Revision Flashcards
Where in the heart is the pacemaker located?
In the Wall of right atrium
State one location of a semi-lunar valve.
Between the right ventricle and base of pulmonary artery
Name two substances other than food molecules and water found in the blood.
State where in the body they enter the the blood at.
Urea- Liver
Hormones- endocrine gland
What is the role of the sinotrial (SA) node?
Generates electrical impulses and causes contractions in the atria. (Atrial systole)
Where is the atrioventricular (AV) node located?
In the septum near the tricuspid valve
What is the function of the AV node?
Generates electrical impulses and causes contractions in the ventricles (Ventricular systole)
What exactly is being measured when a person’s blood pressure is taken?
The force of the blood against the wall of the artery
What is homeostasis?
The maintenance of a constant internal environment
Why is homeostasis important?
- Allows for efficient metabolic activity
- Keeps temperature suitable for enzyme reactions
What causes the brain to start inhalation?
Increased CO2 in the blood
Define mitosis.
Nuclear division forming two identical daughter cells
State two differences between mitosis and meiosis.
Meiosis-
- Has variation, does not produce identical cells
- Chromosome number is halved
What does diploid mean?
Means that there are two of each chromosome/ the chromosomes are in pairs
After the telophase of mitosis, how do animal cells split in two?
Cleavage furrow formation
After the telophase of mitosis, how do plant cells split in two?
Cell plate formation
What is the function of mitosis in single celled organisms?
Asexual reproduction
What it the purpose of mitosis in multi-celled organisms?
Tissue growth and repair
What does activation energy mean?
Energy needed to start a reaction.
What human enzyme has an optimum pH that is not 7?
Pepsin
Name the enzyme used in the experiment
Catalase
What reaction takes place when using the enzyme catalase?
Converts hydrogen peroxide to water and oxygen.
Name two substances used to immboilise enzymes or yeast.
- Sodium alginate
- Calcium chloride
Explain the term ‘cell’
Smallest unit that exhibits the characteristics of life.
Explain the term ‘organelle’
Performs specific functions in the cell
What is the function of ground tissue and where is it found in a plant?
Function- structural
Location- Between dermal and vascular tissue
Name an animal and plant cell organelle other than the nucleus that contains genetic material.
- Mitochondrion
- Chloroplast
Name the organ in the body in which deamination occurs.
Liver
Where is the site of production of sodium bicarbonate in relation to the digestive system?
Pancreas
What is nutrient recycling?
Is the way in which elements such as carbon and nitrogen are exchanged between living and non-living components of an ecosystem.
What is a food web?
A series of interconnected food chains
What are primary consumers?
They feed on producers (plants)
Name one abiotic factor.
Light intensity
State two ways in which carbon dioxide is returned to the atmosphere.
- Respiration
- Decomposition
What role does nitrogen-fixing bacteria play?
They convert nitrogen gas (N2) into ammonia (NH3)
What role does nitrifying bacteria play?
Converts ammonia (NH3) to nitrite and then into nitrate
Name a group of organism that return nitrogen to the air.
Denitrifying bacteria
Name a compound excreted by animals that returns nitrogen to the environment
Urea/urine
Name two ways that nitrogen can be artificially added to the soil.
- Slurry
- Artificial fertiliser
What does habitat mean?
The area in which an organism lives
What does community mean?
All of the organisms in an area
What does population mean?
All of the organisms of a particular species living in an area
Apart from nutrition, name another function of agar.
Provides a medium for growth
How are agar plates full of yeast safely disposed of after the experiment?
Autoclave
What sign is there that fermentation is taking place?
Bubbles of CO2 gas being released
Where in the cell does the dark stage take place?
Chloroplast
What type of agar is best suited for optimal growth of yeast and other fungi?
Malt agar
How do you identify the leaf yeast on the agar?
Presence of pink colonies
Whats the relationship between schwann cells and the myelin sheath?
Schwann cells make the myelin sheath
What is a synapse?
Region where two neurons come into close contact
Why are neurotransmitters required to carry the impulse across a synapse?
Electrical impulses cannot cross the synaptic cleft
What activates the neurotransmitters?
Ions
What is the fate of the neurotransmitters after an impulse has crossed the synapse?
They are inactivated by enzymes and reabsorbed
How many directions can impulses travel in?
Only one.
What is the cause of Parkinson’s disease?
A lack of dopamine
Treatments for Parkinson’s disease?
- Levadopa
- Dopamine agonists
- Physiotherapy
What light do rods detect?
