Mixed Review

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of competition occurs when two species indirectly compete for the same limited resource?

Apparent competition

Intraspecific competition

Resource partitioning

Exploitation competition (correct)

Resource partitioning allows different species to coexist by occupying the same niche.

False

What is the term for indirect competition caused by a shared predator?

Apparent competition

Intraspecific competition occurs when members of the same __________ compete for limited resources.

species Signup and view all the answers

Match the following types of competition with their definitions:

Exploitation competition = Indirect competition for shared resource Resource partitioning = Coexistence by occupying different niches Apparent competition = Decline in a species due to a shared predator Intraspecific competition = Competition among the same species Signup and view all the answers

What is the main function of the citric acid cycle?

Generating electron carriers for ATP production Signup and view all the answers

The citric acid cycle occurs in the nucleus of the cell.

False Signup and view all the answers

Name one product generated from each cycle of the citric acid cycle.

NADH, FADH2, CO2, or ATP Signup and view all the answers

The citric acid cycle begins with the combination of acetyl CoA and __________.

oxaloacetate Signup and view all the answers

Match the steps of the citric acid cycle with their corresponding outputs:

Citrate to Isocitrate = Conversion with no loss of carbon Isocitrate to Alpha-ketoglutarate = CO2 loss and oxidation Succinyl CoA to Succinate = Conversion with ATP production Malate to Oxaloacetate = Oxidation with NADH production Signup and view all the answers

What is the first substrate used in glycolysis?

Glucose Signup and view all the answers

In the energy payoff phase of glycolysis, 4 ATP molecules are produced.

False Signup and view all the answers

What enzyme converts fructose-6-phosphate to fructose-1,6-bisphosphate?

Phosphofructokinase (PFK) Signup and view all the answers

Glyceraldehyde 3-phosphate (G3P) is converted to __________ during glycolysis.

Pyruvate Signup and view all the answers

Match the following components of glycolysis with their functions:

Hexokinase = Converts glucose to glucose-6-phosphate Isomerase = Converts glucose-6-phosphate to fructose-6-phosphate NAD+ = Electron carrier, reduced to NADH ATP = Energy currency used in the investment phase Signup and view all the answers

Where does glycolysis occur within a cell?

Cytoplasm Signup and view all the answers

In prokaryotes, the electron transport chain occurs in the mitochondria.

False Signup and view all the answers

What molecule is produced from glycolysis that is subsequently used in the Krebs cycle?

Pyruvate Signup and view all the answers

Glycolysis is the first step in the process of __________.

cellular respiration Signup and view all the answers

Match the following cell components with their functions in cellular respiration:

Nucleus = Houses and protects DNA Golgi apparatus = Modifies and packages proteins Mitochondria = Site of Krebs cycle and electron transport chain Cell membrane = Involvement in oxidative phosphorylation in prokaryotes Signup and view all the answers

What is the role of the pilus in conjugation?

It facilitates the direct transfer of DNA between bacteria. Signup and view all the answers

Transformation involves the uptake of DNA by bacteria with no specialized structures.

True Signup and view all the answers

What type of genetic material is exchanged during transduction?

Bacterial DNA Signup and view all the answers

In transformation, bacteria incorporate __________ DNA.

extracellular Signup and view all the answers

Match the type of horizontal gene transfer with its description:

Conjugation = Transfer of DNA through a pilus Transformation = Uptake of loose DNA from the environment Transduction = Transfer of DNA by a virus F plasmid = Plasmid used in conjugation Signup and view all the answers

What enzyme is activated from pepsinogen in the stomach?

Pepsin Signup and view all the answers

Cholecystokinin is released in the stomach to help with protein digestion.

False Signup and view all the answers

What is the primary function of enteropeptidase in protein digestion?

To activate trypsin from trypsinogen. Signup and view all the answers

The process of protein digestion begins with proteins being broken down by __________.

proteases Signup and view all the answers

Match the following enzymes with their role in protein digestion:

Pepsin = Digests proteins in the stomach Trypsin = Activates chymotrypsin Chymotrypsin = Breaks down polypeptides Enteropeptidase = Activates trypsin Signup and view all the answers

What stimulates the gallbladder to release bile?

Cholecystokinin (CCK) Signup and view all the answers

The liver directly absorbs fats after producing bile.

False Signup and view all the answers

What happens to large fat globules in the small intestine?

They are emulsified by bile. Signup and view all the answers

The __________ concentrates and stores bile produced by the liver.

gallbladder Signup and view all the answers

Match the following steps in fat absorption with their descriptions:

1 = Bile is secreted into the duodenum 2 = Bile emulsifies fat 3 = Lipases digest the emulsified fat 4 = Bile is produced by the liver Signup and view all the answers

What type of mutation leads to the formation of an oncogene?

Gain-of-function mutation Signup and view all the answers

Tumor-suppressor genes require a single mutation to cause cancer.

