Structure and Functions of Living Organisms Flashcards
What gas do plants need to take in for aerobic respiration?
Oxygen (O2)
What gas to plants need to remove from respiration?
Carbon dioxide (CO2)
What gas do plants need to take in for photosynthesis?
Carbon dioxide (CO2)
What gas do plants need to remove from photosynthesis?
Oxygen (O2)
What gas do plants need to remove from photosynthesis?
Oxygen (O2)
Give 3 adaptations of leaf tissue for gas exchange
- Stomata (pores) allow diffusion of gases in and out of the plant
- Thin to shorten the diffusion distance
- Air spaces in the spongy mesophyll layer allow gases to diffuse
Why don’t plants keep the stomata open permanently?
Plants need to close the stomata to reduce water loss
Draw a graph to show how photosynthesis and respiration are affected by light intensity
Why do plants release more CO2 compared to O2 at night?
- Respiration continues during the night whereas photosynthesis does not
- Respiration releases CO2 and photosynthesis releases O2
Describe the general structure of the lungs
- Trachea branches into two bronchi
- Bronchi branch into bronchioles
- Bronchioles carry air to the alveoli
Describe the structure of an alveolus
- Small sacs with capillaries around them
- Contain a surfactant so walls don’t stick together and so gases can dissolve to help diffusion
What is the purpose of the pleural membrane?
The pleural membrane covers the lungs, reduces friction and keeps the lungs moist
What are the intercostal muscles?
They are a group of muscles found between the ribs that are involved in breathing by changing the size of the thorax
How do the diaphragm and intercostal muscles work together during expiration (breathing out)?
Expiration:
- Diaphragm relaxes and moves up
- External intercostal muscles relax
- Volume in the thorax decreases and air moves out
How do the diaphragm and intercostal muscles work together during inspiration (breathing in)?
Inspiration:
- Diaphragm contracts and moves down
- External intercostal muscles contract
- Volume in the thorax increases and air moves in
Give 3 health issues caused by smoking
- Cancer
- Bronchitis
- Coronary heart disease
How does smoker’s cough arise?
- Cilia on cells lining the trachea waft mucus containing dirt out of the lungs
- Smoking can kill cells lining the trachea
- A build-up of mucus in the lungs can cause people to develop smoker’s cough
What is the definition of
Diffusion?
The spreading out of particles from an area of higher concentration to an area of lower concentration.
What is the definition of Osmosis?
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
The larger the surface area of the membrane, does the diffusion rate get faster or slower?
Faster
What is the definition of Active Transport?
The movement of substances from more dilute solution to a more concentrated soltion (against the concentration gradient) using energy from respiration.
What is the definition of Cellular Respiration?
The process by which cells break down nutrients like Glucose etc into useable energy
What is the photosynthesis equation?
Carbon dioxide + water → Glucose + oxygen
6CO2 + 6H2O →
C6H12O6 + 6O2.
What is definition of phtosynthesis?
the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
What is the definition of Gaseous Exchange in humans?
At each cell, oxygen is exchanged for carbon dioxide - a waste gas.
Your bloodstream then carries this carbon dioxide back to the lungs where it is removed and then released
What is the definition of plant gaseous exchange?
The process by which plants take in carbon dioxide and release oxygen through tiny pores called stomata
What is the definition of transpiration?
the evaporation and movement of water away from the plant’s leaves from the inside of the plant.
What is the use of the waxy cuticle?
It is waterproof to prevent water loss
What is the purpose of the Upper Epidermis?
It is made up of tightly packed plant cells and it’s purpose is to maximise absorption of light due to it’s surface area.
When the concentration gradient increases, how does it affect the rate of diffusion?
The rate increases
Why does the diffusion rate increase when the temperature gets higher?
Because the particles have more energy.
What is the name of the process when dissolved substances move in and out of cells?
Diffusion
Why do molecules actually pass both ways through the membrane during Osmosis and Diffusion?
Because the molecules are moving about at random. But if there are a lot more particles on one side of the membrane then there is a net movement away from that side.
What is transpiration caused by?
The evaporation and diffusion of water from a plant’s surface
What does Photosynthesis use to change the carbon dioxide and water into glucose and oxygen?
Energy transferred to the chloroplasts from the environment by light.
