Evolution Flashcards
What is the starting point of reproduction according to cell theory?
All living organisms are composed of one or more cells which originate from pre-existing cells by the process of cell division.
What are the main reasons for cell division?
- Growth
- Repair of old/dead cells
- Reproduction
What is reproduction?
The process by which living organisms produce offspring of their own kind.
What are the two types of reproduction?
- Asexual (involves only one parent)
- Sexual (involves a combination of two parents)
What processes are involved in asexual reproduction?
Mitosis and cytokinesis.
What does mitosis accomplish?
The nucleus divides into two nuclei with identical genetic material.
List the importance of mitosis.
- Growth & development
- Asexual reproduction in some organisms
- Cell repair & replacement
- Copying & transfer of next generation nuclei/cells
- Maintaining the regular number of chromosomes in somatic cells
What is cytokinesis?
The process that completes cell division, separating the cytoplasm and organelles into two new daughter cells.
What are the two main parts of the cell cycle?
- Interphase
- Mitosis
What is interphase?
The preparatory stage that lasts from the end of one cell division to the beginning of the next.
What percentage of the cell cycle does interphase occupy?
About 90% of the time.
What occurs during the G1 phase of interphase?
The cell grows and prepares to replicate its DNA.
What happens during the S phase of interphase?
The chromosomes replicate, resulting in two identical copies called sister chromatids.
What occurs during the G2 phase of interphase?
Organelles and materials required for cell division are formed or replicated.
What are the five main phases of mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
What happens during prophase?
Sister chromatids become visible and the nuclear envelope breaks up.
What occurs during prometaphase?
Chromosomes gradually migrate to the center of the cell.
What is the arrangement of chromosomes during metaphase?
Chromosomes are lined up along the equatorial plate.
What happens during anaphase?
Centromeres are pulled apart, causing sister chromatids to separate into two daughter chromosomes.
What marks the beginning of telophase?
Separated chromosomes reach the opposite poles of the cell.
What is the final stage of the cell cycle?
Cytokinesis.
How does cytokinesis differ in animal and plant cells?
- Animal cells: cleavage furrow forms and deepens.
- Plant cells: a cell plate forms to divide the cell.
What happens to cells that do not divide in adult animals?
They exit G1 phase to enter an inactive stage called the quiescent stage (G0).
What happens to cells in this stage?
Cells remain metabolically active but no longer proliferate unless called upon to do so depending on the requirement of the organism.
What is asexual reproduction?
Reproduction that occurs without the fusion of gametes, resulting in offspring that are genetically identical to the parent.
What is binary fission?
The simplest form of asexual reproduction where the parent cell divides into two equal daughter cells.
In which organisms does binary fission occur?
Unicellular organisms such as bacteria, algae, amoeba, and paramecium.
What is budding?
A form of asexual reproduction resulting in the formation of two unequal parts, where a smaller version of the parent detaches to become self-sufficient.
Which organisms reproduce by budding?
Hydra, yeast, sea sponge, and corals.
What is spore formation?
The production of specialized cells capable of germinating into new individuals identical to their parents.
How do spores differ from seeds?
Spores are produced by the division of cells on the parent, not by the union of two cells.
Examples of organisms that reproduce by spores include:
- Fungi
- Green algae
- Ferns
What is vegetative reproduction?
A type of asexual reproduction in plants where offspring are produced from vegetative structures like roots, stems, and leaves.
What are the two types of vegetative reproduction?
- Natural vegetative reproduction
- Artificial vegetative reproduction
What methods are used in natural vegetative reproduction?
- Bulbs
- Corms
- Tubers
- Runners
- Rhizomes
Examples of plants that undergo natural vegetative reproduction include:
- Onions
- Tulips
- Lilies
- Gladioli
- Potatoes
- Strawberries
- Ginger
What is cutting in artificial vegetative reproduction?
Using a vegetative structure to create a new individual by cutting, treating with growth hormones, and planting.
What is layering in artificial vegetative reproduction?
Bending a stem over and covering it with soil to form a new plant, which is then cut from the parent.
What is grafting?
A technique where a stem or bud is cut from one plant and joined to another closely related plant.
In grafting, what are the terms for the root-producing part and the added piece?
- Stock (root-producing part)
- Scion (added piece)
What is regeneration?
The ability of an organism to regrow lost body parts.
Examples of organisms capable of regeneration include:
- Starfish
- Earthworms
- Hydras
- Planarians
What is parthenogenesis?
A form of asexual reproduction where a zygote is produced from an unfertilized egg.