False Signup and view all the answers

What is the key difference between proto-oncogenes and tumor-suppressor genes in relation to cancer?

Proto-oncogenes promote cancer through gain-of-function mutations, while tumor-suppressor genes promote cancer due to loss-of-function mutations. Signup and view all the answers

A __________ mutation in both copies of tumor-suppressor genes leads to cancerous proliferation.

loss-of-function Signup and view all the answers

Match the type of mutation with their corresponding effects:

Gain-of-function mutation = Converts proto-oncogenes to oncogenes Loss-of-function mutation = Inactivates tumor-suppressor genes One-hit hypothesis = Requires one mutation to cause cancer Two-hit hypothesis = Requires two mutations to cause cancer Signup and view all the answers

What is the main function of a genomic library?

To store the total genomic DNA from a single organism Signup and view all the answers

Restriction fragment length polymorphisms (RFLPs) are used in DNA fingerprinting.

True Signup and view all the answers

Name one method used to screen bacteria for a gene of interest.

Antibiotic resistance or color change methods Signup and view all the answers

In SDS-PAGE, proteins are separated based on their and .

size, charge Signup and view all the answers

Match the following techniques with their purposes:

ELISA = Detecting specific antigens RFLPs = Genetic identification SDS-PAGE = Separating proteins Genomic library = Storing genomic DNA Signup and view all the answers

What process occurs when RuBisCo binds to oxygen instead of carbon dioxide?

Photorespiration Signup and view all the answers

CAM plants open their stomata during the day to absorb CO2.

False Signup and view all the answers

What is the primary advantage of CAM photosynthesis in desert plants?

It minimizes water loss and decreases photorespiration. Signup and view all the answers

In C4 plants, the carbon dioxide is first fixed by the __________ in the mesophyll cells.

C4 intermediate Signup and view all the answers

Match the types of plants with their photosynthetic characteristics:

C3 plants = Use Calvin cycle directly C4 plants = Utilize C4 intermediate CAM plants = Open stomata at night All types = Perform photosynthesis Signup and view all the answers

What happens to the number of chromosomes in a zygote if nondisjunction occurs during meiosis I?

The zygote will have 45 or 47 chromosomes. Signup and view all the answers

Nondisjunction can only happen during meiosis I.

False Signup and view all the answers

What is the term used to describe the condition of having an abnormal number of chromosomes?

aneuploidy Signup and view all the answers

If nondisjunction occurs during meiosis I, the resulting gametes can have either n+1 or n-1 chromosomes, which translates to or chromosomes after fertilization.

47, 45 Signup and view all the answers

Match the terms related to nondisjunction with their definitions:

Nondisjunction = Failure of chromosomes to separate properly during cell division Meiosis I = First meiotic division where homologous chromosomes are separated Aneuploidy = Condition of having an abnormal number of chromosomes Gametes = Sex cells resulting from meiosis Signup and view all the answers

Which structure is developed from the ectoderm?

Epidermis layer of skin Signup and view all the answers

The mesoderm gives rise to the lining of the digestive system.

False Signup and view all the answers

What does the mnemonic 'means-oderm' help to remember?

The derivatives from mesoderm that are the means needed to move around. Signup and view all the answers

The _____ develops into the central nervous system.

ectoderm Signup and view all the answers

Match the following germ layers with their derived structures:

Ectoderm = Lining of lungs Mesoderm = Central nervous system Endoderm = Adrenal cortex Signup and view all the answers

What is the percentage of the population that is heterozygous for the allele?

42% Signup and view all the answers

In Hardy-Weinberg equilibrium, q2 represents the frequency of homozygous dominant individuals.

False Signup and view all the answers

What do the symbols p and q represent in the equation p + q = 1?

p represents the frequency of the dominant allele, and q represents the frequency of the recessive allele. Signup and view all the answers

The frequency of homozygous recessive individuals in the population is represented by ________.

q2 Signup and view all the answers

Match the following equations with their meanings:

p + q = 1 = Represents the sum of allele frequencies p2 + 2pq + q2 = 1 = Represents the sum of genotype frequencies q2 = Frequency of homozygous recessive individuals 2pq = Frequency of heterozygous individuals Signup and view all the answers

What is one of the products formed during beta-oxidation?

Acetyl-CoA Signup and view all the answers

NADH is produced as a result of beta-oxidation.

True Signup and view all the answers

Where does beta-oxidation occur within a cell?

Mitochondrial matrix Signup and view all the answers

In beta-oxidation, fatty acids are converted into ________.

Acetyl-CoA Signup and view all the answers

Match the substances to their roles in beta-oxidation:

Fatty acids = Reactants NADH = Product Acetyl-CoA = Product NAD+ = Reactant Signup and view all the answers

What is the primary function of the Na+/K+ ATPase?

To maintain an electrochemical gradient by moving Na+ out and K+ in Signup and view all the answers

Na+/K+ ATPase hydrolyzes ATP to pump ions against their concentration gradients.