In what ways do plants use Glucose?
- For respiration
- Converted into cellulose
- Making amino acids which are then made into proteins.
- Stored as lipids
- Stored as starch.
What are the limiting factors that can affect the rate of photosynthesis?
- Lack of light can be a limiting factor
- Low temperature
- Amount of CO2
What is the transpiration stream?
the current of water usually containing many substances in solution that rises through the xylem of plants.
What is Ingestion
Eating/ consuming food
What is digestion
Breakdown of large insoluble molecules into small molecules
What is absorption
The small soluble molecules absorb into the bloodstream
What is assimilation
The movement of digested food molecules into the cells of the body
What is egestion
The act of excreting unusable material from a cell
What is a limiting factor
A limiting factor is something that stops photosynthesis from happening any faster. The limiting factor usually depends on the environmental conditions. Eg. in winter the limiting factor is likely to be temperature or at night it is likely to be light.
What are Enzymes
Biological catalysts that increase the rate of reactions in living organisms.
What is the name of the artery and vein leading to the lungs?
pulmonary artery + pulmonary vein
What is the name of the artery and the vein leading to the legs?
Femoral artery + femoral vein
What is the name of the artery and the vein leading to the brain?
Carotid artery + jugular vein
What is the name of the artery and the vein leading to the stomach and the intestines?
Mesenteric artery + mesenteric vein
What is the name of the artery and the vein leading to the arm?
Subclavian artery + subclavian vein
does active transport require energy
yes
does diffusion require energy
no
does osmosis require energy
no
Give three adaptations of the lungs for gas exchange
- has many alveoli
- has a large surface area
- the walls of the alveoli are thin (one cell thick)
Define diffusion
The spreading out of particles resulting in a net movement from an area of higher concentration to an area of low concentration.
How does smoker’s cough arise?
- Cilia on cells lining the trachea waft mucus containing dirt out of the lungs
- Smoking can kill cells lining the trachea
- A build-up of mucus in the lungs can cause people to develop smoker’s cough
Give three adaptations of the lungs for gas exchange
- has many alveoli
- has a large surface area
- the walls of the alveoli are thin (one cell thick)
Homeostasis
The maintenance of a constant internal environment in the body
Nucleus
contains the genetic material that controls the activities of the cell
Mitochondria
Where most of the aerobic respiration takes place
Cytoplasm
Gel-like substance where most chemical reactions happen
Cell membrane
A partially permeable barrier that surround the cell.
Ribosomes
Where proteins are made in the cell
Difference between plant cells and animal cells
Plant cells have a cell wall and contain chloroplasts and organelles whereas animal cells have none
What is the definition of chloroplast
An organelle which is the site of photosynthesis
What is the function of a ribosome
Where proteins made in the cell
Why do muscle cells contain lots of mitochondria?
to generate the energy needed for contraction
Where can stem cells be found?
Early Human Embryos or Meristems
Why are some people against stem cell research?
Because they feel that it is wrong to experiment on human embryos as they are all potential human life.
What does cell differentiation mean?
the process by which a cell changes to suit its required function.
Describe how a root hair cell is specialised for its function.
It has long hairs to increase the surface area
Give an example of active transport in humans.
Taking glucose from the gut and from the kidney tubules.
How have sperm cells adapted to fit their purpose?
- Long tail and streamlined head to swim to the egg
- Lots of mitochondria in the cell to provide the energy needed
- Enzymes in its head to digest through the egg cell membrane
What do Phloem and Xylem tubes do?
they transport substances such as food and water around plants
What is the definition of a cell wall?
An outer layer made of cellulose that strengthens plant cells
Define mitosis
A type of cell diffusion which produces two genetically identical daughter cells from one parent cell.
Define Lipase
An enzyme that is produced in the pancreas that breaks lipids down into fatty acids and glycerol
Define protease
an enzyme produced in the stomach and pancreas that breaks proteins down into amino acids
Define pathogens
microorganisms that cause infectious disease
Define amylase
an enzyme produced in the salivary glands and pancreas. It breaks down carbs in to sugars.
Define bile
A substance made in the liver and stored in the gall bladder which is used to neutralise stomach acid and emulsify fat
Define blood
A tissue containing red blood cells, white blood cells, platelets and plasma.
