Question | Answer |
Why do multicellular organisms need to go through cell division? | for growth and repair |
Why is it important that the new daughter cells have the same number of chromosomes as the original parent cell? | so they maintain the diploid chromosome complement, |
What happens to the chromosomes during stage 2 of mitosis? | they condense and replicate |
What happens to the nuclear membrane during stage 2 of mitosis? | starts to break down |
Where do the chromosomes line up during stage 3 of mitosis? | equator (middle) of the cell |
What attaches to the chromosomes during stage 4 of mitosis? | spindle fibres |
What do the spindle fibres pull apart during stage 4 of mitosis? | chromatids |
What reforms around the groups of chromosomes during stage 5 of mitosis? | new nuclear membrane |
What starts to happen to the cytoplasm during stage 5 of mitosis? | It divides |
What is produced during stage 6 of mitosis? | 2 new identical daughter cells |
If a parent cell has 16 chromosomes, how many will each of the daughter cells have that are made during mitosis? | 16 |
Why do unicellular organisms need to do cell division? | for reproduction |
If one cell divides every 10 minutes how many cells will be present after 50 minutes? | 32 |
What is the name for an unspecialised cell? | stem cell |
What are the two functions of stem cells? | Growth and repair |
What are stem cells required for? | self-renewal and producing specialised cells |
Where are stem cells located in the human body? | Bone marrow, skin, muscle |
Give a medical use of stem cells | Treat cancer, diabetes, make skin grafts, organ transplants |
What is the ethical issue with embryonic stem cells | kills the embryo |
State the order of life. | cell -> tissue -> organ -> organ system |
What is a tissue? | Groups of similar cells working together to perform the same function |
What is an organ? | Groups of similar tissues working together to perform the same function |
What is an organ system? | Groups of organs working together |
An organism made up of more than one cell is called? | Multicelllular |
An organism made up of one cell is called? | Unicellular |
What is the specialisation of a red blood cell? | No nucleus, Biconcave shape, contains haemoglobin |
What is the function of a sperm cell? | fertilise the egg |
What is the specialisation of a sperm cell? | tail to swim |
What is the function of a red blood cell? | Carries oxygen around the body |
What is the nervous system composed of? | Brain, Spinal Cord and Nerves |
What is the central nervous system composed of? | Brain and Spinal cord |
Which part of the brain controls thought and personality? | Cerebrum |
Which part of the brain controls balance and coordination? | Cerebellum |
Which part of the brain controls heart rate? | Medulla |
What is the function of the Medulla? | controls breathing and heart rate |
What is the function of the Cerebrum? | Controls thought and personality |
What is the function of the Cerebellum? | Controls balance and coordination |
What are the three neurons present in the reflex arc? | Sensory, inter and motor (SIM) |
What is the function of the receptors in the reflex arc? | detect stimulus (e.g sharp object) |
Which neuron passes information from the inter nerve to the effector? | Motor nerve |
What is the function of the sensory neuron? | Passes information from the receptors to the inter neuron |
Which neuron is found in the CNS? | Inter |
Give two examples of an effector. | Muscles and Glands |
What is the function of an effector? | To produce a response |
What is the function of the inter neuron? | To pass information from the sensory to the motor neuron |
What is the gap between neurons called? | Synapse |
What is the function of the reflex arc? | to protect the body |
What diffuses between the neurons? | chemical messages |
What passes along a neuron? | electrical impulses |
Which gland releases hormones? | Endocrine |
Hormones are chemical messengers that travel in the? | bloodstream |
What are hormones made of? | protein |
What are the specific proteins that hormones bind to on target tissues called? | receptors |
Do hormones have a faster or slower response than nerves? | slower |
Which has a longer lasting effect, nerves or hormones? | hormones |
Which endocrine organ releases insulin and glucagon? | Pancreas |
When is insulin released? | blood sugar too high |
What is insulin's target tissue? | Liver |
What is insulin's function? | To convert glucose into glycogen |
Which gland releases hormones? | Endocrine |
Hormones are chemical messengers that travel in the? | bloodstream |
What are hormones made of? | protein |
What are the specific proteins that hormones bind to on target tissues called? | receptors |
Do hormones have a faster or slower response than nerves? | slower |
Which has a longer lasting effect, nerves or hormones? | hormones |
Which endocrine organ releases insulin and glucagon? | Pancreas |
When is insulin released? | blood sugar too high (hIIIIIIgh) |
What is insulin's target tissue? | Liver |
What is insulin's function? | To convert glucose into glycogen |
What is the function of the pancreas? | detects changes in blood sugar and releases hormones |
Where is glycogen stored? | Liver |
When is glucagon released? | blood sugar too low (glucose is gone) |
What is glucagon's function? | To convert glycogen into glucose |
Why is insulin released? | To lower blood glucose levels |
Why is glucagon released? | To increase blood glucose levels |
What is Diabetes? | failure to produce insulin from the pancreas. |
What is digestion? | breakdown of large insoluble molecules into small soluble molecules (BLISS) |
What is protein broken down into? | amino acids |
What is fat broken down into? | fatty acids and glycerol |
What is starch broken down into? | maltose |
What is the name for the finger-like projections in the small intestine? | Villi |
What is the function of the villi? | Absorb nutrients from food |
Why is the small intestine good at absorbing food? | large number of villi providing a large surface area. |
Give four features of the villi that allow them to easily absorb nutrients | Large surface area, thin lining, good blood supply, high number of villi |