True Signup and view all the answers

How many Na+ ions does the Na+/K+ ATPase pump out of the cell?

Three Signup and view all the answers

If the Na+/K+ ATPase cannot hydrolyze ATP, Na+ will concentrate the cell and K+ will concentrate the cell.

inside; outside Signup and view all the answers

Match the following ion movements with their corresponding concentrations when the Na+/K+ ATPase is inactive:

Na+ = Increased inside the cell K+ = Increased outside the cell Signup and view all the answers

Which characteristic is NOT associated with arthropods?

Radial symmetry Signup and view all the answers

Annelids possess exoskeletons.

False Signup and view all the answers

What type of symmetry do adult echinoderms exhibit?

Radial symmetry Signup and view all the answers

All arthropods are characterized by jointed __________.

appendages Signup and view all the answers

Match the following phyla with their characteristics:

Annelida = Segmented worms without exoskeletons Chordata = Possesses a notochord during development Echinodermata = Radial symmetry and no segmentation Rotifera = Microscopic aquatic animals without segmentation Signup and view all the answers

Where does filtration take place in the excretory system?

Glomerulus and Bowman's capsule Signup and view all the answers

The loop of Henle has both ascending and descending limbs that function in filtration.

False Signup and view all the answers

What is the primary function of the proximal tubule?

Reabsorption and secretion Signup and view all the answers

In the excretory system, the process of _________ eliminates remaining waste products and excess water from the body.

excretion Signup and view all the answers

Match the following nephron processes with their descriptions:

Filtration = Movement of fluids and solutes from blood into renal tubules Reabsorption = Reabsorption of substances from tubules back into the bloodstream Secretion = Direct secretion of ions and waste products into the tubules Excretion = Elimination of waste products and excess water from the body Signup and view all the answers

What occurs during the luteal phase of the ovarian cycle?

Follicle develops into the corpus luteum Signup and view all the answers

The secondary oocyte is released during the luteal phase.

False Signup and view all the answers

What hormones are primarily secreted by the corpus luteum?

Estrogen and progesterone Signup and view all the answers

During the follicular phase, FSH stimulates the maturation of _____ follicles into estrogen-secreting secondary follicles.

primary Signup and view all the answers

Match the following phases of the ovarian cycle with their characteristics:

Follicular phase = Follicle develops and secretes estrogen Ovulation = Egg is released into the fallopian tube Luteal phase = Corpus luteum secretes progesterone and estrogen Signup and view all the answers

Study Notes

Exploitation Competition

Indirectly occurs when two species compete for the same limited resource.
An increase in one species' consumption leads to a decrease in resource availability for others, affecting their fitness.
Example: A surge in leopards reduces the warthog population, which also affects tigers that rely on warthogs for food.

Resource Partitioning

Different species coexist in the same habitat by utilizing different niches, minimizing direct competition.
Example: Two fish species occupy the same aquatic environment but live at varying depths to avoid competition for resources.

Apparent Competition

Represents an indirect competition where an increase in one species negatively impacts another species through a shared predator.
Example: Higher beetle populations can lead to more owls, resulting in a decrease of spider populations as owls consume them due to the increase in available prey.

Intraspecific Competition

Occurs when individuals within the same species compete for limited resources such as food or mates.
Example: Two basil plants in a small pot compete for water and nutrients during dry conditions, potentially hindering each other’s growth potential.

Key Takeaway

Exploitation competition results from resource consumption, while apparent competition arises from shared predation, illustrating the complex dynamics within ecological communities.

Overview of the Citric Acid Cycle

Also known as the Krebs cycle, essential for cellular respiration.
Occurs in the mitochondria, known as the powerhouses of cells.

Steps of the Cycle

Acetyl CoA combines with oxaloacetate to form citrate.
Citrate is converted to isocitrate, an isomerization step.
Isocitrate is oxidized and loses a carbon dioxide molecule, forming alpha-ketoglutarate.
Alpha-ketoglutarate undergoes further oxidation to produce succinyl CoA.
Succinyl CoA is converted to succinate, releasing energy.
Succinate is oxidized to fumarate, continuing the energy extraction process.
Fumarate is hydrated to form malate.
Malate is oxidized back to oxaloacetate, completing the cycle.

Products of the Cycle

Each turn of the cycle generates three molecules of NADH, crucial for energy production.
Also produces two molecules of carbon dioxide (CO2), a waste product of metabolism.
Yields one molecule of FADH2, another electron carrier.
Generates one molecule of ATP, the energy currency of the cell.

Importance of the Citric Acid Cycle

Acts as a central hub in cellular metabolism, connecting carbohydrate, fat, and protein metabolism.
Provides NADH and FADH2 for the electron transport chain, which is essential for ATP generation.
Plays a vital role in the overall energy metabolism of aerobic organisms.

