2013 january Flashcards
give one environmental factor and one other factor that might affect the number of peas in a pod (2)
✏️ any correct named physical environmental condition, e.g. light / water / rain / temperature / minerals / nutrients / space (between plants)
✏️ genes / inheritance OR ✏️ any correct named biotic factor e.g. predation / disease
it is important that carbon is cycled through living things.
after he has picked the peas, the gardener puts the dead pea plants onto a compost heap. over the next few months, the carbon in the carbon compounds from the pea plants is returned to the air. describe how (4)
✏️ microorganisms / bacteria / fungi / decomposers / detritus feeders / named
✏️ decompose / rot / break down / decay / digest
✏️ (these organisms) respire
✏️ (decay / respiration / microorganisms etc / releases carbon dioxide
name the glands where the eggs are made and the small gland in the brain which produces fsh (2)
✏️ ovaries and ✏️ pituitary gland
how does fsh move from the pituitary gland to the ovaries (1)
in blood (stream)
a woman is not able to become pregnant. The woman does not produce mature eggs, so she decides to have In Vitro Fertilisation (IVF) treatment. which two hormones will help the woman produce and release mature eggs? (1)
FSH and luteinising hormone (LH)
describe how the mature eggs are used in IVF treatment so that the woman may become pregnant (3)
✏️ fertilised OR ✏️ reference to sperm
✏️ form embryos / ball of cells or cell division
✏️ (embryo) inserted into mother’s womb / uterus
suggest one reason why IVF clinics have been set targets to reduce multiple births (1)
✏️ multiple births lead to low birth weight
✏️ multiple births cause possible harm to mother / fetus / embryo / baby / miscarriages
a student is given a tube containing a liquid nutrient medium. The medium contains one type of bacterium. the student is told to grow some of the bacteria on agar jelly in a Petri dish. describe how the student should prepare an uncontaminated culture of the bacterium in the Petri dish. you should explain the reasons for each of the steps you describe (6)
examples of biology points made in the response:
pre-inoculation
✏️ petri dish and agar sterilised before use
✏️ to kill unwanted bacteria
✏️ inoculating loop passed through flame / sterile swab
✏️ to sterilise / kill (other) bacteria
inoculation
✏️ loop/swab used to spread/streak bacterium onto agar
allow other correct methods, eg bacterial lawns
✏️ lid of Petri dish opened as little as possible
✏️ to prevent microbes from air entering
post-inoculation ✏️ sealed with tape ✏️ to prevent microbes from air entering ✏️ incubate ✏️ to allow growth of bacteria
there are areas of agar jelly where no bacteria will grow in a petri dish with agar, why? (1)
bacteria killed / destroyed
why might a strong disinfectant be the best for using around the home, give one reason for and one reason against (2)
✏️ for: largest area / space where no bacteria are growing
✏️against: (need more evidence as) D may be harmful to people / animals / surfaces or may work differently with different bacteria or disinfectants may be different concentrations or may not last as long
what term is used to describe organisms that can survive in severe conditions such as very high concentrations of salt solution? (1)
extremophile(s)
why are two types of periwinkle likely to compete with each other to the greatest extent? (1)
both live in the same habitat / area / named area
the small periwinkle can survive much nearer to the high tide level than the flat periwinkle. suggest two reasons why the flat periwinkle cannot survive near to the high tide level (2)
✏️ would have wrong food
✏️ would otherwise be exposed to (specific) predators
✏️ cannot tolerate extended exposure to air or reduced submersion in seawater
✏️ cannot tolerate high salt concentration (in rock pools)
✏️ cannot compete with small periwinkle
give two ways other than producing antibodies that white blood cells protect us against pathogens (2)
✏️ (produce) toxins / poisons
✏️ (cause) damage to cells
what does a doctor inject into a child when vaccinating them to make them immune to measles? (2)
dead / inactive / weakened (measles) pathogen / virus
