Studied by 22 people
What are the 7 food groups who represent large chemicals?
Fats
Proteins
Minerals
Vitamins
Carbohydrates
Water
Fibre
Which molecules in food produce energy?
One example is carbohydrates. Carbohydrates are made of long chains of identical small sugar molecules.
What is the digestive system?
an organ system (it works together)
What is the digestive system made of?
It is made of these organs that all work together:
Mouth
Gullet
Stomach
Liver
Pancreas
Large intestine
Small intestine
Rectum
Anus
What happens to the food in our body?
It is digested (which means it is broken down).
Which ways is the food digested?
Digestion happens in 2 ways:
Physical digestion
Chemical digestion
Chemical digestion:
This allows useful chemicals to be released and dissolved in the blood. To be broken down chemically, the bonds must be broken.
Physical digestion:
The shape of the food must be physically changed so that it can fit through the small diameter of the digestive system.
Where does the food enter our digestive tract?
Through the mouth.
Where does all the food leave the digestive tract?
Through the anus.
How long can the digestive system stretch?
It stretches out to a 9m tube!
How does a 9m tube fit into a space that is less than a metre long?
It is extremely folded! In addition, the tube passes through organs on its route from the mouth to the anus.
Fun fact!
There is 3 metres of DNA in every one of our cells!!
Aerobic respiration definition :
The form of respiration that uses oxygen.
Anaerobic respiration definition:
The form of respiration that does not use oxygen.
Anaerobic respiration equation:
Glucose → carbon dioxide + ethanol/lactic acid
Aerobic respiration equation:
Glucose + Oxygen → Carbon Dioxide + Water (+ Energy)
What are the 2 types of anaerobic respiration?
Humans and yeast
What is the equation for anaerobic respiration in humans?
Glucose = lactic acid + (very little) energy
What are the effects of long periods of vigorous exercise on the body?
Oxygen dept, heat produced
What is oxygen dept?
Temporary oxygen shortage after exercise.
What happens when a lot of heat is produced during exercise?
Lactic acid forms
What is the word equation for photosynthesis?
Carbon Dioxide + Water → Glucose + Oxygen
What is the balanced symbol equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What are the limiting factors of photosynthesis?
carbon dioxide, light, temperature
What is the name of anaerobic respiration in yeast?
Fermentation
What does homozygous mean?
When someone has 2 of the same alleles (recessive or dominant)
What does heterozygous mean?
A pair of genes 1 dominant 1 recessive
Phenotype:
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Genotype:
the genetic constitution of an individual organism.
How do you know if a baby will be female?
If there is no Y chromosome
Why is half of the world's population male and the other female?
because there is a 50% chance of a baby being a male or female when the egg is fertilized with a sperm. Half of the sperms carry X and the other carry Y. If the sperm fertilizing the egg is carrying an X then the baby will be a female. If it is carrying a Y, the baby will be male.
What is the gender of a baby with XX chromosomes?
Female
What is the gender of a baby with XY chromosomes?
Male
What is the word equation for photosynthesis?
Carbon dioxide + water → sunlight → oxygen + glucose
What is the test for Carbon Dioxide?
lime water test
What is a fossil?
The stone remains of animals or plants that were once alive.
What is the test for water?
breathing on something cold to get condensation
What are the 4 types of fossils?
Mold and cast, sediment, ice and amber
Example of mold and cast:
When the bones are casted into new stones.
Example of sediment:
when the bones decompose and an imprint of where they were is made/found.
What is mitosis?
A type of cell division that results in 2 daughter cells with the same amount and kind as the parent cell.
In order, what are the steps of mitosis?
Prophase, metaphase, anaphase, telophase, cytokinesis
What is meiosis?
A type of cell division that results in 4 daughter cells with half the amount of chromosomes in the parent cell.
Example of amber:
when mosquitoes get trapped in tree sap, it hardens and then melts long after.
Example of ice:
when Mammoths walked from one end of the Ice Age to another and they are frozen. They are then covered with more ice and snow until everything melts.
Why were Charles Darwin's finches so different?
because of their different habitats. They ate different things since there were different things available in their habitat. Number 1 ate big nuts and big fruits. 2 ate fruits and small nuts. 3 ate insects. Lastly 4 ate seeds.
How are there variations in species for humans?
Mutations, cross overs, independent assortment of chromosomes
How many chromosomes does a human have?
46
How many chromosomes do you get from each parent?
23
What is thermoregulation?
Maintaining a regular temperature in your body.
What is vasodilation?
When the blood vessels dilate (become wider) decreasing blood pressure.
What is vasoconstriction?
The constriction of blood vessels, increasing blood pressure.
What is the definition of homeostasis?
Maintaining a constant internal environment of the body. Hormones and the nervous system are the ones that oversee the conditions.
What does hypothalamus mean?
A region of the brain which control the homeostatic systems.
What is the definition of effector?
Organ or cell that acts in response to a stimulus.
What are capillaries?
The smallest of blood vessels which bring blood transporting oxygen to the tissues of the body and transport non-oxygenated blood from the tissues to the veins and arteries.
How does your body react when it is cold? How does it warm up?