In which organisms does parthenogenesis occur?
- Invertebrates (e.g., scorpions, nematodes, mites)
- Some vertebrates (e.g., amphibians, fish, reptiles, birds)
Which species of sharks have been observed to reproduce via parthenogenesis?
- Blacktip shark
- Bonnethead shark
- Zebra shark
True or False: Parthenogenesis can occur in both animals and plants.
True
Parthenogenesis is also referred to as _______.
[virgin birth]
What are the two types of parthenogenesis?
Automixis parthenogenesis and apomixis parthenogenesis
Automixis involves the fusion of the egg cell with the polar body, while apomixis does not involve meiotic division.
In automixis parthenogenesis, what is the result of the egg cell fusing with the polar body?
An embryo with genes similar to the mother but not a full clone
This process can lead to the production of new alleles.
What type of offspring does automixis parthenogenesis produce?
Female offspring only
Rarely, it can produce fertile males with only one X chromosome.
What is the key characteristic of offspring produced by apomixis parthenogenesis?
They are full clones of the mother
This type is most commonly found in plants.
What is sexual reproduction?
A biological process that creates a new organism by combining the genetic material of two organisms
This process starts with meiosis.
What is the purpose of meiosis?
To ensure continuity & survival of organisms, increase genetic variation, and form gametes
It is also known as reduction division.
Where does meiosis occur in animals?
In the testis and ovaries
In plants, meiosis occurs in the anther and ovule.
What happens during interphase of germ cells?
The cell grows and diploid chromosomes replicate
This brings the total number of individual chromosomes (chromatid) to 92.
How many daughter cells are produced after meiosis I?
Two daughter cells
This occurs at telophase 1.
How many daughter cells are produced after meiosis II?
Four daughter cells
They have a haploid number of chromosomes.
What are gametes?
Specialized sex cells produced for sexual reproduction
They are formed by the combination of genetic material from two parent organisms.
What are the two types of gametes in anisogamous species?
Sperm (male) and ova (female)
Anisogamous species have different types of gametes.
In isogamous species, how do gametes differ?
They are similar or identical in form but may have separable properties
Examples include the green alga, Chlamydomonas reinhardtii.
At what age does puberty generally occur in females?
11 - 15 years
Influenced by factors such as nutrition and economic status.
At what age does puberty generally occur in males?
13 - 14 years
Influenced by similar factors as for females.
What are secondary sexual characteristics in males induced by?
Testosterone
Examples include a deeper voice and increased size of testes.
What is the function of the penis?
To deliver semen into the vagina during sexual intercourse
The urethra passes through the penis and allows urine and semen to exit the body.
What is the role of the scrotum?
To maintain the proper temperature of the testes
Sperm is destroyed unless a temperature of 34°C is maintained.
Where are gametes typically produced?
In gonads (ovaries & testes)
Germ cells are set aside early in development to produce only gametes.
What is gametogenesis?
The production of gametes
Includes spermatogenesis and oogenesis
What is spermatogenesis?
Each primary spermatocyte divides to form 4 sperm
Involves meiotic divisions
What is oogenesis?
Each primary oocyte divides to form 1 ovum and 2-3 polar bodies
Cytokinesis is unequal in oogenesis
What happens to polar bodies in oogenesis?
They degenerate
Polar bodies receive minimal cytoplasm
What are spermatogonia?
Diploid cells in the outermost layer of the seminiferous tubules
They develop into primary spermatocytes
What are secondary spermatocytes?
Cells formed after the first meiotic division of primary spermatocytes
They are haploid
What are spermatids?
Haploid cells formed when meiosis is complete
They mature into sperm
What is the vagina?
A tube leading from the uterus to the outside of the body
Also known as the birth canal
What is the cervix?
The lower portion of the uterus where the vagina and uterus meet
Plays a role in childbirth
What is the uterus?
A hollow, fist-sized organ located between the bladder and rectum
Responsible for nurturing the developing fetus
What are the fallopian tubes?
Two tubes connecting the uterus with the ovaries
Also called oviducts
What is the clitoris?
A small sensitive protrusion comparable to the penis in males
It can become erect and is very sensitive to stimulation
What is the usual pH of the vaginal environment?
Usually acidic
Can change due to medications, douches, or infections
What are the ovaries responsible for?
Production and release of eggs (ova)
Females are born with all the eggs they will ever produce
What is ovulation?
The release of ova from the ovaries
Occurs monthly
What is a simplex uterus?
Normal uterine structure
Abnormal forms include bicornuate or septate uterus
What are the two parts of the female reproductive cycle?
