Biology Flashcards
State the 7 characteristics of living organisms.
- Growth
- Reproduction
- Respiration
- Reproduction
- Growth
- Sensitivity
- Nutrition
State the formula for magnification.
Image size/Actual size
What is cell wall made of?
Cellulose (cellulose is made of polysaccharide)
What sort of reactions take place in cytoplasm?
Metabolic reactions
What does vacuole contain?
Cell sap
What do chloroplasts contain?
Chlorophyll
What does nucleus contain?
Chromosomes (chromosomes are made of DNA)
State what is meant by diffusion.
The net movement of molecules from an area of high concentration to low concentration, down a concentration gradient
What is osmosis?
The net movement of water molecules form an area of high potential to low potential
What happens to animal cells in the following:
a) pure water
b) concentrated solution
a) It bursts; water osmoses inside
b) it shrinks; water osmoses out
What is turgor pressure?
The outward pressure of cell membrane on cell wall
When does a cell become flaccid?
When the cell becomes floppy
What are single-molecule sugars called?
Monosaccharides
What are double-molecule sugars called?
Disaccharides
What are sugars with multiple molecules called?
Polysaccharides
What is the test for reducing sugar called? [State the observation too]
Benedict’s test
Blue–>Green–>Yellow–>Orange–>Brick-red
What is the test for starch? [State the observation too]
Iodine test
Orange-brown–>Blue-Black
What is the test for fat? [State the observation too]
Emulsion test
White precipitate
What is the test for protein? [State the observation too]
Biuret test
Blue–>Purple
What small molecules, are proteins made of?
Amino acids
What is a catalyst?
A substance that increases the rate of reaction and is not changed by the reaction
What are enzymes?
Proteins which act as biological catalysts
What enzymes are used to digest the following:
a) Starch
b) Protein
c) Carbohydrates
d) Fats
a) Amylase
b) Protease
c) Carbohydrase
d) Lipase
What are substances at the beginning and end of a reaction called (in context of enzymes)?
Substrate and products, respectively
How does an enzyme work?
- Enzyme molecule is like a lock
- The substrate must be a perfect fit
- It fits into the enzyme
- The enzyme changes the substrate into new molecules called products
When does an enzyme become denatured?
When it can no longer catalyze a reaction
What is photosynthesis?
The process by which plants manufacture carbohydrates from raw materials using energy from light
State the equation of photosynthesis (both word and symbolic)
Carbon dioxide + water —> glucose + oxygen
CO2 + H20 —> C6H12O6 + O2
Why is glucose changed to sucrose for transport?
Glucose is quite reactive
State the procedure to test leaves for starch.
- Boil the leaf in water
- Dip it in a testube of ethanol/alcohol
- Place that testube in warm water to remove chlorophyll
- Gently remove the leaf from the testube and place it on a white tile
- Drop iodine on the leaf
Define balanced diet.
A diet which contains all 7 types of nutrients in the correct amount.
Describe the 2 types of digestion methods?
Mechanical digestion is when the food particles are broken down into smaller pieces without chemical change
Chemical digestion is when the food particles are broken down into smaller pieces using chemical processes
State the parts of a teeth.
Enamel; dentine; pulp cavity; gum; cement; fibres attaching teeth to jawbone
State the different types
of teeth and describe their use.
Incisors- bite off pieces of food
Canines- bite off pieces of food
Premolars- grinding food
Molars- grinding food
What absorbs digested fats in a villus?
Lacteal
What is absorption?
The movement of digested food molecules from the digestive system into the blood
What are the substances that comprise saliva?
Water
Mucus
Amylase (enzyme)
What is the mixture of food in the stomach called?
Chyme
Which protease breaks down proteins to polypeptides?
Trypsin
State the properties of bile.
- Contains sodium hydrogen carbonate to neutralize the acidic mixture form stomach
- Performs emulsification; breaking larger drops of fats into small ones for their quicker reaction with lipases.
Name the two vessels used for transportation in plants.
Xylem and phloem vessels
A group of xylem and phloem vessels is called __________.
Vascular bundle
Plants have __________ cells to absorb water.
Root hair
What is transpiration?
Loss of water vapor from plant’s leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapor through stomata.
What is cohesion?
The strong tendency of water molecules to stick together.
State two conditions that affect the rate of transpiration.
Temperature
Humidity
What is translocation?
The movement of sucrose and amino acids in phloem, from regions of production (source) to regions of storage (sink)
Which side of the heart pumps/receives:
a) Oxygenated blood
b) Deoxygenated blood
a) Left-side
b) Right-side
Blood vessels that:
a) Take the blood to the lungs and back are the
__________ system.
b) Take the blood to the rest of the body and back are
the _________ system.
a) Pulmonary
b) Systematic
How many chambers is the heart divided into? State the names.
Four chambers- Atria (upper two) & Ventricles (lower two)
The right atrium receives blood from the rest of the body, arriving through the __________
Venae cavae
What is the function of atria?
To receive blood from lungs/rest of the body
What is the function of ventricles?
To pump blood out of the heart to the rest of the body
What are some factors that lead to coronary heart diseases?
Smoking cigarettes
Diet (involving high levels of salts)
Obesity
Stress
Genes
What are one-way valves called? State their function.
Atrioventricular valves
Function- to stop the blood flow from ventricles back to the atria
Explain in brief:
a) Atrial contraction
b) Ventricular contraction
a) Muscles of atria contract; forces blood to flow into
the ventricles
b) Muscles of ventricles contract; forces blood to flow
out into the arteries
State the three main kinds of blood vessels and provide a brief explanation too.
Arteries
- blood flowing out of the heart enters the arteries.
- the blood flow is quite vigorous as it has been
pumped by the heart
- they have ‘elastic-tissues’ which can recoil and stretch
Capillaries
- arteries divide to form small capillaries
- they can penetrate in each and every part of the body
- they take nutrients to each cell and the waste
products away from cells
Veins
- capillaries gradually join together to form veins
- there is no need for veins to have thick walls as the
blood pressure by then, has significantly decreased
- the space inside veins, called lumen, is much wider
than the lumen of arteries
State the four parts of blood.
Plasma
Platelets
Red-blood cells
White-blood cells
__________ cells do not have a nucleus.
Red-blood cells
What are the function of white blood cells?
To fight pathogens and clear up dead body cells
The process of __________ involves taking in and digesting bacteria.
Phagocytosis
What is the function of platelets, and why are they necessary?
Function- blood clotting
To prevent pathogens from entering the body, and also to prevent blood-loss.
Define the following:
a) Aerobic respiration
b) Anaerobic respiration
a) Chemical reaction in cells which use oxygen to break down nutrient
molecules to release energy
b) The chemical reaction in cells which break down nutrient molecules to
release energy without using oxygen
State the equation for anaerobic respiration in:
a) Animals
b) Yeasts
a) Glucose –> lactic acid (+ energy)
b) Yeast –> alcohol + carbon dioxide
State 4 adaptations of the gas exchange surfaces.
- Thin to allow quick diffusion
- Close to the transport system to take gases to/from the surfaces
- Large surface area so a lot of gas can diffuse
- Good supply of oxygen
Give the parts (in order) from which oxygen passes to reach the lungs.
Trachea –> bronchi –> bronchioles –> alveoli –> lungs.
Why do goblet cells contain cilia and mucus?
The mucus stops pathogens from entering the body.
The cilia sweep the mucus to the back of the throat.
Define:
a) Inspired air
b) Expired air
a) Contains majority of oxygen than carbon dioxide.
b) Contains majority of carbon dioxide than oxygen.
