Biology Flashcards
Structure of the eye and functions
the eye is a sense organ
It contains receptor cells that are sensitive to
light: rod cells
Colour: cone cells
Cornea
Transparent lens that refracted light as it enters the eye
iris
Controls how much light enters the pupil
lens
Transparent disc that can change shape to focus light onto the retina
Retina
Contains light receptor cells - rods detect light intensity and cones detect colour
Optic nerve
sensory neurone that carries impulses between the eye and the brain
pupil
Hole that allows light to enter the eye
the pupil reflex
The muscles of the iris control how much light enters the eye, depending on whether we are in a bright or dim environment.
What are the two types of receptor cells in the retina
rods which are sensitive to dim light
Cones which distinguish between different colours in bright light
Hormone
a chemical substance produced by a gland and carried by the blood, which alters the activity of one or more specific target organs
what are the glands that produce hormones in animals called
endocrine system
Growth hormone
regulates growth and physical development. It can stimulate growth in almost all of your tissues. Its primary targets are bones and muscles
Thyroid-stimulating hormone
This hormoneactivates your thyroid to release thyroid hormones. Your thyroid gland and the hormones it produces are crucial for metabolism.
Adrenocorticotropic hormone.
This hormonestimulates your adrenal glands to produce cortisol and other hormones.
Follicle-stimulating hormone.
is involved with oestrogen secretion and the growth of egg cells in women. It’s also important for sperm cell production in men
Luteinising hormone
is involved in the production of estrogen in women and testosterone in men.
Adrenaline is known as
the fight or flight hormone as it isproduced in situations where the body may be in danger
What does adrenaline do to the body
Increasing blood glucose concentrationforincreased respiration in muscle cells
Increasing pulse rateandbreathing rateso glucose and oxygen can bedelivered to muscle cells, and carbon dioxide taken away, from muscles cellsmore quickly
Diverting blood flow towards musclesand away from non-essential parts of the body such as the alimentary canal; again to ensure the reactants of respiration are as available as possible
Dilating pupilsto allow as much light as possible to reach the retina somore information can be sent to the brain
Problems that can be caused by malnutrition
constipiation
Coronary heart disease
obesity
Which tissue in the stem does liquid travel through to reach the petals?
xylem
Describe the correct sequence for the movement of blood in a mammal
body -> heart -> lungs -> heart
Describe species
a group of organisms that reproduce to produce fertile offspring
Two features of most reptiles
Fertilisation is internal
Lay eggs
Transpiration is the loss of water vapour from plant leaves by _______
Evaporation
the effect of humidity on the rate of transpiration
As humidity increases the rate of transpiration decreases
State the name of vessels that transport water in plants
xylem
State the name of the cells where water enter a plant
root hair cell
Two other parts of the large intestine
Colon, Rectum
Which structure carries nerve impulses away from the central nervous system
motor nerve
Describe a simple reflex arc
For example, a simple reflex arc happens if we accidentally touch something hot. Receptor in the skin detects a stimulus (the change in temperature). Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS
State the name of the junction between two neurones
synapse
Diabetes type 1
a condition where the blood glucose levels are not able to be regulated as the insulin secreting cells in the pancreas are not able to produce insulin
State the storage carbohydrate made from glucose in liver cells
Glycogen
two ways the body releases water
Sweating
Excreting
Name the part of the body which coordinates the changes in the skin to keep the body temperature
at 37 °C
Brain
List three stimuli that are detected by sense organs.
light
sound
temperature
the process that allows the eye to view objects at different distances.
accommodation
the part of the eye that has the highest concentration of light-sensitive cells and gives the
most detailed image.
fovea
State the name of the organ that produces adrenaline
adrenal (gland)
Define drugs
A substance taken into the body that modifies or affects chemical reactions
define the use of antibiotics
The treatment of bacterial infection
Are all bacteria resistant to antibiotics
Some bacteria are resistant but others are not
The effects of excessive alcohol consumption and abuse of heroin
you have less self control
You are worse at driving
You feel numb
more likely to commit crime
What infection can you get from heroin
HIV
What can excessive alcohol consumption cause
liver damage
What can tobacco smoking cause
chronic obstructive pulmonary disease, lung cancer, coronary heart disease.
What is the site of break down of alcohol and other toxins
the liver
What does heroin do to the nervous system
It slows down the nervous system
what do medical drugs do
They relive pain
How do antibiotics work
Antibiotics work by blocking vital processes in bacteria, killing the bacteria or stopping them from multiplying. This helps the body’s natural immune system to fight the bacterial infection. Different antibiotics work against different types of bacteria.
why do antibiotics not kill viruses
Antibiotics cannot kill viruses because viruses have different structures and replicate in a different way than bacteria
how do bacteria become resistant to antibiotics
Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other germs become resistant
how can we minimise the number of bacteria that become resistant to antibiotics
Minimise unnecessary prescribing and overprescribing of antibiotics. …
Complete the entire course of any prescribed antibiotic so that it can be fully effective and not breed resistance.
Practise good hygiene such as hand-washing and use appropriate infection control procedures.
The effects of the abuse of heroin
heroin is a powerful depressant
It is a narcotic, producing a dream like feeling of relaxation and reducing severe pain
it is very addictive
The body develops a tolerance for the drug, so people increase the amount they take. Thus leading to death by overdose
withdrawal symptoms of heroin
Cramp, insomnia, vomiting, sweating, hallucinations
Describe two effects of adrenaline on the body
increased rate of breathing
increased pulse and heart rate
hormone released from the b a l l z
Testosterone
Effects of small amounts of alcohol on body
• Small amounts – alcohol can relax the body and create a sense of wellbeing
negative effects of alcohol
- Poor judgments may leads to criminal activity and sexual promiscuity.
- Long-term excessive drinking can lead to addiction (alcoholism).
- This can lead to financial difficulties and family problems.
- As the liver removes alcohol from the blood, heavy drinking can leas to liver damage such as cirrhosis
• Drinking can cause brain damage, peptic ulcers in the stomach and obesity.
What is phototropism
Plant’s response to light
What does the colours in urine mean
Dark yellow: Drink more water
Light yellow or clear: You are hydrated enough
Pee can be dark if you exercise, or if it is too hot.
the role of the liver
The assimilation of amino acids by converting them to proteins
deamination
The removal of nitrogen containing part of amino acids to form urea
why do we need excretion
helps make the urea less toxic
The structure of the kidney
the cortex, medulla, ureter.
Why is kidney transplant better than dialysis
it is more convenient
One substance that is excreted from the lungs and where it is produced
CO2, produced in cells
One excretory substance that is removed by the kidneys, that contains nitrogen
urea
Name the structure within a kidney that filters the blood
glomerulus
The name of the mechanism that controls homeostasis
Negative feedback
Two features of prokaryotes
no nucleus
Cell wall
