Flashcards
(T/F) Photosynthesis occurs in the spongy layer of the mesophyll of a leaf
False.
Photosynthesis occurs in the palisade layer of the mesophyll of a leaf.
What are the two types of roots
Traproot & Fibrous
What happens when the turgor pressure in cells decreases too much?
The plant wilts.
What is a fixed action pattern?
A complex, coordinated, innate behavioral response to specific patterns of stimulation.
The sign stimulus/releaser elicits the highly stereotyped behavior that must be completed once begun.
(T/F) Imprinting can only take place during a brief critical period
True
In classical conditioning, in order to elicit the conditioned response from the conditioned stimulus, what must be presented along with the conditioned stimulus during the conditioning period?
The combination of presenting the conditioned stimulus along with the unconditioned stimulus during the conditioning period elicits the conditioned response later on.
(T/F) Operant conditioning may be used only to make an organism avoid a certain type of behavior.
False.
Operant conditioning may be utilized to make an organism repeat or avoid a certain type of behavior, depending on whether that behavior is associated with a reward or punishment, respectively.
Place the following objects in the order in which they exist in the energy pyramid, from the top to the bottom: Secondary costumers, producers, sunlight, detrivores, primary consumers.
Sunlight -> Producers -> Primary consumers -> secondary consumers -> detrivores.
What are omnivores?
Omnivores are heterotrophs that consume both plants and animals
What role do animals have in the nitrogen cycle?
The wastes and dead remains of plants and animals provide the amonia used by nitrifying bacteria to produce nitrites and nitrogen dioxide and used by nitrifying bacteria to produce free nitrogen in the atmosphere.
(T/F) Nitrogen fixation occurs in the stalks of leafy green vegetable plants.
False.
Bacteria on the roots of legumes are responsible for nitrogen fixation.
(T/F) Chemosynthetic bacteria do not rely on photosynthesis for survival.
True.
What are the three directly biological sources of CO2 in the environment?
Respiration
Photosynthesis
Decomposition
of plants and animals materials by bacteria of decay.
Place the following in order of levels of biological organization, from the smallest to the largest:
Biosphere, Community, Ecosystem, Organism, Population
Organism -> Population -> Community -> Ecosystem -> Biosphere
What are the characteristics of the population growth curve that occurs more often in nature?
The logistic growth curve is an S-shaped curve that plateaus @ a value of K (The carrying capacity).
The max # of organisms the environment can support result of the limited amount of resources.
(T/F) In comensalistic relationship, both organisms involved benefit.
False.
Comensalistic relationship: One organism benefits the host not harmed.
What is the principle behind ecological succession?
Organisms that live in a given environment alter the environment to make the living conditions less favorable for itself and more favorable for the community that succeeds it.
What are the characteristics of Tundra?
Permanent Permafrost, little h2o, near poles, small plants, caribou, polar bears, artic foxes & hares.
Which environment with the greatest diversity of plants and animals?
Tropical rain forest.
What type of nervous system do annelids employ?
Primitive central nervous system with a brain composed of fused ganglia.
What type of nervous system do arthropods employ?
Primitive central nervous system with a brain composed of fused ganglia with specialized sense organs.
(T/F) Coelenterates employ a nerve net as their nervous system?
True
What is asexual reproduction?
Any reproductive process that does not involve the fusion of gametes.
(T/F) Binary fission (Prok) entails an equal division of cytoplasm as well as nuclear contents.
True
(T/F) Budding entails an equal division of cytoplams as well as nuclear contents.
False.
Budding is an asexual reproductive process characteristic of yeast in which there is an equal divisio of genetic material and unequal division of cytoplasm.
The daughter cell may pinch off and live independenltly, or remain connected and live as part of the larger colony.
What is parthenogenesis?
Development of an egg in the absence of fertilization, resulting in a haploid organism.
ie: frogs
What type of excretory system do annelids employ?
Excrete urea through nephridia in skin.
What type of excretory system do arthropods employ?
Produce uric acid in the malpighian tubules and eliminate it through rectum.
(T/F) In coelenterates, ammonia and CO2 diffuse directly into the environment.
True
(T/F) In Protozoans, ammonia and CO2 diffuse directly into the environment.
True
What are the five kingdoms of living organisms?
Monera Protista Fungi Plantae Animalia
What are the subdivisions used classifying an organism withing a given kingdom?
Kingdom Phylum Subphylum Class Order Family Genus Species
What is the founder effect?
loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
(T/F) Convergent evolution is due to homology.
False.
Convergent evolution sis due to analogy
What are the name of the male and female reproductive organs of a plant and their parts?
Male: Stamen
-Filament
-long stalk-like segment
-anther
-small sac @ top of the filament
Female: Pistil
-stigma (the sticky surface that catches pollen)
-style (the area the pollen tube grows down)
-Ovary (eventually forms the fruit and contains seeds called ovules)
Where and what type of gametes are formed in male and female plants?
