Bio Exam revision

The Nucleus controls

The Nucleus controls

the cell's activities and stores genetic information (DNA).

mitochondria produce

energy (ATP) through cellular respiration.

chloroplasts are the:

Site of photosynthesis, where light energy is converted into chemical energy (glucose).

the rough endoplasmic reticulum (RER) is involved in?

the synthesis, folding, and modification of proteins.

the smooth endoplasmic reticulum (SER) sythesizes

lipids, detoxifies harmful substances, and regulates calcium levels in the cell.

the Golgi apparatus modifes

sorts, and packages proteins and lipids for transport to specific destinations.

lysosomes contain

enzymes to break down and recycle cellular waste materials and foreign substances.

vacuoles store

water, nutrients, and waste materials; provides structural support in plant cells.

ribosomes are reponsible for

protein synthesis.

the cell wall provides

structural support, protection, and shape to the cell.

the plasma membrane controls

the movement of substances in and out of the cell and maintains cell integrity.

the nucleolus produces

ribosomes, which are essential for protein synthesis.

What happens in prophase?

Chromatin condenses into visible chromosomes, Nuclear envelope disintegrates, Spindle fibers form.

What happens in metaphase?

Chromosomes align along the equatorial plane (metaphase plate) of the cell, Spindle fibers attach to the centromeres of the chromosomes.

What happens in anaphase?

Sister chromatids separate and move towards opposite poles of the cell, Spindle fibers shorten, pulling the chromatids apart.

What happens in telophase?

Chromosomes reach the opposite poles of the cell, Nuclear envelopes reform around each set of chromosomes, Chromosomes begin to decondense.

What happens in cytokinesis?

Division of the cytoplasm occurs, Two daughter cells are formed, each with a complete set of chromosomes and organelles.

What is the phospholipid bilayer?

The double layer of phospholipid molecules that forms the basic structure of the cell membrane.

What is the composition of the phospholipid bilayer?

Primarily composed of phospholipids, with hydrophilic heads and hydrophobic tails.

How do phospholipids arrange themselves in the bilayer?

Phospholipids orient themselves with the hydrophilic heads facing outward and the hydrophobic tails facing inward, forming the bilayer structure.

What is the function of the phospholipid bilayer?

Acts as a selectively permeable barrier, controlling the movement of substances into and out of the cell.

What role does the phospholipid bilayer play in maintaining cell integrity?

Provides structural support and helps maintain the shape of the cell.

How does the phospholipid bilayer interact with other molecules?

Accommodates the insertion of proteins, cholesterol, and other molecules within the membrane, contributing to its functionality.

What is the significance of the fluidity of the phospholipid bilayer?

Allows for the lateral movement of molecules, facilitating various cellular processes.

What is Passive Transport?

How do molecules or ions move across a cellular membrane without the need for energy input from the cell?

What is Active Transport?

Process by which cells move molecules across a membrane from an area of low concentration to an area of high concentration, using energy in the form of ATP.

What is Channel meditated diffusion

Process in which ions or molecules move across a cell membrane through a specific protein channel. The channel provides a pathway for the substance to move down its concentration gradient, without the need for energy.

What is Carrier meditated diffusion

Process where a molecule binds to a specific protein (carrier) on the cell membrane, which then changes shape to transport the molecule across the membrane.

What is Endocytosis?

Process by which cells take in substances from outside the cell by engulfing them in a vesicle formed from the plasma membrane.

What is Exocytosis?

Process by which cells release molecules by fusing vesicles with the plasma membrane, allowing their contents to be released outside the cell.

What is Facilitated Diffusion?

Type: Passive Transport Definition: Movement of molecules across the cell membrane from high to low concentration with the help of transport proteins.

What is Osmosis?

The movement of water molecules from an area of high concentration to an area of low concentration across a selectively permeable membrane is called osmosis.

What is Diffusion?

The movement of particles from an area of high concentration to an area of low concentration, until equilibrium is reached.

What happens during G1 phase?

During G1 phase, the cell grows, replicates organelles, and synthesizes RNA and proteins needed for DNA replication. It is a period of intense metabolic activity and cellular growth in preparation for DNA synthesis in the S phase.

What happens during S phase?

S phase is the stage of the cell cycle where DNA replication occurs, resulting in the formation of two identical copies of each chromosome. It is a critical step in cell division and ensures that each daughter cell receives a complete set of genetic information.

What happens during G2 phase?