Controlling the cold :
Shivering
Hairs erect (capture more air)
Vasodilation: When the blood vessels dilates (increase in size) causing more heat to be carried by the blood to the skin.
What is the definition of diabtetes?
A disorder in which the blood glucose levels remain too high.
What is diabetes type 1?
Caused by a person becoming resistant to insulin It can be controlled by:
Monitoring the diet
Injecting insulin
What is diabetes type 2?
Caused by a lack of insulin. It can be controlled by:
Monitoring diet and exercise
There is a link between rising levels of obesity and increase in diabetes type 2.
How does your body react when it is warm? How does it cool down?
Controlling heat :
Can be lost by sweating, which increases heat loss by evaporation
Vasoconstriction: When the circumference of blood vessels gets smaller
How are blood sugar levels controlled?
by releasing and storing glucose. This is controlled by insulin which is a hormone secreted by the pancreas.
What does evaporation mean?
From a liquid to a gas.
Where does aerobic respiration take place?
In animal and plant mitochondria.
Where does anaerobic respiration take place?
Cytoplasm of the cell.
Happens in muscle during hard exercise.
What are the 3 tests for gases?
HYDROGEN
A lit wooden splint makes a popping sound in a test tube of hydrogen.
OXYGEN
A glowing wooden splint relights in a test tube of oxygen.
CARBON DIOXIDE
Carbon dioxide turns limewater milky. A lighted wooden splint goes out in a test tube of carbon dioxide but this happens with other gases, too. So the limewater test is a better choice.
Where is the central nervous system (CNS)?
The central nervous system (CNS)- the brain and spinal cord.
Which nervous system carries information from one body part to another?
The peripheral nervous system - nerve cells which carry information to or from the CNS. Fast but short signals. Responds to the outside environment, bruises, getting hit.
What are neurons?
Also known as nerve cells. They carry electrical impulses from one place to another.
What relationship do receptors and effectors?
Receptor -> sensory neurons -> CNS -motors neurons -> Effector
What is a receptor?
Groups of cells which detect change in the environment (stimulus) and produce electrical impulses in response.
What is an effector?
Effectors are parts of the body which produce a response to a stimulus. For example: a muscle contracting to move an arm.
What is a synapse?
Gap between neurons.
Information crosses this gap using neurotransmitters (a type of chemical) produced by neurons.
Once the neurotransmitters crossed the gap they make the other neuron transmit an electrical impulse.
What does the endocrine system consist of?
Hormones which are chemical substances that help regulate processes in the body. They are secreted (produced) by glands. The bloodstream transports hormones from the glands to the target organs.
Slow to respond, goes through all the body no matter it's target. It is long lasting. Controls the internal environment, e.g. height, metabolism, reproductive system, appetite.
What is sexual reproduction?
2 people
Humans, plants, yeast
Done by meiosis
What is asexual reproduction?
1 person
Asexual reproduction does not involve sex cells. Only one parent is required. No fusion of gametes (sex cells sperm and eggs). The offspring is identical to the parent, meaning they are clones (genetically identical to another organism). For example, bacteria and plants.
Results in 4 sex cells.
What is an allele?
Different versions of the same gene. We have two alleles, 1 from mum and 1 from dad. Recessive: Alleles are represented in lower case letters. Aa Dominant: Alleles represented by capital letters. Aa or AA
What is a phenotype?
Physical characteristics (blue eyes, brown hair, etc).
Whta is a genotype?
The genes the person has (BB, Bb or bb)
Whta is a gamete?
A sex cells, sperm and eggs.
How do you determine sex?
Humans have 23 pairs of chromosomes. Twenty-two pairs control different characteristics, the last 1 pairs determine the sex.
Female: have two X chromosomes.
Male: have two different sex chromosomes, X (shown as larger chromosome) and Y (shown as smaller chromosome)
Mendel and the peas@
Mendel was a scientist whom cross fertilize pea plants.
He observed the different traits as well as the different phenotypes.
He made a discovery that green and yellow doesn't make "green-yellow" but rather it makes either green or yellow. The way to know which alleles recessive and which ones are dominant.
Whta does MRS. GREN stand for?
M ovement R espiration S ensitivity G rowth R eproduction E xcretion N utrition
The classificaton ladder:
Kingdom Phylum Class Order Family Genus Species
To remember the classificaton ladder:
King Philip Classified Over Fifty Green Spiders
Laboratory equipment
Hazards:
Something that can cause harm to someone, adverse health effects, either straightaway or later.
Dependant variable
The variable thing you measure.
Independant variable
The thing that will be changed in each experiment.
Controlled variable
A variable that is not changed.
Extremophile
Generally a single cell which lives in an extreme environment.
Electricity circuit elements
Fixed Resistor
Limits the flow of electrical current. Resistance that does not change.
Variable resistor
Moving, changes the resistance.
Charge vs current
Law of conservation of energy:
Energy cannot be created or destroyed.
Energy can only change from one type of energy to another type.
Noticed by Abraham Lincoln.
Efficiency
Efficiency is a measure of how much useful energy is converted efficiency = useful energy out ÷ total energy in (for a decimal efficiency)
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