TEST 2 Flashcards
What are autotrophs?
Organisms that produce organic molecules from inorganic substances using sunlight.
What is the main function of heterotrophs?
Obtain organic material from other organisms.
Where does photosynthesis primarily occur in plants?
In the leaves, specifically within the mesophyll layer.
What is the primary role of chloroplasts?
Site of photosynthesis in plant cells.
What is the equation for photosynthesis?
6CO2 + 6H2O + Solar Energy => Glucose + 6O2
What are the two stages of photosynthesis?
Light Reactions and Calvin Cycle.
What is the primary product of the light reactions?
O2, NADPH, and ATP.
What is the role of chlorophyll in photosynthesis?
Absorbs light energy to drive the process.
What is the difference between PS1 and PS2?
PS1 absorbs light at 700 nm and PS2 at 680 nm.
What is photorespiration?
A process where Rubisco fixes oxygen instead of carbon, reducing sugar production.
What are C4 plants adapted for?
Minimizing photorespiration by incorporating CO2 into 4-carbon compounds.
What happens during anaphase?
Sister chromatids separate and move toward the poles of the cell.
What is the function of the mitotic spindle?
Controls chromosome movement during mitosis.
What are the three phases of the Calvin Cycle?
- Carbon Fixation * Reduction * Regeneration of RuBP
What is the role of cyclins and CDKs in the cell cycle?
Regulate the timing of cell division.
What is the G1 checkpoint responsible for?
Checking cell size, growth factors, and organelles before division.
Fill in the blank: The main photosynthetic pigment in plants is _______.
[Chlorophyll]
True or False: All plants are photo-autotrophs.
False.
What is the primary purpose of mitosis?
Growth, development, and repair of tissues.
What forms during cytokinesis in animal cells?
A contractile ring of microfilaments that creates a cleavage furrow.
What is the significance of the electron transport chain in photosynthesis?
Drives the creation of a proton gradient for ATP synthesis.
What happens to chlorophyll when it absorbs light?
An electron gains energy and moves from the ground state to an excited state.
What does the term ‘chemiosmosis’ refer to in chloroplasts?
ATP generation as protons diffuse back into the stroma.
What is the purpose of the stroma in chloroplasts?
Site for the Calvin Cycle where sugar is formed from CO2.
What are the two types of cells in C4 plants?
- Bundle Sheath * Mesophyll
What is necrosis?
Cell death due to low oxygen, toxins, or ATP depletion.
What is the role of Rubisco in the Calvin Cycle?
Catalyzes the fixation of CO2.
What is the main disadvantage of photorespiration?
Lowers production of sugars and limits plant growth.
What is a karyotype?
An image that reveals an orderly arrangement of chromosomes.
What happens during the G2 checkpoint?
Checks for DNA damage and ensures DNA synthesis is complete.
What is the role of centrosomes in cell division?
Organize the mitotic spindle.
What is a key characteristic of apoptosis?
Programmed cell death involving chromatin condensation and membrane blebbing.
What is the typical A:B ratio in chlorophylls?
6:1
What happens in the light reactions of photosynthesis?
Water is split, releasing oxygen and generating ATP and NADPH.
What is the significance of the Rubisco enzyme?
It is crucial for carbon fixation in the Calvin Cycle.
What is the primary output of the Calvin Cycle?
Sugar (G3P).
What are organelles?
Cellular structures that perform specific functions
What happens to mRNAs without approval?
They enter G0
What external factors influence the decision to divide?
Growth factors, PDGF, density-dependent inhibition
What is necrosis?
Cell death due to low oxygen, toxins, or ATP depletion
What are the characteristics of apoptosis?
- Programmed death
- Chromatin condensation
- Membrane blebbing
- No inflammation
What does ABCDE recognition refer to in cancer detection?
- Asymmetry
- Border irregularity
- Color
- Diameter (over 6 mm)
- Evolving
What are the key factors in cancer inhibition?
- Dependence
- Anchorage
- Density
- Encapsulation
What characterizes cancer cells?
- Uncontrolled mitosis
- Exceeds Hayflick limit
- Can metastasize
What factors contribute to aging?
- Telomere shortening
- Chronological age
- Oxidative stress
- Glycation
What are proto-oncogenes?
Normal variants of genes that code for growth factors
What are tumor suppressor genes?
Genes that prevent uncontrolled cell growth
What is the relationship between mutations and cancer cells?
Mutations lead to the formation of oncogenes and destruction of tumor suppressor genes
What is the sequence of mutations in colorectal cancer?
- Mutation on chromosome 5
- Mutation on chromosome 12
- Mutation on chromosome 18
- Mutation on chromosome 17
What are the characteristics of inherited cancer?
- Somatic mutations
- Familial cancer
- Germ line mutations
What are common cancers in the US for women?
- Skin
- Breast
- Lung
- Colorectal
What are the risk factors for breast cancer?