Energy Investment Phase

Glucose: The starting point of glycolysis, a six-carbon sugar.
Hexokinase: An enzyme that catalyzes the phosphorylation of glucose, using ATP.
ATP to ADP: One ATP molecule is consumed, donating a phosphate group to glucose.
Glucose-6-phosphate: The product formed after phosphorylation, which is an important intermediate.
Isomerase: Catalyzes the conversion of glucose-6-phosphate to fructose-6-phosphate.
Fructose-6-phosphate: A six-carbon sugar phosphate that is rearranged for further processing.
Phosphofructokinase (PFK): Key regulatory enzyme that phosphorylates fructose-6-phosphate to fructose-1,6-bisphosphate using another ATP molecule.
ATP to ADP in PFK Reaction: Another ATP molecule is consumed, highlighting the energy investment.
Fructose-1,6-bisphosphate: The product that is formed, marking the end of the investment phase.

Energy Payoff Phase

Glyceraldehyde 3-phosphate (G3P): A three-carbon intermediate that undergoes oxidation.
NAD+ to NADH: G3P is oxidized, reducing NAD+ to NADH, which is a crucial step in energy production.
2 ADP to 2 ATP: Two molecules of ADP are phosphorylated to produce two ATP during substrate-level phosphorylation.
Pyruvate: Final product of glycolysis, which can enter the citric acid cycle under aerobic conditions or be converted to lactate under anaerobic conditions.

Cellular Respiration Overview

Glycolysis Location: Occurs in the cytoplasm of the cell.
Eukaryotic Process: Pyruvate and NADH produced during glycolysis are transported into the mitochondria for subsequent reactions.
Prokaryotic Process: Glycolysis, pyruvate manipulation, and the Krebs cycle take place in the cytosol, while the electron transport chain occurs at the cellular membrane.

Cellular Organelles and Their Functions

Golgi Apparatus: Involved in modifying and packaging proteins and lipids; sends products to various cell destinations via vesicles.
Nucleus: Houses and protects DNA; site for DNA replication and transcription in eukaryotes.
Cell Membrane: Participates in oxidative phosphorylation in prokaryotes.
Mitochondria: In eukaryotic cells, pyruvate manipulation and Krebs cycle occur in the mitochondrial matrix; the electron transport chain is located across the inner mitochondrial membrane.

Key Process Takeaway

Glycolysis is the first step in cellular respiration, initiated within the cytosol, leading to further metabolic pathways in mitochondria for eukaryotes and in the cytosol for prokaryotes.

Horizontal Gene Transfer

Horizontal gene transfer is a process where genetic material is exchanged between organisms, enhancing genetic diversity.

Conjugation

Involves the F plasmid, which is a circular DNA molecule that facilitates gene transfer.
The pilus is a specialized appendage that forms a connection between two bacterial cells.
Gene transfer occurs through a cytoplasmic bridge formed by the pilus, allowing direct DNA transfer from one bacterium to another.

Transformation

Some bacteria possess pores in their cell membranes that allow the uptake of external DNA.
Loose DNA fragments from the environment can be incorporated into a bacterial cell’s genome.
This process contributes to genetic variation and adaptability in bacterial populations.

Transduction

Involves bacteriophages (viruses that infect bacteria) that can carry bacterial DNA.
Viruses can pick up bacterial DNA from one host and transfer it to another during infection.
This method of gene transfer can lead to new traits being introduced into bacterial populations.

Stomach

When food enters the stomach, it triggers the release of pepsinogen.
Pepsinogen is converted to pepsin in the presence of hydrochloric acid (HCI).
Pepsin is an active enzyme that begins the digestion of proteins.

Small Intestine

Chyme, a semi-fluid mass of partially digested food, enters the small intestine.
This triggers the release of cholecystokinin, a hormone that stimulates pancreatic enzyme secretion.
The pancreas secretes trypsinogen and chymotrypsinogen, which are inactive precursors to proteolytic enzymes.

Activation of Proteases

Enteropeptidase, released by the small intestine, activates trypsin from trypsinogen.
Activated trypsin subsequently activates chymotrypsin from chymotrypsinogen.
These enzymes work together to further break down proteins into smaller peptides and amino acids.

Protein Breakdown Process

Proteins are initially broken down by proteases into smaller polypeptides and individual amino acids.
The digestion of proteins is a crucial process for nutrient absorption and utilization in the body.

Fat Absorption Process

The liver is essential for fat digestion as it produces bile, a crucial digestive fluid.
Bile is transported to the gallbladder, where it is concentrated and stored until needed.
Upon arrival of chyme in the small intestine, the duodenum releases cholecystokinin (CCK), triggering the gallbladder to release bile.
The released bile enters the duodenum, where it emulsifies fats, breaking them into smaller droplets to enhance digestion.
Lipases, enzymes produced by the pancreas, break down emulsified fats into fatty acids and glycerol for absorption.
The small intestine is the main site for fat absorption, utilizing the products of lipase digestion.