Uterine (menstrual) cycle and ovarian cycle
These cycles are integrated
What happens during the follicular phase of the ovarian cycle?
The maturing follicle develops an internal fluid-filled cavity and grows large
Ends with ovulation
What is the corpus luteum?
The structure formed from the follicle after ovulation
Secretes estrogen and progesterone
What happens during the luteal phase?
The corpus luteum secretes estrogen and progesterone
Inhibits GnRH production in the hypothalamus
What triggers menstruation if the egg is not fertilized?
The disintegration of the corpus luteum and a drop in estrogen and progesterone
Leads to breakdown of the endometrium
What is menstruation?
The flow of blood and lining from the inside of the uterus
Typically lasts 3-7 days
Fill in the blank: The follicular phase of the ovarian cycle is coordinated with the ______ phase of the uterine cycle.
proliferative
Both phases occur simultaneously
True or False: The uterine cycle typically lasts 28 days.
True
One cycle is from the beginning of one period to the next
What is gametogenesis?
The production of gametes
Includes spermatogenesis and oogenesis
What is spermatogenesis?
Each primary spermatocyte divides to form 4 sperm
Involves meiotic divisions
What is oogenesis?
Each primary oocyte divides to form 1 ovum and 2-3 polar bodies
Cytokinesis is unequal in oogenesis
What happens to polar bodies in oogenesis?
They degenerate
Polar bodies receive minimal cytoplasm
What are spermatogonia?
Diploid cells in the outermost layer of the seminiferous tubules
They develop into primary spermatocytes
What are secondary spermatocytes?
Cells formed after the first meiotic division of primary spermatocytes
They are haploid
What are spermatids?
Haploid cells formed when meiosis is complete
They mature into sperm
What is the vagina?
A tube leading from the uterus to the outside of the body
Also known as the birth canal
What is the cervix?
The lower portion of the uterus where the vagina and uterus meet
Plays a role in childbirth
What is the uterus?
A hollow, fist-sized organ located between the bladder and rectum
Responsible for nurturing the developing fetus
What are the fallopian tubes?
Two tubes connecting the uterus with the ovaries
Also called oviducts
What is the clitoris?
A small sensitive protrusion comparable to the penis in males
It can become erect and is very sensitive to stimulation
What is the usual pH of the vaginal environment?
Usually acidic
Can change due to medications, douches, or infections
What are the ovaries responsible for?
Production and release of eggs (ova)
Females are born with all the eggs they will ever produce
What is ovulation?
The release of ova from the ovaries
Occurs monthly
What is a simplex uterus?
Normal uterine structure
Abnormal forms include bicornuate or septate uterus
What are the two parts of the female reproductive cycle?
Uterine (menstrual) cycle and ovarian cycle
These cycles are integrated
What happens during the follicular phase of the ovarian cycle?
The maturing follicle develops an internal fluid-filled cavity and grows large
Ends with ovulation
What is the corpus luteum?
The structure formed from the follicle after ovulation
Secretes estrogen and progesterone
What happens during the luteal phase?
The corpus luteum secretes estrogen and progesterone
Inhibits GnRH production in the hypothalamus
What triggers menstruation if the egg is not fertilized?
The disintegration of the corpus luteum and a drop in estrogen and progesterone
Leads to breakdown of the endometrium
What is menstruation?
The flow of blood and lining from the inside of the uterus
Typically lasts 3-7 days
Fill in the blank: The follicular phase of the ovarian cycle is coordinated with the ______ phase of the uterine cycle.
proliferative
Both phases occur simultaneously
True or False: The uterine cycle typically lasts 28 days.
True
One cycle is from the beginning of one period to the next
What is the Law of Dominance?
When two unlike unit factors responsible for a single trait are present in a single individual, one unit factor is dominant to the other, which is said to be recessive.
What does Mendel’s first law of inheritance state?
An organism’s genetic makeup is called its genotype.
Define phenotype.
The physical trait an organism develops as a result of its genotypes.
What does Mendel’s law of segregation state?
The two alleles for a trait separate during gamete formation and end up in different gametes.
What ratio is typically produced in the F2 generation from a monohybrid cross?
3:1
What does Mendel’s law of independent assortment state?
During gamete formation, the segregating alleles assort independently of each other.
What ratio is typically produced in the F2 generation from a dihybrid cross?
9:3:3:1
What is a monohybrid?
An individual that is heterozygous for one trait.
What is a Punnett Square?