Pollen is produced in the anther; the embryo sac forms in the ovules.
How many N are the plant gametes, embryo and endosperm?
plant: 1N
Embryo: 2N
Endosperm: 3N
What is phototropism?
Phototropism is the phenomenon in which a plant grows toward its light source.
What type of circulatory system do annelids employ?
Closed.
Simple circulatory system
What type of circulatory system do arthropods employ?
Open circulatory system
What type of circulatory system do coelenterates employ?
Diffusion
cyclosis
What type of circulatory system do protozoans employ?
Diffusion, Cyclosis
What type of respiratory system do annelids employ?
Gas exchange via diffusion through moist skin (Worms)
What type of respiratory system do arthropods employ?
Gas exchange through respiratory tracheae which branch extensively through the body. air enters and leaves the trachea via openings on the surface called spiracles.
(Grasshopper)
What type of respiratory system do coelenterates employ?
Gas exchange via diffusion through individual cell membranes contacting aqueous environment.
What type of respiratory system do Protozoans employ?
Gas exchange via diffusion through individual cell membranes contacting aqueous environment.
What type of Digestive system do annelids employ?
One-way, two opening digestive tract
Worms
What type of Digestive system do arthropods employ?
One-way, tow opening digestive tract
What type of Digestive system do coelenterates employ?
Extracellular digestion in the gastrovascular cavity (Hydra)
What type of Digestive system do protozoans employ?
Intracellular Digestion
What happens during the light cycle?
Light energy is used to produce ATP via photophosphorylation and photolysis (Splitting of water), while forming O2 and NADPH
What happens during the dark calvin cycle?
ATP & NADPH formed during the light reaction are used to fix CO2 into organic material. Light is not required, but the dark cycle usually occurs during the day when the light reaction provides ATP and NADPH
(T/F) Sugars may be synthesized once the light cycle has shut down?
True.
The dark calvin cycle can continue without light.
What molecule provides the reducing power needed during the synthesis of sugar?
NADPH
(T/F) Photosynthetic organisms use CO2 and H2O to produce carbohydrates, proteins and lipids?
True
In what organelle does photosynthesis occur?
What photosynthetic pigment is used?
Organelle: Chloroplast
Pigment: Chlorophyll
What structure lets gases in and out of the plant?
What regulars the opening and closing of these structures?
Stomates
Guard Cells.
What is the net reaction for photosynthesis?
6 CO2+ 12 H2O+ Light Energy -> C6H12O6 + 6 H2O
Describe Convergent Evolution
Independent development of similar characteristics by non-related groups.
Describe Parallele Evolution
Process whereby related groups independently develop similar characteristics due to analogous environmental pressures.
Describe Divergent Evolution
Process whereby related groups independently develop dissimilar characteristics.
when are two populations descending from the same ancestral stock considered to be different species?
when they can not longer interbreed and produce viable offspring
What is adaptive radiation
emergence of a number of distinct lineages from a single ancestral species.
The different lineages usually result when a group begind to exploit a different niche.
How does genetic drift diff from gene flow?
Genetic drift: changes in gene pool due to change,
Gene Flow: changing gene pool due to the migration of individuals.
(T/F) Stabilizing selection maintains a well adapted uniform character in a population.
True
How does disruptive selection affect the phenotype of a population?
Disruptive selection favors the phenotypical extremes, leading to the expression of two or more phenotypic forms.
How does directional selection affect the phenotype of a population?
Directional selection favors the expression of one phenotypical extreme.
What are the 5 necessary conditions for the Hardy-Weinberg equation to hold true.
- No immigration
- No mutation
- Large population
- Random mating
- Genes in a population are equally successful @ reproducing
(T/F) Lamarck’s theory of evolution is based on the inheritance of acquired characteristics
True
(T/F) Lamarckian evolution holds true in a number of different circumstances
False
Define fitness according to Darwin
Ability for an organism to mate and produce fertile offspring
What is an operon?
gene that regulates bacterial transcription.
What is an inducible system?
requires the presence of an inducer for transcription to occur.
What is a repressible system?
repressible system is in a constant state of transcription unless a corepressor is present to inhibit transcription.
Describe the lytic and lysogenic cycles
lyric cycle: results in the production of new progeny that cause the cell to lyse.
Lysogenic Cycle: results in incorporation of the viral DNA into the bacterial DNA where it remains inactive.
A lysogenic cycle may progress to a lytic cycle
What are the threw mechanisms by which bacteria can increase genetic variability?
- Transformation: incorporation of foreign chromosome fragments.
- Conjugation: Transfer of genetic material between two bacteria.
- Transduction: Virus carries DNA between two bacteria.
What is a retrovirus?
RNA virus that codes for the enzyme reverse transcriptase, which uses the RNA as a template for DNA synthesis.
What is a prophage (provirus)?
Bacterial virus that has integrated into its host cell genome.
What are the three stages of polypeptide synthesis?
