Perguntas que eu errei Flashcards
(ignora o resto)
Suggest why a protective substance is necessary in the intestines. (2)
- protect the intestine from pathogens
- physical damage by food passing through intestine
What is the ileum?
an organ
Define the term chromosome. (2)
strand of DNA (1) that contains genetic material (2)
Describe the roles of FSH and LH in the menstrual cycle. (4)
- FSH stimulates, development and maturation of follicles
- FSH stimulates, development and maturation of an egg
- FSH stimulates release of oestrogen from ovary
- LH stimulates ovulation
- LH stimulates release of progesterone (corpus luteum)
Describe the changes that occur in the lining of the uterus during one menstrual cycle. (3)
- loss of lining at the beginning of the cycle
- thickening of lining after loss, 2nd week
- last 2 weeks, after ovulation: thickness of lining remains constant
Outline how the hormones in contraceptives act as a method of birth control. (3) (mari nao precisa saber disso, saiu do syllabus)
- contraceptives contain progesterone
- prevents release of FSH/LH
- prevents, development of follicles
- prevents ovulation
Function of effectors. (1)
carry out response
Function of receptors. (1)
detects the stimulus
Which organ produces bile? (1)
liver
Describe graph for enzyme activity x temp.
decrease after optimum is steeper than increase
line meets x axis at end
Explain the effect of a lack of magnesium ions of the colour of plant leaves. (2)
yellow (1) since magnesium is required for making chlorophyll (2)
Explain why the sequence of amino acids is important in the production of receptor molecules for neurotransmitters. (2)
- the sequence of amino acids determines the shape of the protein
- a complementary shape required for the receptor molecule to bind to neurotransmitter
Describe how artificial selection differs from natural selection. (3)
- humans choose desired features
- humans choose individuals to reproduce
- selection not influenced by environment
- decreases genetic variation
- faster
- for economic reasons
State two other sources, besides mutation, for genetic variation in populations. (2)
meiosis/crossbreeding
random fertilisation
Explain why vitamin D is important for the nutrition of children. (3)
- needed for development of bones
- needed for development of teeth
- prevents rickets
Define the term ‘transmissible disease’. (2)
disease is caused by a pathogen (1) which is passed from one host to another (2)
Explain why women should be vaccinated against rubella before they reach reproductive age. (4)
- rubella is caused by a virus
- virus can cross the placenta
- and can affect embryo fetus
- can cause serious damage to baby
- vaccination stimulates long-lasting active immunity in mother, so immunity is gained before they become pregnant (2)
Explain why the rate of photosynthesis will decrease if the humidity in the apparatus becomes very low. (3)
- air becomes dry
- diffusion gradient for water vapour increases
- increased rate of transpiration
- stomata close
- CO2 cannot enter
Explain why the rate at which CO2 is used in photosynthesis is greater than the rate of its uptake. (2)
- carbon dioxide produced in respiration
- plants respire all the time
- carbon dioxide released by cells is used in photosynthesis
Discuss the advantages of growing crops in glasshouses. (6)
- glasshouses can maintain optimum conditions for
photosynthesis - maintain optimum light intensity
- by using artificial lights
- maintain optimum temperature
- heater/cooling
- can use CO2 enrichment
by burning fuels - supply of nutrients and minerals
- herbicides not required
- control of pollinators for selective breeding
Outline the process of artificial insemination (3).
- collect semen
- selecting of sperm
- determine when female is about to ovulate
- insert sperm into female
State two main features of fungal cells that are used to distinguish them from cells of prokaryotes. (2)
- nucleus
- mitochondria
List 2 nutrients that need to be added to a fermenter to produce penicillin. (2)
- water
- glucose
- amino acids
Explain why the nutrients are sterilised before they are added to the fermenter. (1)
to make sure no other microogranisms can grow
Explain why the fermenter has a gas outflow pipe. (2)
so that waste gases like CO2, produced during fermentation and respiration, can escape
reduce pressure
Describe how acid rain destroys forests. (3)
- acidifies soil
- acidified soil causes leaching
- damage leaves
- affects ability of roots to absorb mineral ions
Mutations are always inherited in single-celled organisms that reproduce asexually but are not always inherited in organisms that reproduce sexually. Explain why. (4)
- mutations are found in the DNA
- asexual reproduction offspring are genetically identical to the parent
- so any existing mutations in parent DNA will be inherited
- sexual reproduction involves two parents
- mutation will only be in some of the gametes
- meiosis does not result in genetically identical cells
Suggest why amphibians are vulnerable to pollutants such as acid rain. (2)
- permeable skin
- they have fragile/thin gills
- part of their life only exists in water
Describe the structure of a villus and its role in the alimentary canal. (6)
- lacteals absorb fatty acids and glycerol
- lymphatic vessel, returns fats to blood
- epithelial cell has microvilli
- increasing the surface area for absorption
- epithelial layer one cell thick for short diffusion distance
- epithelial layer is where break down of maltose into glucose occurs
Discuss the possible disadvantages of people changing the genes in a plant. (3)
- cross-pollinate into wild populations
- expensive GM seeds
- ethical concerns
- reduced natural biodiversity
Predict and explain the effect of high humidity on the stomata. (3)
- stomata will take longer to close
- reduced water vapour concentration gradient
- so the guard cells do not lose water as quickly
- guard cells stay turgid
State two types of cell membrane proteins. (2)
carriers
enzyme/maltase
Explain how bacteria become resistant to antibiotics. (5)
- random mutations in some bacteria
- bacteria with resistance survive and reproduce
- passing on their resistant gene
- increase in frequency of resistant gene in population
- natural selection/becoming better adapted for new environment
