Plants and Humans- Exam 2

Photosynthesis

How plants use sunlight to make their own food.

Carbon dioxide + water

Reactants in the photosynthesis process.

Glucose + oxygen

Products of the photosynthesis process.

Chlorophyll A

The main pigment for photosynthesis that uses light energy, carbon dioxide, and water to create glucose and oxygen.

Chlorophyll B

Primarily absorbs blue and red-orange light.

Carotenoids

Absorb blue and green light.

Chloroplasts

Double membraned organelles where photosynthesis occurs.

Granum

Stack of thylakoids found in chloroplasts.

Thylakoids

Quarter shaped disks found in chloroplasts.

Stroma

Fluid found inside the chloroplast.

Photosynthesis equation

6CO2 + 6H2O --> light energy --> C6H12O6 + 6O2.

Light Dependent Reaction

Converts light energy into chemical energy in the form of ATP and NADPH, using water and releasing oxygen as a byproduct.

Calvin Cycle/Light Independent Reaction

A series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose, using energy from ATP and NADPH produced during the light-dependent reactions.

Cellular Respiration

The process that releases energy by breaking down food molecules in the presence of oxygen to create ATP.

Ethylene

Responsible for fruit ripening.

Auxin

Responsible for cell elongation and apical dominance.

Abscisic acid

Protects plants from drought stress/stress responses.

Gibberellin

Regulates seed germination and enzymes in a plant are produced after the embryo secretes this hormone.

Cytokinin

Responsible for activating cell division.

Seed Germination

The process by which a seed develops into a new plant, starting with water uptake (imbibition) and activating metabolic enzymes, leading to root and shoot growth.

Morphogenic response

Change in development or quality in plant.

All-or-None response

Responds completely or not at all to a stimulus.

Tropic Response

Directional plant growth movements in response to environmental stimuli like light, gravity, or touch.

Dosage-Dependent Response

The response depends on the dose.

Phototropism

Growth in response to light.

Gravitropism (Geotropism)

Growth in response to gravity.

Etiolation

Differences in development when seedlings are grown in the dark.

Nastic Response

Plant responses to environmental stimuli where the direction of the movement is not determined by the direction of the stimulus.

Statoliths

Starch grains inside the statocyte

Statocytes

Groups of sensory cells that help determine the direction of gravity

Climacteric fruits

Fruits that ripen AFTER they have been harvested (bananas, tomatoes, apples)

Non-climacteric fruits

Fruits that are best ripened fully BEFORE being harvested

Sexual Reproduction

Genetically diverse reproduction; flowering plants reproduce sexually through a process called pollination

Asexual/Vegetative Propagation

NOT genetically diverse; parent plant sends out a runner along the ground which helps form new plants

Mitosis

Occurs in asexual reproduction (creating clones of DNA)

Interphase

The first stage of the cell cycle where the cell grows and copies its DNA

Cell Nuclear Division

The division of DNA in the nucleus

Cytokinesis

Division of the cytoplasm

Diploids

Cells with two complete sets of chromosomes

Haploid

Cells with one set of chromosomes

Sister chromatid

One half of a duplicated chromosome

Chromatin

Made up of DNA and proteins

Meiosis

A process that occurs in reproductive cells and is associated with sexual reproduction

Alternation of generations

Alternating life cycles of haploid (N) and diploid (2N)

Gametophyte

Haploid, or gamete-producing generation

Sporophyte

Diploid, or spore-producing generation

Double fertilization

A process leading to seed formation in Angiosperms, where one haploid sperm unites with a haploid egg to form a diploid zygote, and a second sperm unites with the two haploid central cell nuclei to produce triploid endosperm.

Prophase I

Homologous chromosomes pair up with each other; crossing over occurs

Metaphase I

Homologous chromosomes line up in the middle of the cell

Anaphase I

Homologous chromosomes are separated

Telophase I

Amount of DNA is halved

Prophase II

Nuclear envelope breaks down; spindles form; DNA forms visible x-shaped structures

Anaphase II

The DNA is separated

Telophase II

Chromosomes arrive at opposite poles; nuclei form, and the chromosome begins decondensing

Cytokinesis after Meiosis II

Ends up with 4 daughter cells with half the DNA we started with

Population

Individuals of the same species living in the same place at the same time

Population Genetics

the study of the frequency of alleles in a population

Gene pool

ALL of the alleles for an individual in the population. Factors that can change the gene pool include gene drift, artificial selection, natural selection

Gene drift

Random change in alleles, purely a random event, more likely in small populations

Artificial selection

selective breeding of plants and animals to promote the occurrence of desirable traits in offspring

Natural Selection

survival of the fittest

Variation

all members of the population CANNOT have the same alleles

Overproduction

more offspring is produced that can actually survive

Competition principle

limited resources in the environment

Survival to Reproduce

individuals are better adapted to the environment are more likely to reproduce and pass on that trait

Species

A group of organisms that can interbreed and produce fertile offspring

Speciation

The process of a new species development

Allopatric Speciation

Involves geographic separation. A mode of speciation where a population becomes geographically isolated, leading to the formation of new species due to the lack of gene flow between the separated groups

Sympatric Speciation

Involves the species remaining in the same place. The evolution of a new species from a surviving ancestral species, where both continue to inhabit the same geographic region without any physical barriers to gene flow.

Divergent Evolution

when two or more species sharing a common ancestor become more different over time. Ex: elephants and mammoths

Convergent Evolution

the independent evolution of similar features in different lineages. Ex: sharks and dolphins

Adaptive Radiation

evolution from a common ancestor of many species adapted to diverse environments. Ex: Darwin's finches

Taxonomy

the science of naming and classifying organisms

Order of taxonomy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Domain

3; bacteria, archaea and eukarya

Kingdom

6, Archaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia

Phylogenetic tree

A branching diagram that represents evolutionary relationships

Cladogram

Diagram that shows the development of characteristics

Cytokinesis

Splitting of the diploid gamete into two haploid daughter cells

Mitosis vs. meiosis

Mitosis is involved in growth and development of vegetative parts, producing two identical diploid cells, while meiosis is crucial for sexual reproduction, producing four haploid gametes with half the genetic material

Result of mitosis

Two genetically identical diploid cells

Result of meiosis

Four genetically unique haploid cells