A diagram that can be used to show and predict genotype, phenotype, and probability ratios in a genetic cross.
Fill in the blank: A cross of two heterozygous tall plants (Tt) will produce: F2 - ____.
3 tall: 1 short plant(s)
What is codominance?
Both alleles are equally expressed and affect the phenotype.
Provide an example of codominance.
Roan cattle, where a cross between a red bull and a white cow yields roan calves.
What is the characteristic ratio for codominance?
1:2:1
What are the genotypes for homozygous red coat and white coat in roan cattle?
CR CR for red coat; CW CW for white coat.
What is incomplete dominance?
A blend of both alleles resulting in a phenotype that is intermediate between the two parental phenotypes.
Give an example of incomplete dominance.
Flower color in snapdragons, where a cross between white and red flowers produces pink offspring.
What is the characteristic ratio for incomplete dominance in the F2 generation?
1:2:1
What are multiple alleles?
Traits controlled by genes for which more than two alleles exist.
Provide an example of a trait controlled by multiple alleles.
The human ABO blood group system, controlled by alleles A, B, and O.
True or False: Even if more than two alleles exist in a population, each individual possesses more than two alleles.
False
What is the Law of Dominance?
When two unlike unit factors responsible for a single trait are present in a single individual, one unit factor is dominant to the other, which is said to be recessive.
What does Mendel’s first law of inheritance state?
An organism’s genetic makeup is called its genotype.
Define phenotype.
The physical trait an organism develops as a result of its genotypes.
What does Mendel’s law of segregation state?
The two alleles for a trait separate during gamete formation and end up in different gametes.
What ratio is typically produced in the F2 generation from a monohybrid cross?
3:1
What does Mendel’s law of independent assortment state?
During gamete formation, the segregating alleles assort independently of each other.
What ratio is typically produced in the F2 generation from a dihybrid cross?
9:3:3:1
What is a monohybrid?
An individual that is heterozygous for one trait.
What is a Punnett Square?
A diagram that can be used to show and predict genotype, phenotype, and probability ratios in a genetic cross.
Fill in the blank: A cross of two heterozygous tall plants (Tt) will produce: F2 - ____.
3 tall: 1 short plant(s)
What is codominance?
Both alleles are equally expressed and affect the phenotype.
Provide an example of codominance.
Roan cattle, where a cross between a red bull and a white cow yields roan calves.
What is the characteristic ratio for codominance?
1:2:1
What are the genotypes for homozygous red coat and white coat in roan cattle?
CR CR for red coat; CW CW for white coat.
What is incomplete dominance?
A blend of both alleles resulting in a phenotype that is intermediate between the two parental phenotypes.
Give an example of incomplete dominance.
Flower color in snapdragons, where a cross between white and red flowers produces pink offspring.
What is the characteristic ratio for incomplete dominance in the F2 generation?
1:2:1
What are multiple alleles?
Traits controlled by genes for which more than two alleles exist.
Provide an example of a trait controlled by multiple alleles.
The human ABO blood group system, controlled by alleles A, B, and O.
True or False: Even if more than two alleles exist in a population, each individual possesses more than two alleles.
False
What is evolution?
A gradual change over time.
Evolution encompasses geologic evolution and organic evolution.
What is geologic evolution?
Continuous changes of the Earth since its formation about 4.6 billion years ago.
What is organic evolution?
The evolution of organisms through gradual changes over time.
What is the main evidence for evolution?
Fossils, anatomical similarities, embryological similarities, and biochemical similarities.
What are the two types of fossil dating?
Relative dating and absolute dating.
What is relative dating?
A method that determines the order of events by observing sedimentary layers.
What is absolute dating?
A method that determines the actual time of events, such as radioactive dating.
What is the most reliable method of absolute dating?
Radioactive dating.
What is the half-life of Carbon-14?
About 5,730 years.
What happens to Carbon-14 after 50,000 years?
The amount remaining becomes too small to measure reliably.
Which isotopes can be used to date older fossils?
- Uranium-238 (half-life of about 4.46 billion years)
- Potassium-40 (half-life of about 1.28 billion years)
What can radioactive dating of sedimentary rocks determine?
The age of sediments, not the actual time the rock was formed.
What are some important facts revealed by fossil dating?
- Similar patterns of evolution
- Extinction of some species
- Missing links in fossil records
What does comparative anatomy study?
Structural similarities and differences among living things.
What are homologous structures?
Parts of different organisms with similar internal structures but different external forms and functions.
What are analogous structures?
Structures with similar external forms and functions but different internal structures.
