120 million years ago, neither insects or flowers were sophisticated :black_flag:
most flowers are radially symmetrical meaning they produce mirror images when cut longitudinal. these are called actinomorphic or regular :sunflower:
mutations in plants increased due to the random insertion of pollen by insects that did not recognize specific plants
many lines of insects and flowers underwent coevolution, flower becoming adapted for visitation by a specific insect :star:
this began to create specific mutations such as size, shape, color, nectar production etc.
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Sexual Reproduction
The plant life cycle
Diploid adults have sex organs that produce haploid sex cells called gametes either sperms or eggs by meiosis :star:
fertilized egg is called a zygote, and will grow into a new individual :check:
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life cycles are complex in plants, the trees, shrubs, and herbs are just one phase called the sporophyte phase or sporophyte generation :check:
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difference between gametes and spores is great, gametes can fuse with other gametes in a process called syngamy or fertilization :star:
plant spores are the opposite they cannot undergo syngamy but each undergoes mitosis and grows into new haploid plant called gametophyte :star:
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during sexual reproduction, sporophyte is reduced but does not produce new diploid plant like itself but rather a haploid plant :check:
is a tiny mass of cells with no roots, stems, leaves, or vascular tissue :check:
in all vascular plants, a haploid gametophyte does not even remotely resemble a diploid sporophyte.
a life cycle with two generations, sporophyte and gametophyte is said to be an alternation of generations. :star:
because gametophytes do not resemble sporophytes at all this is an alternation of heteromorphic generations :check:
Fertilization
syngamy of sperm and egg involves both plasmogamy, fusion of the protoplasts of the gametes and karyogamy fusion of nuclei :check:
as pollen tube grows downward through the style toward the ovule, its guided to the micropyle
sperm nucleus enters the egg, then is drawn to and fuses with the egg nucleus establishing a diploid zygote nucleus
it penetrates nucellus and reaches egg apparatus, entering one synergid. pollen tube tip bursts and releases both sperm cells
because sperm sheds its protoplasm as its passes through the synergid, its contributes only its nucleus during karyogamy :star:
sperm does not carry mitochondria or plastids into the egg, organellar genes from pollen parent are rarely inherited by zygote
mitochondria and plastid genes of the embryo are inherited only from the ovule parent, except in conifers :check:
Endosperm nucleus initiates a dynamic cytoplasm and the central cell enlarges enormously, usually without cell division :check:
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in angiosperms only, second sperm nucleus released from the pollen tube migrates from the synergid into the central cell :star:
undergoes karyogamy with both polar nuclei establishing a large endosperm nucleus that is triploid :red_flag:
both sperm nuclei undergo fusions, one with the egg nucleus and the other with the polar nuclei called double fertilization :star:
Flower structure
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Carpels
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ovules develops into a seed after its egg is fertilized and surrounding ovary develops into a fruit :green_apple:
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megaspores differ from microspores because ovules and carpel do not dehisce and the megaspore remains enclosed :red_flag:
inside every ovary are placentae, regions of tissue that bear small structures calles ovules :star:
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ovules have short stalk, called funicules and have a central mass of parenchyma called nucellus :check:
sepals
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protect flower bud as they develop and maintain high humidity and protect plant from nectar robbing insects and birds :star:
are modified leaves that enclose other flower parts when they mature, are typically thickest, toughest of the flower parts
stamens
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located above the petals and collectively known as the androecium, incorrectly referred to as male part, produces pollen :check:
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have two parts
anther is composed of diploid cells and in each anther, 4 long columns of tissue become distinct as cells enlarge and undergo meiosis :recycle:
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neighboring anther cells, in a layer called the tapetum act as nurse cells, contributing to microspore development
Microspore mother cells or microsprocytes continue to enlarge then undergo meiosis each producing 4 microspores. :<3:
petals
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attract correct pollinators due to shape, color, and orientation
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are leaf like as they are broad but contain pigments other than chlorophyll, have fewer to no fibers and tend to be thinner :check:
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Fruit Development
as the ovule develops into a seed, the ovary matures into a fruit. Development varies with the nature of the carpels as well as nature of the fruit :check:
3 layers become distinct
exocarp is the outer layer, the skin or peel
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the entire fruit wall, whether composed of 1,2, or all 3 layers is the pericarp :star:
Gametophytes
Megagametophyte
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within the ovule, surviving megaspore develops into a megagametophyte :check:
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Microgametophyte
microspores develop into microgametophytes, each microgametophyte is very small and simple :star:
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microspore nucleus migrates to the side of the pollen grain and lies next to the wall and divides mitotically
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after pollen grain lands on a stigma, it germinates by producing a pollen tube that penetrates into the loose, open tissues of the stigma :check:
30% of angosperm species formation of sperm cells occurs even while pollen is still located withing the anther :black_flag:
Embryo and seed development #
a mature seed in which endosperm is rather abundant is an albuminous seed. If endosperm is sparse or absent, seed is exalbuminous :star:
amount of embryo growth and development that occurs before dormancy sets in is extremely variable :warning:
the integuments that surround the nucellus expand and mature into the seed coat also called the testa and the rest of ovule grows
the embryo and endosperm develop from the zygote and megagametophyte central cell, both located in the nucellus of the ovule :check:
in most basal angiosperms, cotyledons store nutrients used during and after germination, become thick during embryo development :check:
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when seed is mature, cotyledons are large and the endosperm may be completely used up
later in the torpedo stage the embryo is and elongate cylinder, short axis is established consisting of radicle(embryonic root) :red_flag:
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The end of the embryo farther form the suspensor initiates 2 primordia that grows into 2 cotyledons in basal angiosperms :star:
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as the endosperm nucleus proliferates, zygote also begins to grow, always by nuclear and cellular divisions
cells at one end of the sspensor continue to divide mitotically, developing into an embryo.
the zygote grows into small cluster of cells which later become a short stalk-like structure called the suspensor which pushes the embryo deep into the endosperm :check:
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Nonvascular Plants: Mosses, Liverworts, and Hornworts
Division Anthocerotophyta: Hornworts
hornworts are a group of small, inconspicuous thalloid plants that grow on moist soil hidden by grasses and herbs :star:
hornworts are quite distinct from other embryophytes as they have a large chloroplast in each cell :red_flag:
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rarely inhabit tree trunks or bare rock, must be looking for them specifically : :recycle:
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species names are synonyms as there can be many names for one species because of the variability of growth :check:
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Division Bryophyia: Mosses
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metabolism and ecology
small size and lack of conducting tissues are critical factors in metabolism and ecology of mosses :star:
are important in the later establishment of other species like vascular plants. will happen in almost all environments :check:
larger vascualr plants adapted to survive dry spells will moss gametophores are not, have mechanisms to compensate :check:
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tolerant of desiccation, these can be resistant to high and low temperatures and intense UV light :warning:
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Classification of Nonvascular plants
not know how closely related mosses, liverworts or hornworts are :star:
use to be all classified in Bryophyta with mosses= Musci, liverworts=Hapaticae, hornworts= Anthocerotae
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Division Hepatophyta: Liverworts
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Concepts
plants are divided into :star: #
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as plants became better at surviving on land, competition for sunlight became important in areas near water :star:
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as evolution continued, more tissues are added and allowed grow more essential items such as roots
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green algae known as charophytes began adapting to live on land 450 million years ago. :first_place_medal:
adaptations possibly allowed the algae to be metabolically active during times of drought or extreme conditions :check:
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adapted a large, compact multi-cellular body with low surface to volume ratio. :black_flag:
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