Living Systems (Yr_8) Flashcards
What is the equation for photosynthesis?
6CO2 + 6H2O to C6H12O6 + 6O2
What is the equation for respiration?
C6H12O6 + 6O2 to 6CO2 + 6H2O
Describe how plants absorb water, nutrients and perform gas exchange:
- roots absorb water and nutrients and transports them
- the cell membrane acts as a selective banner for diffusion
- water easily diffuses through the membrane
- salt and sugars do not pass through as easily directly
- the cell membrane utilises osmosis to move water from an area of higher water concentration, through the cell membrane to an area of lower water concentration
- the cytoplasm in root hair cells contains lot of dissolved substances so the water I the soil moves into the plant through osmosis
- root hairs are elongated to speed up the process
- water and some dissolved minerals move through a part of the vascular bundle called xylem tissue
- the main force that moves water from the roots up to the leaves is the pressure from transpiration
Define diffusion:
a mixing process in which substances move from a place where ti is highly concentrated until it is evenly spread out
Define osmosis:
the movement of water through a semipermeable membrane, always from higher water concentration to lower water concentration
Define higher water concentration
less dissolved substances
Define lower water concentration
more dissolved substances
Define cytoplasm
the gelatinous liquid that fills the insides of a cell
Define root hair cells
Tiny extensions or projections from the outer surface of plant roots
Define xylem tissue
made of long tube-like cells that are not living
Define transpiration
the process in which plants release inside t\it in the form of moisture or vapour
Describe what happens in gas exchange
- it involves both carbon dioxide and oxygen
- carbon dioxide is absorbed for photosynthesis and oxygen is released
- during respiration, oxygen is absorbed and carbon dioxide is released through pores in leaves and stems
Describe the characteristics of asexual reproduction
- requires only one parent
- offspring has 100% same chromosomes as the parent
- offspring are clones
- vegetative reproduction
- no seed formation
List some examples of asexual reproduction
- binary fission in bacteria
- plant cuttings like grafting, cutting, layering
- fragmentation like flatworms
- budding like yeast
List the characteristics of sexual reproduction
- requires two parents to each give half of the genetic information
- offspring shares characteristics of each parent
Internal: - the egg is fertilised by sperm inside the female with animals like mammals, birds, reptiles, insects and spiders
External: - the egg is fertilised outside the female
the female lays eggs then the male fertilises with animals like fish, some amphibians, plants fungi
Define reproduction
a process where offsprings are created
Define asexual reproduction
no gametes
Define sexual reproduction
gametes
Define gametes
Gametes can be divided into male & female;
Male:
plants: pollen grains
animals: sperms
Female:
ovules, ova, ovum, egg, cell
ova/egg
Define fertilisation
the process of zygote formation
Label all the parts of a flower
stigma
anther
style
carpel
ovary
ovum
filament
sepals
stamen
petals
Define mitosis
A type of cell division where one parent cell divides to daughter cells with identical genetic instructions carried in their DNA
What is the role of mitosis in growth and repair?
As mitosis makes identical cell copies ii aids in repairing or replacing damaged cells
What is the role of mitosis in gamete production?
Mitosis occurs in somatic cells aka non-reproductive cells, whichever cells do not produce gametes. This occurs in the first stage after fertilisation. (Sperm and egg fuse, zygote is made, zygote goes through mitosis)
List all the major organs involved in digestion
Teeth & mouth
Oesophagus
Stomach
Liver & gallbladder
Pancreas
Small intestine
Large intestine
rectum & anus
State the role of the teeth and mouth in digestion
They do the physical breakdown of food and the tongue pushes food towards the teeth. (mechanical digestion) Saliva contains enzymes to start chemical digestion.
State the role of the oesophagus in digestion
A tubular muscle that forces food down to your stomach in a process called peristalsis.
State the role of the stomach in digestion
stores food for about 3 hours while it uses gastric juices to help digest the food. The food in your stomach is called chyme.
State the role of the liver & gallbladder in digestion
The liver makes a mixture of chemicals called bile used to digest fat and neutralise stomach acid. Bile is stored in the gallbladder until food reaches the small intestine. Bile is then released into the small intestine through a tube called the bile duct. Food does not travel through the liver.
State the role of the pancreas
They make pancreatic juice when contains a mixture of digestive enzymes and also neutralises stomach acid. Food does not travel through the pancreas.
State the role of the small intestine
The intestines are really important because they absorb the nutrients that all the cells of the body require
State the role of the large intestine
Some vitamins are absorbed into the bloodstream for the large intestine
State the role of the rectum & anus
The rectum stores faeces until it starts to become full. As it starts to stretch, messages are sent to the brain to make you realise you need to go to/ the toilet. Rectal muscles push the faeces out of the ring of muscles called the anus.
Label a diagram of the heart and trace out the route of blood around the heart
do it somewhere else
Explain the difference between breathing and respiration:
respiration is the actual process that happens in cells which is the same reaction as seen in plant cells. The energy produced is used for all the jobs the cell needs to perform. On the other hand, breathing is the inhalation of oxygen and exhalation of carbon dioxide by your lungs and other organs in the respiratory.
Identify the organs involved in excretion
kidney
ureters
bladder
urethra
State the role of the kidney
They are a pair of pyramid - shaped lobes. Blood carrying waste products enters your kidney to be filtered by tiny structures called nephrons. The kidneys are also for regulating levels of water and salts in the blood.
State the role of the ureters
urine formed in the kidney’s travels down two thin tubes called ureters to the bladder
State the role of the bladder
the bladder stores urine until it is ready to be expelled from the body
State the role of the urethra
When you urinate, urine is expelled from the bladder through the urethra and out the body. Other organs like the liver, skin and large intestine also plays roles in the excretion by processing toxins and expelling waste
What is the three types of muscles?
skeletal
smooth
cardiac
Describe the function of muscular/skeletal system
For skeletal muscles, muscle fibres are bundled together and the end of the muscle, the connective tissue combines to form tendons that attach to skeleton. They bring about voluntary movement
Smooth muscles that contract automatically in internal organs such as the digestive tract & uterus
Describe the role of the skeletal/muscular system
- enables movement such as walking and running
- provides a framework which supports the body;s shape and organs
- safeguards organs from external impacts
- bones act as levers, working with muscles to enable movement
- bones store essential minerals
Describe the role of the excretory system
- system in organisms that specialises in removing waste]
- needed to maintain chemical homeostasis to keep the body functioning
Describe the role of the circulatory & respiratory system
- responsible for transporting oxygen nutrients hormones and waste products
- main function is to breath in oxygen and breathe out carbon dioxide which allows oxygen to be diffused into blood for the circulatory system
Describe the role of the digestive system
- takes in food and liquid, breaking them down and absorbing the nutrients that the body needs to function
- also involved in waste management process
Label all the parts of the female reproductive system