Cancer Causing Mutations

One-hit, gain-of-function mutations transform normal genes into oncogenes through a single mutation, leading to uncontrolled cell proliferation.
Proto-oncogenes are responsible for creating proteins that control the cell cycle; mutations can result in overproduction or hyperactivity of these proteins.
The one-hit, gain-of-function hypothesis means that only one mutated copy of a proto-oncogene is needed for it to become oncogenic.

Two-hit, loss-of-function mutations

The two-hit hypothesis involves two mutations that disable both copies of tumor suppressor genes, allowing for cancerous growth.
Tumor-suppressor genes help prevent excessive cell division; mutations resulting in their loss lead to the inability to regulate the cell cycle effectively.
These genes are haplosufficient, meaning a single functional copy is enough to suppress tumor formation.

Key Takeaway

Proto-oncogenes lead to cancer when a single gain-of-function mutation occurs.
Tumor-suppressor genes lead to cancer development only after both copies have undergone loss-of-function mutations.

Genomic Library (DNA Library)

A genomic library comprises the complete genomic DNA from one organism, serving as a resource for genetic research.

Generating a Genomic Library

Restriction enzymes are crucial for cutting the organism's genome into numerous overlapping DNA fragments.
DNA ligase plays a vital role by inserting cloned DNA fragments into plasmid vectors to facilitate cloning.
Bacteria take up the plasmids, allowing for gene expression and replication.
Screening methods, such as antibiotic resistance or color change, help identify bacteria that contain the desired gene.
Isolating specific bacteria enables cloning, leading to the amplification and analysis of targeted genes.

DNA Fingerprinting

A genetic identification method that distinguishes individuals based on unique DNA features.
Restriction Fragment Length Polymorphisms (RFLPs) generate distinct fragment patterns by cutting DNA with restriction enzymes at specific sequences.
Short Tandem Repeats (STRs) refer to repeating nucleotide sequences, with variations in lengths across individuals.
DNA from a suspect can be compared to evidence, such as blood samples, enabling forensic matching.

ELISA (Enzyme-Linked Immunosorbent Assay)

A diagnostic technique used to detect specific antigens within a sample.
Involves applying a sample to a test plate coated with antibodies that bind to the targeted antigen.
A color change in the test plate indicates the presence of the antigen, commonly used in disease diagnosis, including HIV.

SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis)

A gel electrophoresis technique designed to separate proteins based on size and charge, essential for protein analysis.

Key Takeaway

Genomic library creation encompasses DNA extraction, restriction enzyme cutting, insertion into plasmids, and bacterial cloning for analysis and amplification of genetic material.

Types of Photosynthesis in Plants

C3 plants primarily conduct photosynthesis in mesophyll cells using the Calvin cycle to produce glucose.
C4 plants utilize both mesophyll and bundle sheath cells, first creating a C4 intermediate that enhances CO2 fixation and ultimately leads to glucose production via the Calvin cycle.
CAM (Crassulacean Acid Metabolism) plants also use mesophyll cells and a C4 intermediate, performing the Calvin cycle to synthesize glucose.

Photorespiration

Photorespiration occurs when RuBisCo enzyme binds to oxygen instead of carbon dioxide, leading to the oxygenation of RuBP and disruption of the Calvin cycle.
This process can be detrimental as it reduces the efficiency of photosynthesis.

CAM Plants Adaptations

CAM plants have adapted to arid environments by utilizing temporal isolation, performing different processes at different times to minimize water loss.
During nighttime, cooler temperatures allow CAM plants to open their stomata, absorbing CO2 while minimizing transpiration.
To conserve water during the hot daytime, stomata remain closed, utilizing stored CO2 for photosynthesis in the Calvin cycle, thus reducing exposure to oxygen and limiting photorespiration.

Key Takeaway

CAM plants exemplify a strategy to endure hot, dry environments, where they close their stomata during the day and absorb CO2 at night, effectively balancing water conservation and photosynthesis.

Nondisjunction Overview

Nondisjunction refers to the failure of chromosomes to separate properly during cell division.
This error can lead to aneuploidy, an abnormal number of chromosomes in the resulting gametes.

Human Genome and Meiosis

The human genome consists of 46 chromosomes, organized into 23 homologous pairs.
During meiosis I, homologous chromosomes are separated into daughter cells.
Each daughter cell after meiosis I contains 23 chromosomes and 46 chromatids.

Nondisjunction in Meiosis

Nondisjunction may occur during meiosis I or meiosis II.
In meiosis I:
- Results in two daughter cells with n+1 (2n+1 after fertilization) and two with n-1 (2n-1 after fertilization).
In meiosis II:
- Results in one daughter cell with n+1 (2n+1), one with n-1 (2n-1), and two normal daughter cells with n (2n after fertilization).