What do embryological similarities provide evidence for?
Evolutionary relationships among species.
What do DNA analyses reveal about evolutionary relationships?
Closer phylogenetic relationships result in more identical DNA and protein structures.
Who was Anaximander and what was his contribution to evolution?
A Greek philosopher who suggested life began as slime in oceans and evolved over time.
What did Aristotle contribute to evolutionary thought?
Developed an epigenetic model of evolution and a classification system for animals.
What is John Ray known for?
Catalogued 18,600 kinds of plants and defined species based on common descent.
What is Carolus Linnaeus famous for?
Published ‘Systema Naturae’ and developed a classification system still in use today.
What did Erasmus Darwin propose in ‘Zoonomia’?
All life evolved from a common ancestor, driven by competition and sexual selection.
What is abiogenesis?
The hypothesis of spontaneous generation, disproved by experiments from Francesco Redi and Louis Pasteur.
Who proposed the first theory of evolution?
Jean Baptiste de Lamarck
What are the two principles of Lamarck’s theory of evolution?
- Law of use and disuse
- Inheritance of acquired characteristics
What does the law of use and disuse state?
The more an animal uses a part of its body, the stronger and better developed that part becomes, and vice versa
What is meant by inheritance of acquired characteristics?
Characteristics developed through use and disuse can be passed on to offspring
True or False: Lamarck’s theory has been proven correct in its basic premises.
False
What did George Cuvier maintain regarding species?
He maintained the ‘fixity’ of species
What is catastrophism according to Cuvier?
The theory that violent and sudden natural catastrophes cause extinctions and changes in species
How did Charles Lyell’s theory of uniformism differ from Cuvier’s catastrophism?
Lyell believed in slower, progressive changes rather than sudden catastrophes
What are the six main points of Darwin’s theory of evolution?
- Over-production
- Competition
- Variation
- Adaptations
- Natural Selection
- Speciation
What is natural selection?
The environment selects optimal traits to be the parents of the next generation
What is speciation?
The formation of new species through accumulation of favorable traits over generations
What is biogenesis?
The modern hypothesis that living organisms originate from pre-existing organisms
What is the primordial soup?
A hot, thin soup of water and organic materials covering early Earth
What type of cells are theorized to have evolved through endosymbiosis?
Eukaryotic cells
What is the synthetic theory of evolution?
A fusion of Darwin’s theory with modern discoveries in genetics and population theory
What is mutation?
A sudden change in the structure or amount of genetic material
Fill in the blank: Genetic recombination is the formation of new combinations of alleles during _______ reproduction.
sexual
What is genetic drift?
A change in the gene pool of a small population brought about by chance
What is an adaptation?
An inherited trait that improves the chances of survival and reproduction for an organism
True or False: Genetic drift is more likely to occur in large populations.
False
What are the three types of adaptations?
- Structural
- Physiological
- Behavioral
Structural adaptations involve physical modification, physiological adaptations pertain to metabolic processes, and behavioral adaptations are responses to environmental stimuli.
Define structural adaptation.
Adaptations that involve the modification of the body of the organism, e.g., the wings of birds and insects adapted for flight.
Structural adaptations are crucial for survival in specific environments.
What is physiological adaptation?
Involves the metabolism of organisms, e.g., the production of venom by snakes.
Physiological adaptations enhance an organism’s ability to survive and reproduce.
What is behavioral adaptation?
Particular responses made by an organism in any situation, e.g., migration of birds due to seasonal weather changes.
Behavioral adaptations can include mating behaviors and responses to predators.
What are the three general types of color adaptation?
- Protective coloration
- Warning coloration
- Mimicry
Color adaptations help organisms survive by either blending in with their environment or signaling danger.
Define protective coloration.
Enables an animal to blend in with its background, making it less likely to be seen by enemies.
Examples include the chameleon and sundial flounder.
What is warning coloration?
Occurs in certain poisonous or unpleasant-tasting animals, helping predators recognize them.
An example is the monarch butterfly, which birds avoid due to its distinctive coloring.
What is mimicry in the context of color adaptation?
Common in defenseless animals, mimics a closely related animal that possesses qualities that cause predators to avoid it.
The viceroy butterfly mimics the monarch butterfly to avoid predation.
What is directional selection?
A type of natural selection that favors a relatively rare phenotype, usually occurring when the environment changes.
An example is the evolution of long-necked giraffes.
Define stabilizing selection.
Favors the average phenotypes and limits evolution by keeping allele frequencies relatively constant.
This type of selection is common in stable environments.
What is disruptive selection?
