Practice Questions Flashcards
Describe homeostasis
The regulation of internal conditions of a cell or organism to maintain optimum conditions for function, in response to internal and external changes
During exercise, what causes the skin to appear red?
Vasodilation of blood vessels
How does the thermoregulatory centre send information to sweat glands in the skin?
Via nerve impulses
Explain why the temperature near the brain decreased after drinking cold water
Blood is cooled at the stomach and then flows to the brain
Describe the advantages and disadvantages of having a kidney transplant instead of having dialysis
Advantages:
- no need for regular hospital visits
- flexible lifestyle, no need to control diet
- cheaper long term for the NHS
Disadvantages:
- risk of rejection
- need to take immunosuppressant drugs
- risk from surgery and long recovery time
Which organ produces urine?
Kidney
Name the process by which water is lost from the skin
Sweating
Why does the body need to lose water from the skin?
- For cooling
- To maintain body temperature
Describe how the body responds when a decrease in core body temperature is detected
- Vasoconstriction of blood vessels
- Less blood flow so less energy is lost to the surroundings
- Less sweating occurs
- Shivering by muscle contraction
- Respiring more
How does the lens refract light more?
By becoming thicker
Which two structures control the shape of the lens?
Ciliary muscles and suspensory ligaments
What is meant by the term ‘reflex action’?
An automatic response
Give three ways coordination by the endocrine system is different from coordination by the nervous system
Co-ordination by the endocrine system is:
- slower
- longer lasting
- via chemical hormones in the blood instead of neurones
Describe how hormones control the menstrual cycle
- FSH stimulates the maturation of an egg
- Oestrogen inhibits the release of FSH and stimulates the LH production
- LH stimulates ovulation
- Progesterone inhibits both LH and FSH production
- Oestrogen and progesterone maintain the uterus lining
Which part of the brain controls balance when riding a bicycle?
Cerebellum
What type of cell carries impulses from the ears to the brain?
Neurone
Describe how the brain receives information about light entering the eye
- Retina cells sensitive to light
- Impulse passes along sensory neurones
- Along optic nerve
What is a hormone? (3 marks)
- a chemical messenger, made by the endocrine system
- it is secreted by a gland and transmitted in the bloodstream
- where it travels to the target organ
Suggest why a blood test is more reliable than a urine test
There is not a lot of glucose in urine compared to the blood
Name the structures inside the cell nucleus that contain DNA
chromosomes
What type of substance does a gene code for?
Protein
What is the name of the type of cell division that produces sperm cells?
Meiosis
How could the student keep the milk at a constant temperature for 5 days?
Place the beaker in a water bath
What is meant by the term ‘reflex action’?
An automatic response
Describe how algae get energy
- From light
- Absorbed by chlorophyll
Name two types of microorganisms that cause decay
- Bacteria
- Fungi
Name the product that causes the pH to decrease
Fatty acids
Give one way the pH can be measured
- Using a pH probe
- Universal indicator
Describe how fishing quotas can help to return fish stocks to a sustainable level
- Fewer fish are caught
- So more remaining fish that can reproduce
Describe why more land is being used for farming and how increased farming has decreased biodiversity
- Increasing population requires more food, so more crops and livestock are grown for food
- Farming crops are also grown to be used as biofuels
- To create more land for farming, deforestation levels have increased which destroys habitats for animals, decreasing biodiversity
What are three uses of gibberellins?
- To start germination
- To increase fruit size
- To promote flower production
Why does storing bananas with other fruits cause the other fruits to ripen faster?
Ethene is released from the bananas
Why is DNA described as a polymer?
It is made up of many joined nucleotides
Describe the structure of a nucleotide
- Made up of a phosphate
- Which is attached to a sugar
- The sugar is attached to one of four bases
- The bases are A, C, T, G
Describe how non-coding parts of DNA can affect the expression of genes
The non-coding parts can switch genes on or off