Chromosome Outcomes

If nondisjunction occurs during meiosis I:
- Possible zygote chromosome counts after fertilization are 45 (2n-1) and 47 (2n+1).
Consequently, the potential chromosome numbers in the zygote are 45 or 47.

Key Takeaway

Nondisjunction can significantly affect genetic outcomes, leading to conditions such as Down syndrome (47 chromosomes) or Turner syndrome (45 chromosomes).

Germ Layers and Their Derivatives

Ectoderm (outermost germ layer) gives rise to:
- Central nervous system structures, including the brain and spinal cord
- Peripheral nerves and neural crest cells
- Sensory organs: ear, eye, and nose components
- Epidermis, nails, hair, mammary glands, and sweat glands
- Pigmentation cells and enamel of teeth
- Adrenal medulla
Mesoderm (middle germ layer) develops into:
- Bone structure and skeletal system
- All types of muscle tissue: skeletal, smooth, and cardiac
- Components of the cardiovascular (heart and blood vessels) and lymphatic systems
- Gonads (reproductive organs) and adrenal cortex
- Spleen and notochord, which is significant for spinal cord formation
Endoderm (innermost germ layer) forms:
- Lining of digestive, respiratory, and excretory tracts
- Organs including stomach, liver, pancreas, lungs, and bladder
- Endocrine glands such as thyroid, parathyroid, and thymus

Mnemonics for Recall

attracto-derm: Represents derivatives that attract relationships
means-oderm: Refers to derivatives providing movement capabilities
end-oderm: Indicates internal derivatives associated with organs like pancreas, liver, and the PLTT (bladder)

Hardy-Weinberg Equilibrium Overview

Hardy-Weinberg equilibrium applies to populations for allele frequencies of B (dominant) and b (recessive).
Homozygous recessive frequency (q²) is a given value, representing the proportion of individuals with the genotype bb.

Key Equations

Allele Frequency: p + q = 1
- p represents the frequency of the dominant allele (B)
- q represents the frequency of the recessive allele (b)
Genotype Frequency: p² + 2pq + q² = 1
- p² indicates the frequency of homozygous dominant individuals (BB)
- 2pq indicates the frequency of heterozygous individuals (Bb)
- q² indicates the frequency of homozygous recessive individuals (bb)

Calculating Allele Frequencies

Given that q² = 0.09 (9% of the population is homozygous recessive):
- Calculate q:
  - q = √(0.09) = 0.3
Determine p:
- p + q = 1
- p + 0.3 = 1
- p = 0.7

Frequency of Heterozygous Individuals

Using the values of p and q to find the heterozygous frequency (2pq):
- 2pq = 2(0.7)(0.3) = 2(0.21) = 0.42
- Hence, 42% of the population is heterozygous (Bb).

Key Takeaway

Hardy-Weinberg equilibrium maintains constant allele and genotype frequencies across generations under ideal conditions (no selection, mutation, migration, or genetic drift).
Helps in understanding genetic variation and population genetics dynamics.

Overview of Beta-Oxidation

Occurs in the mitochondrial matrix, responsible for breaking down fatty acids.
Reactants are fatty acids and coenzyme A (CoA).
Key products are acetyl-CoA, NADH, and FADH2.

Key Products

Acetyl-CoA: Formed from fatty acids, directly enters the citric acid cycle.
NADH and FADH2: Produced during the process, enter the electron transport chain for ATP production.

Misconceptions Clarified

NAD+ is a reactant, while NADH is a product of beta-oxidation.
Glucose Production: Fatty acids cannot be converted into glucose in humans and animals; they only yield acetyl-CoA.
Fatty Acids: Act as reactants in the process; they are not products of beta-oxidation.
Oxygen: Not a product of beta-oxidation; the term “oxidation” refers to electron removal from fatty acids.

Key Takeaway

Beta-oxidation is crucial for energy production, converting fatty acids into acetyl-CoA, enabling further energy extraction in the Krebs cycle, while producing vital electron carriers (NADH and FADH2).

Na+/K+ ATPase Function

Na+/K+ ATPase, or sodium-potassium pump, requires ATP for its activity.
Pumps three Na+ ions out of the cell and two K+ ions into the cell, against their concentration gradients.
Creates an electrochemical gradient critical for cell function.
External environment: high Na+ concentration, low K+ concentration.
Internal environment: low Na+ concentration, high K+ concentration.
Mnemonic: “Salty banana” helps remember the ion distribution.

Consequences of Pump Inactivation

If Na+/K+ ATPase cannot hydrolyze ATP:
- Na+ ions cannot be expelled from the cell.
- K+ ions cannot be taken into the cell.
Resulting ion distribution changes:
- Increased Na+ concentration inside the cell.
- Increased K+ concentration outside the cell.

Correct Answer Context

Among the provided options, the correct outcome is that Na+ would accumulate within the cell while K+ would increase outside the cell.
This reflects the disrupted function of the pump due to the lack of ATP hydrolysis.