Favors two rare and opposite phenotypes while acting against average phenotypes, resulting in the creation of two subpopulations.
This type of selection can lead to speciation.
What is speciation?
The formation of new species as a result of a net accumulation of favorable traits and adaptations.
Speciation often occurs due to geographic and reproductive isolation.
What is geographic isolation?
Occurs when a population is separated by a natural barrier, preventing interbreeding.
Barriers can include mountains, deserts, or bodies of water.
What does the term ‘range’ refer to in ecology?
The particular region of the earth where a species is found.
Species characteristics may vary across different parts of their range due to environmental conditions.
Define reproductive isolation.
The loss of the ability to interbreed by two isolated groups over time.
This can occur due to changes in courtship behaviors and mating times.
Fill in the blank: Reproductive isolation occurs when isolated groups can no longer _______.
interbreed.
This leads to the evolution of different gene pools in each group.
What is peripatric speciation?
A special form of allopatric speciation where a very small subpopulation becomes isolated from a much larger majority.
It is characterized by rapid divergence due to the founder effect and genetic drift.
What is the founder effect?
A phenomenon where small populations are more sensitive to genetic drift and natural selection acts on a small gene pool.
This effect can lead to rapid divergence in isolated populations.
Define sympatric speciation.
The formation of two or more descendant species from a single ancestral species all occupying the same geographic location.
It occurs through reproductive isolation and adaptation via genetic drift and natural selection.
What is polyploidy?
A condition in which an offspring or group of offspring is produced with twice the normal number of chromosomes.
Polyploidy is a common mechanism in sympatric speciation.
What is parapatric speciation?
An extremely rare type of speciation occurring when populations are separated by different niches in a habitat, rather than a geographic barrier.
Isolation may result from temporal or behavioral differences.
What is convergent evolution?
Evolution that results in the resemblance of unrelated species living in the same geographic location due to natural selection.
It leads to similar adaptive traits or analogous structures.
What is divergent evolution?
Evolution that results in the accumulation of differences between groups of the same species geographically isolated from each other.
It can lead to the formation of new species due to different selective pressures.
What is coevolution?
The evolution of two or more species simultaneously due to cooperative or competitive adaptations.
An example is the relationship between flowers and their pollinators.
What is artificial selection?
Evolution brought about by the selective actions of humans on plants and animals.
It favors individuals with certain traits, allowing them to reproduce and pass on their genes.
True or False: Artificial selection has provided strong evidence that selection is an effective evolutionary mechanism.
True
It has produced substantial change in almost every case it has been applied.
What is Industrial Melanism?
The evolutionary process in which darker individuals predominate over lighter individuals in populations exposed to industrial air pollution
Example: dominance of dark colored moths in industrialized England
What is the role of darker coloration in moths due to Industrial Melanism?
It serves as protective coloration to protect from predators
What is the interrelationship of living organisms?
All living organisms interact and are interdependent on each other and their environment for survival, reproduction, and ecological balance
What is an ecosystem?
An area where all biotic and abiotic parts interact
What are the categories of organism associations?
Interspecific and intraspecific categories
What is Saprotropism?
A type of relationship where living organisms grow on dead organic matter and take nutrients from it
What is saprophytic nutrition?
Nutrition found in non-green plants that draw nourishment from dead matter
What are the two types of saprophytes?
- Total saprophytes
- Partial saprophytes
What are total saprophytic organisms?
Organisms like fungi that completely depend on dead and decaying substances for nutrition
Example: Mucor, Agaricus
What is Antagonism in organism relationships?
A relationship where either one or both types of organisms are harmed
What is Parasitism?
A relationship where one organism (parasite) benefits at the expense of another (host)
What is an ectoparasite?
A parasite that lives outside the host body
What is an endoparasite?
A parasite that lives inside the host body
Give an example of an ectoparasite and an endoparasite.
- Ectoparasite: Lice
- Endoparasite: Round worm
What is Exploitation in organism relationships?
A relationship where one organism enslaves another
What is Ammensalism (antibiosis)?
A relationship where the chemical secretion of one organism harms another, with no nutrition taking place
What is an example of an antibiotic?
Penicillin, produced from the fungus Penicillium notatum
What is Competition in ecological relationships?
A relationship where two organisms compete for food and shelter
What is Symbiosis?
A relationship where living organisms live together and help one another
What are the three categories of Symbiosis?
- Commensalism
- Mutualism
- Protocooperation
What is Commensalism?
A relationship where one organism benefits and the other remains neutral, with no harm done
Give an example of Commensalism.