Black and white, work in dim light
What light do cones detect?
Colour, works in bright light
For a new species to be formed, what conditions must be met by all of the offspring?
They must be fertile
What does the term non-coding DNA mean?
Does not carry the information to make a protein
Name the sugar found in DNA nucleotides.
Deoxyribose
What type of bonding is found between complementary base pairs?
Hydrogen bonding
Name the biologically active entities, each of which contains only one type of nucleic acid.
Viruses
Name two locations in eukaryotic cells where only RNA is found
- Ribosomes
- Cytoplasm
Name the tissue in the pancreas that produces insulin
Islets of Langerhans
Name the biochemical pathway common to aerobic and anaerobic respiration.
Glycolysis
In what part of the cell does glycolysis takes place?
Cytosol
During the first stage of photosynthesis, energised electrons enter two pathways, known as pathway 1 and pathway 2. Where do these energised electrons come from?
Chlorophyll
What is the name given to the group of compounds described by this general formula CxH2Oy?
Carbohydrates
What is the role of the anther?
Produces pollen grains that produce male gametes
What is the role of the receptacle?
Forms the base of the flower.
What is the role of the sepal?
- Protects the flower bud before it blooms
- Involved in photosynthesis
- Attracts insects
Explain the term pollination.
-The transfer of pollen from the anther of the stamen to the stigma of the carpel.
Describe how pollen grains develop from microspore mother cells.
- Microspore mother cell diploid
- Divides by meiosis in anther
- To form four haploid microspores which become pollen spores
Describe the further development of a pollen grain to form two male gametes.
- Each pollen grain divides by mitosis
- To form generative nucleus
- Pollen grain matures
- Wall forms
- Generative nucleus divides by mitosis to form 2 male gametes
What happens to the two male gametes during fertilisation?
- One male gamete fuses with the egg to form a diploid zygote
- One male gamete fuses with the two polar nuclei to form a triploid endosperm.
Following fertilisation what part of the flower becomes the seed?
The ovule
Mention two ways in which knowledge of seed dormancy is advantageous.
- Can allow grower to provide optimum storage conditions for seeds
- Can maximise growing season
Explain the term tropism.
A growth response of a plant to a directional stimulus
What is a plant growth regulator?
A chemical that, at very low concentrations affects the development of a plant
What growth regulator ripens fruit?
Ethene
Identify the hormone that regulates a plant’s growth responses to light.
Auxin
What term is used to denote the functional unit of the kidney?
The Nephron
What is the dilute solution produced by the nephron called in the early stages of the process of urine formation?
The glomerular filtrate
Name the hormone which controls urine volume.
Anti- diuretic hormone (ADH)
Where is ADH produced?
The pituitary gland
Which precise area in the kidney does ADH target?
- Collecting duct
- Distal convoluted tubule
One part of the human male reproductive system has both an exocrine and an endocrine function. Name them.
The testes.
Exocrine- produces sperm
Endocrine- produces testosterone
Name two circuits that make up the human circulatory system.
- Systemic Circuit
- Pulmonary Circuit
Which circulatory circuit has blood pumped by the right ventricle of the heart?
Pulmonary circuit
Name the two substances which help maintain the shape of the eye.
- Aqueous humour
- Vitreous humour
Where is the aqueous humour located?
Chamber in front of the lens
Where is the vitreous humour located?
Chamber behind the lens
How did you distinguish between the ventral and dorsal surfaces of the heart?
- Ventral surface is more rounded
- Thick-walled arteries are on ventral surface
Name the site of filtration in the nephron.
Glomerulus/ Bowman’s capsule
Where is the thyroid gland located, what is function and name of the main hormone it produces.
- Neck
- Thyroxine
- Controls rate of metabolism
Where is the thymus gland located, what is function and name of the main hormone it produces
- Behind the breastbone in the upper chest
- Thymosin
- Matures and activates lymphocytes
Where are the adrenals glands located, what is their function and name of the main hormone they produce.
- Top of the kidneys
- Adrenaline
- Fight or flight response
Why does insulin have to be injected?
It is a protein and would be digested if taken orally.
What is genetic engineering?
The artificial manipulation of genes.
State one application of genetic engineering in plants.
-Herbicide resistant plants
State one application of genetic engineering in micro-organisms.
-Production of hormones, eg. insulin
What is meant by the term sex-linked?
The gene controlling a certain characteristic is located on the X (or sex) chromosome
What is the term to describe a person who has a gene for colour blindness but who does not exhibit the condition?
Carrier