General Characteristics of Arthropods

Invertebrate animals characterized by a hard external exoskeleton for support and protection.
Body is divided into segments, allowing for specialization of body parts.
Jointed appendages enable enhanced mobility and flexibility.
Triploblastic nature indicates three embryonic cell layers: ectoderm, mesoderm, and endoderm.
Bilateral symmetry ensures a symmetrical arrangement along a central axis.

Annelida (Segmented Worms)

Phylum consisting of segmented worms, including earthworms and leeches.
Lacks an exoskeleton yet features body segmentation, similar to arthropods and chordates.

Chordata (Animals with Notochord)

Phylum identified by the presence of a notochord during development, which provides skeletal support.
Four critical embryonic structures: notochord, hollow dorsal nerve cord, pharyngeal slits, and post-anal tail.
Exhibits body segmentation, despite the absence of an exoskeleton.

Echinodermata (Marine Invertebrates)

Phylum encompassing invertebrate marine animals like starfish, sea urchins, and sand dollars.
Adults display radial symmetry, which differs from the bilateral symmetry prevalent in arthropods and chordates.
Lacks both an exoskeleton and body segmentation.

Rotifera (Microscopic Zooplankton)

Phylum comprising aquatic, microscopic animals known as rotifers.
Absence of exoskeleton and body segmentation distinguishes them from other invertebrate groups.

Key Takeaway

Arthropods are unique for possessing exoskeletons and exhibiting body segmentation, setting them apart from other phyla like Annelida, Chordata, Echinodermata, and Rotifera.

Excretory System Filtration

Filtration occurs at the renal corpuscle, which consists of the glomerulus and Bowman's capsule.
Key structures involved are the afferent arteriole (brings blood in) and the efferent arteriole (takes blood out).

Nephron Processes Overview

Four primary processes in the nephron: filtration, reabsorption, secretion, and excretion.

Filtration Process

Involves the movement of fluids and solutes from blood into the renal tubules.
Essential for removing waste and excess substances from the bloodstream.

Reabsorption

Takes place mainly in the proximal convoluted tubule.
Key substances reabsorbed include glucose, amino acids, and salts (Na+).
Helps maintain electrolyte balance and retain important nutrients.

Secretion

Additional waste products and excess ions (like H+) are secreted from the blood into the renal tubules.
Important for regulating blood pH and eliminating toxic substances.

Excretion

The final elimination of waste products and excess water is through urine formation.
Urine is transported to the bladder for storage before excretion from the body.

Proximal Tubule Function

Primarily responsible for reabsorption and secretion.
Approximately 65% of the filtered water and sodium is reabsorbed here.

Distal Tubule and Collecting Duct

The distal tubule reabsorbs sodium (Na+), chloride (Cl-), and water, while secreting hydrogen (H+) and potassium (K+).
The collecting duct is responsible for final water reabsorption and urine concentration before excretion.

Loop of Henle Structure

Comprised of ascending and descending limbs.
Ascending limb reabsorbs solutes, making the filtrate more dilute, while descending limb reabsorbs water.

Importance of Each Process

Each nephron process plays a crucial role in homeostasis, maintaining fluid balance, electrolyte levels, and waste elimination.

Ovarian Cycle Phases

Comprises three distinct phases: follicular, ovulation, and luteal.
Follicular phase: Follicle matures, secretes increasing estrogen, leading to a surge in luteinizing hormone (LH).
Ovulation: Release of a secondary oocyte into the oviduct occurs as the mature follicle ruptures.
Luteal phase: Corpus luteum forms from the follicle and secretes estrogen and progesterone, necessary for thickening the endometrium.

Accurate Statements About the Luteal Phase

Development of the corpus luteum from the follicle is the hallmark of the luteal phase.
Estrogen and progesterone secreted by the corpus luteum prepare the endometrium for potential implantation of an embryo.

Misconceptions During the Luteal Phase

Secondary oocyte release occurs during ovulation, not the luteal phase.
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) peak during the follicular phase, leading up to ovulation.
Primary follicles mature into secondary follicles during the follicular phase due to stimulation by FSH.

Hormone Levels

FSH and LH levels peak in the follicular phase, with LH exhibiting a sharp peak at ovulation.
Estrogen levels rise during the follicular phase, with a peak just prior to ovulation.
Progesterone levels rise in the luteal phase, contributing to endometrial thickening.

Uterine Cycle Changes

The endometrium thickens during the proliferative phase (follicular phase).
The endometrium becomes receptive for implantation during the secretory phase (luteal phase).
Menstruation marks the shedding of the endometrium, initiating a new cycle.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your understanding of ecological concepts with this quiz focusing on exploitation and apparent competition. Explore how species compete for resources and the impact of population changes, such as the case of leopards and tigers competing for warthogs.

Mixed Review

Choose a study mode

Podcast

Questions and Answers

What type of competition occurs when two species indirectly compete for the same limited resource?