During G2 phase, the cell checks for DNA damage and prepares for cell division by synthesizing proteins and organelles necessary for mitosis.

What is the purpose of G1 phase?

Phase of the cell cycle where cells grow and prepare for DNA replication. It's a checkpoint for the cell to ensure that it's ready to move on to the next phase.

What is the purpose of S phase?

Purpose of S phase: DNA replication occurs during S phase of cell cycle. The purpose of S phase is to ensure that each daughter cell receives a complete and identical copy of genetic material.

What is the purpose of G2 phase?

G2 phase provides an opportunity for the cell to grow further, synthesize necessary proteins, and check for any DNA damage or errors before proceeding to mitosis.

What is the purpose of xylem?

Xylem transports water, minerals, and nutrients from the roots to the rest of the plant.

What is the purpose of phloem?

Phloem transports sugars, organic compounds, and other nutrients from the leaves to other parts of the plant.

What is the structure of xylem?

Xylem consists of tracheids and vessel elements, which are long, hollow cells that are dead at maturity and form interconnected tubes.

What is the structure of phloem?

Phloem is composed of sieve tube elements and companion cells. Sieve tube elements form the main conducting cells, and companion cells provide metabolic support.

What is the main difference between xylem and phloem in terms of transport direction?

Xylem transports materials in one direction, from the roots to the shoots, while phloem transports materials bidirectionally, both upward and downward in the plant.

What is the main difference between xylem and phloem in terms of transported substances?

Xylem primarily transports water and minerals, while phloem transports organic compounds, such as sugars and amino acids.

What is the main difference between xylem and phloem in terms of cell types?

Xylem is composed of dead cells at maturity, whereas phloem contains living cells.

What is the main difference between xylem and phloem in terms of cell structure?

Xylem cells are elongated and have thick cell walls for strength, while phloem cells have sieve plates or sieve areas that facilitate the movement of substances.

What is the intrinsic pathway to apoptosis?

It is an internal pathway initiated by cellular stress or damage.

What is the extrinsic pathway to apoptosis?

It is an external pathway triggered by death ligands binding to specific cell surface receptors.

What is the purpose of apoptosis?

Apoptosis serves several important purposes: Development: It helps shape and sculpt tissues and organs during embryonic development. omeostasis: It maintains a balance by eliminating damaged, infected, or unwanted cells. Immune Response: It removes immune cells that are no longer needed or potentially harmful.

Step 1 of apoptosis: What happens to the cell during this step?

The cell shrinks, loses contact with neighboring cells, and the chromatin condenses and begins to degrade.

Step 2 of apoptosis: What happens to the cell during this step?

The nuclear membrane degrades, the cell loses volume, and the chromatin clumps into chromatin bodies.

Step 3 of apoptosis: What is the process called during this step?

Zeiosis: The plasma membrane forms bubble like blebs on its surface.

Step 4 of apoptosis: What happens to the cell's nucleus and organelles during this step?

The nucleus collapses, but many membrane bound organelles are unaffected

Step 5 of apoptosis: What happens to the nucleus and DNA during this step?

The nucleus breaks up into spheres, and the DNA fragments into small fragments.

Step 6 of apoptosis: What happens to the cell during this step, and how are the apoptotic bodies removed?

The cell breaks into apoptotic bodies containing densely packed organelles, and these bodies are resorbed by phagocytosis.

In TPMOU, what does T stand for?

Totipotent

In TPMOU, what does P stand for?

Pluripotent

In TPMOU, what does M stand for?

Multipotent

In TPMOU, what does O stand for?

Oligopotent

In TPMOU, what does U stand for?

Unipotent

What can totioptent cells differntiate into?

Totipotent stem cells can differentiate into any cell type

What can pluripotent cells differntiate into?

Pluripotent stem cells can differentiate into any cell type of the three primary germ layers

What can multipotent cells differntiate into?

Multipotent stem cells can differentiate into multiple cell types within a specific lineage or tissue

What can oligopotent cells differntiate into?

Oligopotent stem cells can differentiate into a few closely related cell types within a specific lineage or tissue

What can unipotent cells differntiate into?

Unipotent stem cells can differentiate into only one specific cell type

What is the ectoderm?

outermost germ layer

What is the mesoderm?

middle germ layer

What is the endoderm?

innermost germ layer

What is the chemical level of organization?

Level of organization involving atoms and molecules, forming the foundation of life.

What is the organelle level of organization?