Fierasfer fish living inside the cloacal cavity of a Sea cucumber
What is Mutualism?
An obligatory relationship where both organisms benefit and are interdependent
Give an example of a mutualistic relationship.
The association between algae Zoochlorella and hydra
What is Protocooperation?
A facultative relationship where both organisms benefit but can live independently
Give an example of Protocooperation.
The association between hermit crab and sea anemone
What are the geographical locations of Tropical Savanna?
Large parts of eastern Africa, southern Brazil, northern Australia
Tropical savannas are known for their warm temperatures and seasonal rainfall.
What characterizes a Tropical Savanna?
Cover of grasses, warm temperatures, seasonal rainfall, compact soil, frequent fires
Frequent fires are often set by lightning.
What are the dominant plants in the Tropical Savanna?
Tall, perennial grasses; trees or shrubs
These plants are adapted to the savanna’s seasonal climate.
Which wildlife is dominant in the Tropical Savanna?
Lions, elephants, giraffes, zebras; eagles, termites
These species are well adapted to the savanna environment.
What are the geographical locations of Deserts?
Africa, Asia, the Middle East, North & South America, Australia
Deserts are found on every continent except Antarctica.
What characterizes a Desert?
Low precipitation; variable temperatures; soils rich in minerals but poor in organic material
This combination results in a harsh living environment.
What are the dominant plants in Deserts?
Cacti, creosote bush
These plants are adapted to conserve water.
Which wildlife is dominant in Deserts?
Mountain lions, mule deer, kangaroo, rats; owls, butterflies, flies, tortoises, rattlesnakes, lizards
Many desert animals are nocturnal to avoid daytime heat.
What are the geographical locations of Temperate Grasslands?
Central Asia, North America, Australia, central Europe, parts of South America
These regions have a mix of warm to hot summers and cold winters.
What characterizes Temperate Grasslands?
Warm to hot summers; cold winters; moderate, seasonal precipitation; fertile soils; occasional fires
Fires play a role in maintaining grassland ecosystems.
What are the dominant plants in Temperate Grasslands?
Lush, perennial grasses and herbs; most resistant to drought, fire, and cold
These plants contribute to the grassland’s biodiversity.
Which wildlife is dominant in Temperate Grasslands?
Coyotes, grizzly bears, antelope, rabbits, hawks, snakes, grasshoppers
These species thrive in the grassland habitat.
What are the two main categories of Aquatic biomes?
Freshwater and marine
Freshwater includes ponds, rivers; marine includes oceans and estuaries.
What defines Freshwater regions?
Having a low salt concentration — usually less than 1%
This low salt content is crucial for the survival of freshwater species.
What types of Freshwater regions exist?
Ponds and lakes; streams and rivers; wetlands
Each type supports unique ecosystems.
What is the significance of Marine regions?
Cover about three-fourths of the Earth’s surface; supply much of the world’s oxygen; provide rainwater
Marine algae are key to the global oxygen supply.
What conditions must exist for an ecosystem to be stable and self-sustaining?
Constant source of energy; organisms that can synthesize incoming energy; cycle of materials between organisms and environment
These conditions are essential for ecosystem health.
What is Ecological Succession?
The process by which an existing community is slowly replaced by another community
It can occur through primary or secondary succession.
What are the two types of Ecological Succession?
Primary and secondary
Primary occurs in areas with no existing life; secondary occurs after partial destruction of an existing community.
What does Human Ecology study?
The relationships between humans and their environment
It addresses the impact of human actions on ecological systems.
What are some environmental problems linked to human activities?
Global warming; pollution; land degradation; disease outbreaks
These issues stem from negligence or poor attitudes toward the environment.
What is the estimated world population currently?
Approximately 7 billion
This figure contributes to overpopulation concerns.
What is a consequence of Urbanization?
Disruption of existing ecosystems
Urbanization leads to the destruction of natural habitats and increased competition for resources.
Fill in the blank: An ecosystem requires a _______ source of energy.
[constant]
Energy sources can include sunlight or chemosynthesis.
What are the geographical locations of Tropical Savanna?
Large parts of eastern Africa, southern Brazil, northern Australia
Tropical savannas are known for their warm temperatures and seasonal rainfall.
What characterizes a Tropical Savanna?
Cover of grasses, warm temperatures, seasonal rainfall, compact soil, frequent fires
Frequent fires are often set by lightning.
What are the dominant plants in the Tropical Savanna?
Tall, perennial grasses; trees or shrubs
These plants are adapted to the savanna’s seasonal climate.