- Mammary gland virus
- Excess HER2 protein
- Mutated BRCA genes
- Lifestyle factors
What are the four characteristics of cancer staging?
- Size of the cancer
- Spread (invasive or non-invasive)
- Involvement of lymph nodes
- Distant spread
What are important lymph node locations?
- Epitrochlear
- Axillary
- Inguinal
- Pectoral
- Supraclavicular
- Subclavian
- Cervical
What are the risk factors for esophageal cancer?
- Age
- Males
- Tobacco smoking
- Heavy alcohol consumption
- Obesity
What are the clinical symptoms of prostate cancer?
- Difficulty urinating
- Frequent urges to urinate at night
- Loss of bladder control
- Pain during urination
- Blood in urine
What treatments are available for cancer?
- Radiation
- Surgery
- Hormone therapy
- Chemotherapy
- Immunotherapy
How do cancer cells escape detection?
- Produce normal proteins
- Produce oncofetal proteins
- Block immune cell detection
What are carcinogens?
- Tobacco
- Alcohol
- Ultraviolet light
- HPV
What is asexual reproduction?
One cell passes all of its genes to the offspring
What is the difference between diploid and haploid cells?
Diploid cells have 46 chromosomes, haploid cells have 23
What are sex chromosomes?
X and Y chromosomes that determine the sex of an individual
What is meiosis?
Process that reduces the number of chromosome sets from diploid to haploid
What is the result of meiosis?
4 haploid daughter cells that are genetically different
What are the contributing mechanisms to genetic variation?
- Crossing over
- Independent assortment
- Random fertilization
- Mutations
- Natural selection
What is nondisjunction?
Failure of chromosome pairs to separate during meiosis
What is necrosis?
- Cell death due to low oxygen
- Inflammation
- Random fragmentation
What is apoptosis?
- Programmed cell death
- No inflammation
- Involves chromatin condensation
Who is known as the father of genetics?
Gregor Mendel
What does a monohybrid cross involve?
A cross between purebred parents differing in one trait
What is a testcross?
Cross between an individual with a dominant phenotype and a homozygous recessive individual
What are the laws of inheritance proposed by Mendel?
- Law of segregation
- Law of independent assortment
What is Mendel’s Law of Inheritance?
It refers to the principles of genetic inheritance discovered by Gregor Mendel.
What does the Law of Segregation state?
Alleles of each gene segregate from each other during gamete formation.
How many alleles does each gamete carry?
1 allele.
What is the Law of Independent Assortment?
Genes for different traits can segregate independently of other genes during gamete formation.
What is a testcross?
A cross between an individual with a dominant phenotype (unknown genotype) and a homozygous recessive individual.
What are pedigrees used for?
To analyze the inheritance of traits across generations.
Name two examples of human traits that follow Mendel’s principles.
- Earlobe Attachment
- Tongue Rolling
True or False: Dominant traits are always more common than recessive traits.
False.
What are wild type traits?
The typical most common trait found in nature of an organism.
What does geographic isolation lead to?
Inbreeding.
What is the Hapsburg Jaw an example of?
An increase in the chance that offspring are homozygous for a harmful recessive trait.
What are lethal alleles?
Alleles that can cause death when homozygous.
Most human disorders are of what type?
Recessive.
Who are carriers in genetics?
Individuals who are heterozygous for a disorder.
What is PKU?
A disorder caused by deficiency in phenylalanine hydroxylase.
What are common symptoms of PKU?
- Progressive intellectual disabilities
- Seizures
- Distinct odor in breath/skin/urine
What is the most common lethal genetic disorder in the US?
Cystic Fibrosis.
What causes Cystic Fibrosis?
A recessive allele that impairs transport of Cl- ions in lung cells.
What mutation causes Sickle Cell Anemia?
A mutation in the 6th amino acid of the B globin gene.
What are the symptoms of Huntington’s Disease?
- Involuntary movements
- Degeneration in brain and spinal cord.
What is Achondroplasia?
A dominant form of dwarfism.
What syndrome is characterized by defects in connective tissue?
Marfan Syndrome.
What is Polydactyly?
Having more than 5 fingers or toes.
What is Brachydactyly?
Shortening of fingers and toes.
What is Neurofibromatosis?
A non-cancerous tumor disorder along the nervous system.
What is Progeria?
A condition causing accelerated aging.
What is incomplete dominance?
When hybrids have an appearance between the two phenotypes of the parents.
What is codominance?
When hybrids express both dominant traits.
What is polygenic inheritance?
When many genes affect a single trait.
What is pleiotropy?
When one gene affects many traits.
What are linked genes?
Genes located close together on a chromosome.
What do sex-linked genes influence?
The inheritance of certain traits.
What is an example of a sex-linked disorder?
- Colorblindness
- Hemophilia
What is male pattern baldness an example of?
A sex-influenced trait.
What is the dominant trait that influences male pattern baldness?
Levels of DHT and androgen receptors on the X gene.
