Biology unit 1 Exam

What’s a DV (dependent variable)

the variable that will (or may) change because you changed the independent variable

What’s a IV (independent variable)

The variable that your changing in order to test the effect

What’s the purpose of a CV (control variable)

to ensure that only the independent variable can be causing a change in the dependent variable

increases validity of the experiment

What is a controlled variable

factor in an experiment that is kept constant to ensure that the results are reliable and accurate

What’s precision

How close all the data is to each other

What’s accuracy

How close the data is to the true value

What’s validity

how well an experiment or investigation actually measures what it is supposed to measure

Difference between quantitative and qualitative data

‘Quali(ty)’tative- describing

‘Quan(tity)’titative- numbers, data

What information needs to be included in a hypothesis?

How you expect the IV to affect the DV

including the direction of change

Advantages of larger surface area to volume ratio (SA:V)

Faster diffusion rates

allows cells and organisms to exchange nutrients, gases, and waste products with their environment more efficiently

Does SA:V affect rate of diffusion or efficiency?

yes, lower SA:V means it will take longer for nutrients or waste to absorb therefore being less efficient

When a cell grows, does the SA:V increase?

no, it decreases because volume of the cell increases faster than its surface area

What is surface area to volume ration a measure of?

compares the surface area of an object to its volume]rsr

Prokaryote cell features

Lack membrane-bound organelles

has no nucleus

Eukaryote cell features

membrane-bound nucleus & organelles

bigger than prokaryotic cells

What’s the function of the Nucleus

To contain most of the genetic material (DNA) of the cell

regulates protein synthesis and cell division

What’s the function of the Endoplasmic reticulum

To transport materials such as proteins and lipids

What’s the function of the Golgi body

Modifies and packages proteins to be exported from the cell

What’s the function of ribosomes

read the genetic code from mRNA

What’s the function of chloroplast

site of photosynthesis in plant cells

contain chlorophyll

What’s the function of the mitochondria

to do aerobic respiration

What’s the function of large vacuoles

to help plant maintain its structure with turgor (swelling) pressure

stores metabolic wastes from the cell

What’s the structure of the Nucleus

surrounded by a nuclear envelope that has two layers of membrane

pierced with nuclear pores

What’s the structure of the Endoplasmic reticulum

network of membrane channels

What’s the structure of the Golgi body

stack of hlattened membrane-bound sacs

What’s the structure of ribosomes

not membrane bound

made of 60% rRNA and 40% protein

What’s the structure of chloroplast

bound by two layers of membrane

smaller structures called thylakoids, each membrane-bound

thylakoids stacked are grana

What’s the structure of the mitochondria

double membrane-bound

What’s the structure of large vacuoles

membrane bound sac

What’s anaerobic respiration

metabolic process that generates energy (ATP) in the absence of oxygen

What’s aerobic respiration

metabolic process that utilizes oxygen to convert glucose into energy (ATP), carbon dioxide, and water

What’s the equation for anaerobic respiration

Glucose → Lactic Acid + Energy (ATP)

What’s the equation for aerobic respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)

What’s the purpose of aerobic respiration

produce energy in the form of ATP for cells to use

What’s the purpose of an aerobic respiration

provide energy in the absence of oxygen, allows glycolysis to continue producing ATP

What are the limiting factors of aerobic respiration

oxygen concentration, glucose concentration, and temperature. influence the efficiency and speed of biochemical reactions in breaking down glucose to produce energy

What are the limiting factors of anaerobic respiration

oxygen deficiency

Examples of anaerobic respiration

alcohol fermentation, lactic acid fermentation and in decomposition of organic matter

Examples of aerobic respiration

Krebs cycle

Chemical equation for photosynthesis

What do plant cells look like

What do animal cells look like

What’s diffusion

molecules dispersing between a membrane until they have reaches equilibrium

What’s osmosis

passive net movement of free water molecules through a semi permeable membrane

What’s a hypertonic solution

having a higher osmolality (concentration of solutes) than the extracellular fluid

What’s a hypotonic solution

having a lower osmolality (concentration of solutes) than the extracellular fluid

What’s an isotonic solution

having the same osmotic pressure as the extracellular fluid

What’s passive transport (Include examples)

transport though the membrane that doesn’t require energy

e.g oxygen, carbon dioxide, salts, ethanol

What’s facilitated diffusion (Include examples)

transport through the cells that requires energy

e.g transport of glucose, amino acids, and ions

What’s endocytosis

cell takes in substances from its surrounding environment by forming a vesicle

essentially "eating" the external material

type of active transport that requires energy

What’s exocytosis

substances are released from inside a cell to the external environment

What’s a hydrophobic molecule

repels or doesn't mix well with water

e.g flour

What’s a hydrophilic molecule

one that readily dissolves in water or other polar solvents

What are polar molecules

molecules that have a separation of electric charge

one end of molecule slightly positive and the other end slightly negative

water, ethanol, ammonia

What are non-polar molecules (Include example)

molecules that lack an overall electric charge

co2, methane, most molecules containing carbon

What’s the function of the plasma membrane

act as a barrier, separating the cell's internal environment from the external one

role in regulating the movement of substances into and out of the cell

Diagram of the plasma membrane

Parts of the plasma membrane

phosphate head

fatty acid tails

carbohydrate chains

glycoprotein

transport proteins

Difference between simple diffusion, facilitated diffusion and active transport

Simple diffusion involves small, nonpolar molecules moving directly through the lipid bilayer