Initiation, elongation & termination
What are the three types of base pairs mutations that can occur during the protein synthesis?
Substitutions, insertions, and deletions.
What is transcription?
process where mRNA is synthesized from a DNA template.
What is translation?
process where proteins are synthesized from a mRNA template.
What is an exon?
An intron?
exon: coding sequence on a gene.
Intron: non-coding sequence on a gene.
What is a codon?
3 base sequence on mRNA that codes for a specific amino acids.
What is an anticodon?
3-base sequence on tRNA that is complementary to a mRNA codon.
(T/F) DNA synthesis proceeds in the 3’ to 5’ direction.
False.
DNA synthesis proceeds in the 5’ to 3’ direction.
What are the three types of RNA, and what are their functions?
Messenger RNA (mRNA): contains the codons for peptide chain synthesis. Transfer RNA (tRNA): transports amino acids to the ribosome during protein synthesis. Ribosomal RNA (rRNA): structural component of ribosomes.
Name the four nitrogenous bases in DNA
Adenine, Cytosine, Guanine, Thymine.
Name the purines.
Name the pyrimidines.
purines: adenine and guanine.
pyrimidines: cytosine and thymine.
What is the base-pairing in DNA?
How many bonds hold the bases together?
Adenine- Thymine (2 H bonds)
Cytosine- Guanine (3 H bonds)
Name three differences between RNA and DNA
RNA uses ribose instead of deoxyribose.
RNA replaces thymine with Uracil
RNA is single-stranded
(T/F) Females can express a sex-linked recessive trait.
True.
What is nondisjunction?
the failure of homologous chromosomes or sister chromatids to separate properly during cellular reproduction.
(T/F) In humans, most sex-linked genes are located on the Y chromosome.
False. Most are located on X chromosomes.
What percentage of daughters will inherit their father’s sex-linked gene?
100%
What percentage of sons will inherit their father’s sex linked gene?
0%
What percentage of sons will inherit their mother’s sex linked gene (assuming a heterozygous mother)?
50%
Red flowers crossed with white flowers yield pink flowers. What kind of dominance is portrayed in this example?
Incomplete dominance
What is endocytosis?
cell membrane invaginates, forming an intracellular vesicle containing extracellular medium.
What is exocytosis?
cell fuses with the cell membrane and releases its contents to the extracellular medium.
(T/F) Facilitated diffusion requires energy.
False.
all forms of diffusion are passive processes.
Define active transport.
net movement of dissolved particles against their concentration gradient with the help of carrier molecules.
ATP required.
(T/F) Active transport requires energy.
True
What is a membrane receptor?
protein or glycoprotein that binds to molecules in the extracellular environment.
Can small polar and non-polar molecules easily cross the cell membrane?
Yes because of their size.
How does a large charged molecule cross the cell membrane?
via carrier protein
(T/F) The nucleus is surrounded by a single-layered membrane.
False, it’s double layered.
Given: P= dominant (purple) p= recessive (White)
What would be the phenotypic ratio of a PP x pp cross?
100% purple
Given: P= dominant (purple) p= recessive (White)
What would be the phenotypic ratio of a Pp x Pp cross?
75% purple : 25% white
Given: P= dominant (purple) p= recessive (White)
What would be the phenotypic ratio of a Pp x pp cross?
50% purple: 50% white
Given: P= dominant (purple) p= recessive (White)
What would be the genotypic ratio of a Pp x pp cross?
50% Pp : 50% pp
Given: P= dominant (purple) p= recessive (White)
What would be the genotypic ratio of a Pp x Pp cross?
25% PP : 50% Pp : 25% pp
Summarize Mendel’s 1st Law (Law of segregation)
Law of segregation states that alleles segregate during meiosis specifically:
- Gene exist in alternative forms (alleles)
- An individual inherits two alleles for each trait, one from each parent.
- The two alleles segregate during meiosis.
- if two different alleles are present, only on will be fully expressed.
Summarize Mendels 2nd Law (Law of independent assortment)
sties that alleles of unlinked genes assort independently during meiosis
What are alleles?
different forms of the same gene they occupy same position on homologous chromosomes.
Define genotype
genetic makeup of an individual.
Define Phenotype
physical manifestation
Define Homozygous
Homozygous have two copies of the same allele for a given trait.
Define heterozygous
Heterozyous have two different alleles for a given trait.
Which type of photoreceptor cell is specialized for color vision?
Which type is specialized for low light conditions?
Cones: Color
Rods: Night
What is the fovea?
are in the retina with high density of cones.
what are the components of the middle ear?
Tympanic membrane
Malleus
Incus
Stapes
What are the components of the inner ear?
Cochlea
Corti
Which part of the nervous system radiates the body for “flight or fight”?
Sympathetic Nervous system.
What are the functions of the parasympathetic division of the nervous system?
slows down body and conserves energy.
Which division of the nervous system inhibits digestion?
Sympathetic
(T/F) Dorsal root ganglia house the cell bodies of sensory root fibers
True