Which part of the villi absorbs fatty acids and glycerol? | Lacteal |
Which component of the villi absorbs glucose and amino acids? | Blood capillary |
What does the blood capillary absorb? | glucose and amino acids |
What does the lacteal absorb? | fatty acids and glycerol |
What needs to be absorbed from the bloodstream? | oxygen and nutrients |
What is the waste material removed from cells into the bloodstream? | carbon dioxide |
What are the main gas exchange organs? | the Lungs |
What do the lungs contain that provide them with a large surface area? | a large number of alveoli |
What are the 3 features of alveoli that allow gas exchange? | Large surface area, good blood supply, thin walls |
Give one feature of tissues which allows them to exchange materials with cells? | They have capillary networks. |
What does the blood contain? | plasma, red blood cells and white blood cells. |
What are the main substances that the blood transports? | oxygen, carbon dioxide & nutrients |
What is the function of white blood cells? | To destroy pathogens |
Which white blood cell engulfs pathogens through phagocytosis? | Phagocytes |
What is the function of lymphocytes? | produce specific antibodies which destroy pathogens |
Why are antibodies specific? | They only bind to a particular pathogen |
Which blood vessels carries blood into the heart? | Vein |
Which blood vessels carries blood into the heart? | Artery |
Which blood vessel is the site of gas exchange? | Capillaries |
Describe the structure of arteries | Thick wall, thick muscular layer, narrow channel |
Describe the structure of veins | thin wall, thin muscular layer, wide channel, valves |
Describe the structure of capillaries? | Thin wall (1 cell), highly branched forming networks, large surface area |
Which side of the heart contains oxygenated blood? | Left |
Which side of the heart contains deoxygenated blood? | Right |
What are the two receiving chambers called? | Atria (atrium) |
What are the two pumping chambers called? | Ventricles |
What is the function of the left side of the heart? | Pumps blood to the body |
What is the function of the right side of the heart? | Pumps blood to the lungs to be oxygenated |
Which blood vessel takes blood into the heart from the body? | Vena Cava |
Which blood vessel takes blood into the heart from the lungs? | Pulmonary vein |
Which blood vessel takes blood away from the heart to the body? | Aorta |
Which blood vessel takes blood away from the heart to the lungs? | Pulmonary artery |
What is the function of the coronary artery? | Provides heart with nutrients and oxygen |
What happens when the coronary artery becomes blocked? | Oxygen cannot get to the heart causing a heart attack |
Which blood vessel carries blood under high pressure? | Arteries |
What is the function of valves? | prevent the backflow of blood |
Which blood vessel carries blood under low pressure? | Veins |
How many valves are within the heart? | Four |
What is the function of the xylem? | Transports water up the plant |
What is the function of the phloem? | Transports sugar up and down the plant. |
What provides the xylem with support? | Rings of lignin |
Is the xylem or phloem dead? | Xylem |
What is the function of the upper and lower epidermis in a plant leaf? | Protection |
What is the function of the palisade mesophyll cells? | Photosynthesis |
Which cells allow the opening and closing of the stomata | Guard cells. |
What structures are present in the phloem? | Sieve tubes, sieve plates, companion cells. |
State two functions of the stomata. | Gas exchange and evapouration of water |
What is transpiration? | The evapouration of water from the stomata |
What is the transpiration stream? | Movement of water from root to leaves |
What process allows water to move into the root hair cells | Osmosis |
What process allows water to move up the xylem | Osmosis |
Which structures are found in the transpiration stream? | Root hair cells, xylem, stomata |
What effect does increasing temperature have on transpiration? | Increases transpiration |
What effect does increasing humidity have on transpiration? | decreases transpiration |
What effect does increasing surface area have on transpiration? | Increases transpiration |
What effect does decreasing wind speed have on transpiration? | decreases transpiration |
Cells which contain two sets of chromosomes are called? | Diploid |
Cells which contain one set of chromosomes are called? | Haploid |
Which cells in the human body are haploid? | Gametes (sex cells) |
What is the male gamete in animals called and where is it produced? | Sperm - Testes |
What is the female gamete in animals called and where is it produced? | Egg - Ovary |
What is the male gamete in plants called and where is it produced? | Pollen - Anther |
What is the female gamete in plants called and where is it produced? | Ovule - Ovary |
What is fertilisation? | The fusion of the nuclei of two haploid gametes to produce a diploid zygote |
What does a zygote divide to form? | An embryo |
What is discrete variation? | Can be split up into 2 or more groups |
What is continuous variation? | Shows a range of values |
Tongue rolling is an example of? | Discrete variation |
Height is an example of? | Continuous variation |
What is an allele? | Different forms of the same gene |
What is a phenotype? | The physical appearance due to genetic trait |
Give an example of a phenotype | Blue eyes |
What is a genotype? | the 2 alleles present e.g. BB or bb or Bb |
How many dominant alleles do you need to allow the dominant phenotype to show | One |
How many recessive alleles do you need to allow the recessive phenotype to show | Two |
What is homozygous? | Two of the same alleles (e.g. BB or bb) |
What is heterozygous? | Two different alleles (e.g. Bb) |
What is polygenic inheritance? | Characteristic controlled by more than one gene |
Most traits are usually? | polygenic and continuous |
What are the names for the generations in a family tree? | P, F1 and F2 |
Why are predicted ratios of offspring not always the observed ratio? | Fertilisation is a random process. |