Organelle level involves specialized structures within cells that perform specific functions, such as the nucleus, mitochondria, and ribosomes.

What is the cellular level of organization?

The cellular level involves individual cells, which are the smallest functional units of life, capable of carrying out specific functions and maintaining homeostasis.

What is the organ level of organization?

The organ level involves groups of tissues working together to perform a specific function, forming organs such as the heart, liver, and lungs.

What is the organ system level of organization?

The organ system level involves multiple organs working together to perform a particular physiological function, such as the cardiovascular system, respiratory system, or digestive system.

What is the hierarchy of organization?

The hierarchy of organization refers to the sequential arrangement of levels, starting from the chemical level, progressing through the organelle, cellular, tissue, organ, and organ system levels, culminating in the complete organism.

What are endocrine glands?

Endocrine glands are specialized organs that produce and secrete hormones directly into the bloodstream

What are exocrine glands?

Exocrine glands are spcialized organs that produce and secrete hormones into the body through ducts

Give examples of endocrine glands.

Examples of endocrine glands include the pituitary gland, thyroid gland, adrenal glands, pancreas, ovaries, and testes.

Give examples of exocrine glands.

Examples of exocrine glands include salivary glands, sweat glands, sebaceous glands, mammary glands, and digestive glands (such as the pancreas and liver).

What are steroid hormones?

Hydrophobic Hormones made of lipid that bind to receptors inside cell

What are peptide hormones?

Hydrophillic Hormones made of proteins that bind to receptors outside cell

What is signal transduction?

Transduction is the process where relay molecules (chemical messengers) are used to simulate a change in cell function

What is transpiration pull?

Transpiration pull is the process by which water is pulled upward through the xylem due to the evaporation of water from the leaf surfaces. This creates a negative pressure, or tension, which pulls water molecules upward in the xylem.

How does cohesion contribute to water movement in the xylem?

Cohesion refers to the attractive forces between water molecules. In the xylem, water molecules are connected through cohesion, forming a continuous column. As water evaporates from the leaf surfaces, the tension created is transmitted down the water column, pulling more water molecules upward.

How does adhesion assist in water movement in the xylem?

Adhesion refers to the attraction between water molecules and the xylem vessel walls. Adhesion helps counter the force of gravity and prevents the water column from breaking as water is pulled upward.

What is root pressure?

Root pressure is the upward force exerted by the roots, resulting in the movement of water from the soil into the roots. It is primarily driven by active transport of mineral ions into the root cells, creating osmotic pressure that pushes water up the xylem.

What is the excretory system responsible for?

The excretory system is responsible for removing waste products, toxins, and excess substances from the body to maintain homeostasis.

What are the major organs of the excretory system?

The major organs of the excretory system include the kidneys, urinary bladder, ureters, and urethra.

What is the main function of the kidneys?

The main function of the kidneys is to filter blood and remove waste products, excess water, and electrolytes to form urine.

What is the urinary bladder?

The urinary bladder is a muscular sac that temporarily stores urine until it is expelled from the body during urination.

What are the ureters?

The ureters are narrow tubes that transport urine from the kidneys to the urinary bladder.

What is the urethra?

The urethra is a tube that carries urine from the urinary bladder to the outside of the body during urination.

What are the main components of a nephron?

A nephron consists of a renal corpuscle (composed of a glomerulus and Bowman's capsule) and a renal tubule (composed of proximal convoluted tubule, loop of Henle, and distal convoluted tubule).

What is a nephron?

the functional unit of the kidney, responsible for filtering the blood and forming urine.

What is the loop of Henle?

a U-shaped portion of the nephron in the kidney that plays a vital role in the concentration of urine by creating a concentration gradient in the renal medulla.

What is the digestive system?

The digestive system is a group of organs and glands that work together to process food, extract nutrients, and eliminate waste from the body.

What are the main organs of the digestive system?

The main organs of the digestive system include the mouth, esophagus, stomach, small intestine, large intestine, liver, gallbladder, and pancreas.

What is the function of the mouth in the digestive system?

The mouth is responsible for chewing and breaking down food into smaller pieces, and it also begins the process of digestion through the secretion of saliva.

What is the function of the esophagus?

The esophagus is a muscular tube that transports food from the mouth to the stomach using peristaltic contractions.

What is the function of the stomach?

The stomach receives food from the esophagus and mixes it with digestive enzymes and acids to break down proteins and begin the process of chemical digestion.