Which wildlife is dominant in the Tropical Savanna?
Lions, elephants, giraffes, zebras; eagles, termites
These species are well adapted to the savanna environment.
What are the geographical locations of Deserts?
Africa, Asia, the Middle East, North & South America, Australia
Deserts are found on every continent except Antarctica.
What characterizes a Desert?
Low precipitation; variable temperatures; soils rich in minerals but poor in organic material
This combination results in a harsh living environment.
What are the dominant plants in Deserts?
Cacti, creosote bush
These plants are adapted to conserve water.
Which wildlife is dominant in Deserts?
Mountain lions, mule deer, kangaroo, rats; owls, butterflies, flies, tortoises, rattlesnakes, lizards
Many desert animals are nocturnal to avoid daytime heat.
What are the geographical locations of Temperate Grasslands?
Central Asia, North America, Australia, central Europe, parts of South America
These regions have a mix of warm to hot summers and cold winters.
What characterizes Temperate Grasslands?
Warm to hot summers; cold winters; moderate, seasonal precipitation; fertile soils; occasional fires
Fires play a role in maintaining grassland ecosystems.
What are the dominant plants in Temperate Grasslands?
Lush, perennial grasses and herbs; most resistant to drought, fire, and cold
These plants contribute to the grassland’s biodiversity.
Which wildlife is dominant in Temperate Grasslands?
Coyotes, grizzly bears, antelope, rabbits, hawks, snakes, grasshoppers
These species thrive in the grassland habitat.
What are the two main categories of Aquatic biomes?
Freshwater and marine
Freshwater includes ponds, rivers; marine includes oceans and estuaries.
What defines Freshwater regions?
Having a low salt concentration — usually less than 1%
This low salt content is crucial for the survival of freshwater species.
What types of Freshwater regions exist?
Ponds and lakes; streams and rivers; wetlands
Each type supports unique ecosystems.
What is the significance of Marine regions?
Cover about three-fourths of the Earth’s surface; supply much of the world’s oxygen; provide rainwater
Marine algae are key to the global oxygen supply.
What conditions must exist for an ecosystem to be stable and self-sustaining?
Constant source of energy; organisms that can synthesize incoming energy; cycle of materials between organisms and environment
These conditions are essential for ecosystem health.
What is Ecological Succession?
The process by which an existing community is slowly replaced by another community
It can occur through primary or secondary succession.
What are the two types of Ecological Succession?
Primary and secondary
Primary occurs in areas with no existing life; secondary occurs after partial destruction of an existing community.
What does Human Ecology study?
The relationships between humans and their environment
It addresses the impact of human actions on ecological systems.
What are some environmental problems linked to human activities?
Global warming; pollution; land degradation; disease outbreaks
These issues stem from negligence or poor attitudes toward the environment.
What is the estimated world population currently?
Approximately 7 billion
This figure contributes to overpopulation concerns.
What is a consequence of Urbanization?
Disruption of existing ecosystems
Urbanization leads to the destruction of natural habitats and increased competition for resources.
Fill in the blank: An ecosystem requires a _______ source of energy.
[constant]
Energy sources can include sunlight or chemosynthesis.
What are the consequences of poor farming practices?
Depletion of nutrients in the soil, loss of top soil, erosion
Poor farming practices include over-farming and over-grazing.
What health hazards can arise from the abuse of pesticides and herbicides?
Land contamination, disruption in the food chain, food poisoning, various health hazards
These abuses affect both human health and the environment.
Define pollution.
The introduction of contaminants into the natural environment that causes adverse change.
What forms can pollution take?
Noise, heat (light), chemical substances
These forms of pollution can impact various aspects of the environment.
List some common pollutants.
- Organic wastes
- Inorganic chemicals
- Heavy metals
- Oil spills
- Radioactive wastes
- Greenhouse gases
- Pathogens
What are the serious risks posed by pollutants?
Contamination of land, water, air, health risks, environmental degradation.
What is a key environmental solution to restoring the environment?
Developing environmentally safe and cost-effective solutions.
Name some measures to restore the environment.
- Population control
- Bioremediation of contaminated land and water
- Clean-up technologies
- Encouraging renewable energy and resources
- Soil, forest, and wildlife conservation
- Agricultural best practices
Fill in the blank: The use of _______ is an agricultural best practice that helps in soil conservation.
crop rotation
True or False: Erosion prevention technologies are included in agricultural best practices.
True
What is bioremediation?
The process of using organisms to remove or neutralize contaminants from the environment.