Resource partitioning allows different species to coexist by occupying the same niche.

What is the term for indirect competition caused by a shared predator?

Intraspecific competition occurs when members of the same __________ compete for limited resources.

Match the following types of competition with their definitions:

What is the main function of the citric acid cycle?

The citric acid cycle occurs in the nucleus of the cell.

Name one product generated from each cycle of the citric acid cycle.

The citric acid cycle begins with the combination of acetyl CoA and __________.

Match the steps of the citric acid cycle with their corresponding outputs:

What is the first substrate used in glycolysis?

In the energy payoff phase of glycolysis, 4 ATP molecules are produced.

What enzyme converts fructose-6-phosphate to fructose-1,6-bisphosphate?

Glyceraldehyde 3-phosphate (G3P) is converted to __________ during glycolysis.

Match the following components of glycolysis with their functions:

Where does glycolysis occur within a cell?

In prokaryotes, the electron transport chain occurs in the mitochondria.

What molecule is produced from glycolysis that is subsequently used in the Krebs cycle?

Glycolysis is the first step in the process of __________.

Match the following cell components with their functions in cellular respiration:

What is the role of the pilus in conjugation?

Transformation involves the uptake of DNA by bacteria with no specialized structures.

What type of genetic material is exchanged during transduction?

In transformation, bacteria incorporate __________ DNA.

Match the type of horizontal gene transfer with its description:

What enzyme is activated from pepsinogen in the stomach?

Cholecystokinin is released in the stomach to help with protein digestion.

What is the primary function of enteropeptidase in protein digestion?

The process of protein digestion begins with proteins being broken down by __________.

Match the following enzymes with their role in protein digestion:

What stimulates the gallbladder to release bile?

The liver directly absorbs fats after producing bile.

What happens to large fat globules in the small intestine?

The __________ concentrates and stores bile produced by the liver.

Match the following steps in fat absorption with their descriptions:

What type of mutation leads to the formation of an oncogene?

Tumor-suppressor genes require a single mutation to cause cancer.

What is the key difference between proto-oncogenes and tumor-suppressor genes in relation to cancer?

A __________ mutation in both copies of tumor-suppressor genes leads to cancerous proliferation.

Match the type of mutation with their corresponding effects:

What is the main function of a genomic library?

Restriction fragment length polymorphisms (RFLPs) are used in DNA fingerprinting.

Name one method used to screen bacteria for a gene of interest.

In SDS-PAGE, proteins are separated based on their ________ and ________.

Match the following techniques with their purposes:

What process occurs when RuBisCo binds to oxygen instead of carbon dioxide?

CAM plants open their stomata during the day to absorb CO2.

What is the primary advantage of CAM photosynthesis in desert plants?

In C4 plants, the carbon dioxide is first fixed by the __________ in the mesophyll cells.

Match the types of plants with their photosynthetic characteristics:

What happens to the number of chromosomes in a zygote if nondisjunction occurs during meiosis I?

Nondisjunction can only happen during meiosis I.

What is the term used to describe the condition of having an abnormal number of chromosomes?

If nondisjunction occurs during meiosis I, the resulting gametes can have either n+1 or n-1 chromosomes, which translates to __________ or __________ chromosomes after fertilization.

Match the terms related to nondisjunction with their definitions:

Which structure is developed from the ectoderm?

The mesoderm gives rise to the lining of the digestive system.

What does the mnemonic 'means-oderm' help to remember?

The _____ develops into the central nervous system.

Match the following germ layers with their derived structures:

What is the percentage of the population that is heterozygous for the allele?

In Hardy-Weinberg equilibrium, q2 represents the frequency of homozygous dominant individuals.

What do the symbols p and q represent in the equation p + q = 1?

The frequency of homozygous recessive individuals in the population is represented by ________.

Match the following equations with their meanings:

What is one of the products formed during beta-oxidation?

NADH is produced as a result of beta-oxidation.

Where does beta-oxidation occur within a cell?

In beta-oxidation, fatty acids are converted into ________.

Match the substances to their roles in beta-oxidation:

What is the primary function of the Na+/K+ ATPase?

Na+/K+ ATPase hydrolyzes ATP to pump ions against their concentration gradients.

How many Na+ ions does the Na+/K+ ATPase pump out of the cell?

If the Na+/K+ ATPase cannot hydrolyze ATP, Na+ will concentrate ______ the cell and K+ will concentrate ______ the cell.

Match the following ion movements with their corresponding concentrations when the Na+/K+ ATPase is inactive:

Which characteristic is NOT associated with arthropods?

In SDS-PAGE, proteins are separated based on their and .

If nondisjunction occurs during meiosis I, the resulting gametes can have either n+1 or n-1 chromosomes, which translates to or chromosomes after fertilization.

If the Na+/K+ ATPase cannot hydrolyze ATP, Na+ will concentrate the cell and K+ will concentrate the cell.