Facilitated diffusion uses membrane proteins to aid the movement of molecules down their concentration gradient, doesn't require energy

Active transport moves molecules against their concentration gradient, requiring energy and specific membrane proteins

Difference between eukaryote and prokaryotic cells

presence of a nucleus and membrane-bound organelles

What are unipotent cells

a specialized stem cell that can only differentiate into one type of cell

e.g Epidermal stem cells, Muscle stem cells

What are pluripotent cells

embryonic stem cell that can differentiate into any cell type found within the three primary germ layers of the body

ectoderm - skin, nervous system

mesoderm - muscle, bone, blood, urogenital

endoderm - lungs, gastrointestinal

What order to stem cells develop in

TPMOU Toti-pluri-multi-oli-uni

What are multipotent cells

The ability of a stem cell to differentiate into multiple, but limited, cell types within a specific lineage. 

e.g blood stem cells, capable of giving rise to all blood cell types, red blood cells, white blood cells, platelets

What are totipotent cells

capable of developing into any cell type in a complete organism, including both embryonic and extra-embryonic tissues (like the placenta)

How do uni-, pluri-, multi-, toti- potent cells differ from each other

toti- can give rise to all cell types in the embryo and extra-embryonic tissue

pluri- can differentiate into all cell types within the three germ layers (ectoderm, mesoderm, endoderm) but not extra-embryonic tissues. 

multi-can differentiate into multiple cell types within their specific lineage

toti-can only differentiate into a single cell type

Difference between binary fission and mitosis

Binary fission is the primary method of cell division in prokaryotes, while mitosis is the primary method in eukaryotic cells

Phases of the eukaryotic cell cycle

mitosis (PMAT)

interphase (cytokenesis, G1, Synthesis, G2)

= 2 daughter cells

Where do checkpoints appear in mitosis

Metaphase - chromosome spindle attachment

G₁ - Nutrients, growth factors, DNA damage

G₂

What type of errors do checkpoints look for in mitosis and how do they fix the errors

DNA damage, incomplete DNA replication, or chromosomes not properly attached to the spindle.

fix errors by pausing the cell cycle to allow repair

if the problem can't be fixed, the cell will self-destruct through apoptosis

What is apoptosis?

programmed cell death

What is Necrosis?

uncontrolled cell death

How are living things organized?

Cell, tissue, organ, system, organism

What are the systems in the body?

skeletal

muscular

nervous

endocrine

respiratory

digestive

urinary

reproductive

What organs are in the digestive system

mouth

esophagus

stomach

small intestine

large intestine

rectum

liver

gallbladder

pancreas

What’s the function of the digestive system

break down food into smaller molecules that the body can absorb and use for energy, growth, and repair

What organs are in the excretory system

kidneys

ureters

bladder

urethra

What’s the function of the excretory system

eliminate waste products and excess fluids from the body maintaining homeostasis

What’s the difference between mechanical and chemical digestion

Mechanical digestion involves physically breaking down food into smaller pieces without altering its chemical composition

Chemical digestion uses enzymes and other chemicals to chemically break down food into smaller molecules. 

What’s mechanical digestion

physical breakdown of food into smaller pieces without altering its chemical composition

What’s chemical digestion

enzymes break down large food molecules into smaller, absorbable components. This process occurs in the digestive tract

Examples of mechanical digestion

chewing, churning in the stomach

Examples of chemical digestion

protein/fat digestion, nucleic acid digestion

What organs are in the endocrine system

hypothalamus

pituitary gland

thyroid gland

pancreas

What’s the function of the endocrine system

regulate and coordinate various bodily functions through the secretion of hormones

What’s the structure of Xylem

What’s the function of Xylem

transport water and dissolved minerals from the roots to the rest of the plant, including the stems and leaves

What’s the structure of Phloem

What’s the function of Phloem

to transport sugars and other organic molecules throughout a plant

Describe water movement into roots

happens through osmosis

Water moves from areas of higher water potential (like the soil) to areas of lower water potential (inside the root cells)

Describe water movement into stems

facilitated by the specialized xylem tissue, which acts like a network of tiny tubes extending from the roots up the stem and into the leaves

Describe water movement into leaves

transpiration

What’s a cell

smallest unit capable of carrying out all the functions of life

What’s a tissue

group of similar cells and their surrounding matrix, working together to perform a specific function

What’s an organ

a collection of tissues that structurally form a functional unit specialized to perform a particular function

What’s a system

related components-such as organs, tissues, cells, or molecules-that interact and work together as a unified whole to perform specific biological functions

What’s homeostasis?

body's ability to maintain a stable internal environment despite changes in external conditions

e.g body temperature, blood sugar levels, and fluid balance

What’s osmoregulation?

regulates the balance of water and electrolytes (like salt) within its body fluids to maintain a stable osmotic pressure

What’s the stimulus response model?

How is high body temperature regulated?

STIMULUS: body temperature reises above 37 degrees

RECEPTOR: Increase detected by thermoreceptors in skin, organs & hypothalamus

CONTROL CENTER: Hypothalamus sends signals via nerve and hormones to effectors

EFFECTORS: sweat glands, blood vessels in skin, cerebral cortex, body cells

RESPONSE: increase in swelling, vasodilation of skin vessels, behavioral cortex, decreased metabolic rate