pp 42 2019 Flashcards
State 5 features that are common to all arthropods.
exoskeleton
segmented, limbs
pairs of, limbs
segmented (body);
bilateral body symmetry ;
state 3 features of arachnids
4 pairs of legs
fused head and thorax / cephalothorax
(pedi)palps
Explain the term adaptive feature [4]
inherited feature controlled by gene(s) / allele(s)
functional feature ;
increase chances of survival
increases chance of reproducing (to leave offspring)
DNA can be extracted from the webs of spiders. This DNA can be used to identify the species of spider that made the web, and the species of prey caught in the web.
Explain how DNA extracted from spider webs can be used to identify different species. [4]
identification can be done using: base, sequences in DNA / genes
each species, has unique genes ;
compared with reference DNA of known species ;
if it matche with DNA from known species then DNA is from that species OR closely related species
Many species of spider are thought to be endangered.
State three reasons why animal species such as spiders become endangered. [7]
hunting / collecting / AW ;
pesticides
loss of habitat
disease
increase in predator(s) ;
climate change
not enough food
Draw a circle around one vascular bundle on Fig. 2.1. Label the xylem in the vascular bundle with the letter X.
any shape drawn that includes one whole vascular bundle including all of the xylem and phloem with or without sclerenchyma ; label line from X to xylem in any of the vascular bundles ;
Fig. 2.1. Explain how the cells in area Y are able to support the stem so that it stays upright. [5]
cells, contain (much) water / have high water potential ;
water absorbed, by osmosis / down water potential gradient ;
cells, are turgid / have a turgor pressure ;
cell contents / vacuole / cell membrane, pushes out (against cell wall) ;
cell wall does not stretch
Table 2.1Describe and explain the effect of removing the phloem on the translocation of sucrose in plants Q, R, S and T. 6
Q sucrose is in shoot and root ;
T no, sucrose in shoot or root ;
R sucrose in root only
S sucrose / 13C, in shoot only
no transport of where phloem is removed
phloem transports (sucrose) in both directions
what do cells in the lining of the stomach secrete
gastric juice
what does gastric juice contain [2]
hydrochloric acid and pepsin.
State roles of hydrochloric acid in the stomach. [3]
provides suitable pH for enzyme action ;
activates enzyme / pepsin ;
kills pathogens
Describe the function of pepsin.
chemically digests protein to amino acids ;
Define the term assimilation [2]
movement of digested food molecules into cells
food molecules become part of cells
There are stem cells in the epithelial tissue that forms the lining of the stomach. Explain why these stem cells are necessary [5]
stem cells divide by mitosis ;
form specialised cells in stomach ;
to replace cells (in the lining of stomach) ;
cells are worn away from the surface of the stomach ;
for repair of any damage to tissues ;
The epithelial cells of the small intestine have many microvilli. State the role of the microvilli [2]
increase surface area ;
for absorption of nutrients
Fig. 3.1 Calculate the percentage increase in the average number of bacteria attached to epithelial cells from 45 minutes to 75 minutes.
54(%)
one mark for correct readings (78 minutes and 120 minutes)
one mark for correct calculation
one mark for whole number correctly rounded
Explain how the human gas exchange system is protected against pathogens. [6]
mechanical / chemical, barriers
nasal hairs trap pathogens
mucus traps pathogens
cilia move mucus upwards ;
coughing / sneezing / swallowing ;
phagocytes / phagocytosis
Tuberculosis (TB) is a transmissible disease caused by a bacterial pathogen. The spread of this disease can be controlled by vaccination.
Explain how vaccination provides a defence against transmissible diseases [6]
introduces harmless form of pathogen
stimulates an immune response ;
lymphocytes produce antibodies ;
(lymphocytes develop into) memory cells ;
memory cells, give long-term immunity / can produce antibodies (at a later time) ;
respond quickly when an infection (of the same pathogen) occurs / before symptoms occur ;
TB is a disease that can be treated with antibiotics. HIV infection cannot be treated with antibiotics. Explain why viral diseases cannot be treated with antibiotics. [6]
idea that viruses have no antibiotic targets ;
viruses, are not alive/ not cells ;
no cell membrane or cell wall ;
no protein synthesis;
no metabolism / do not respire ;
viruses are inside (host) cells
Describe the differences between the percentages of males and females in country A that smoke as shown in Fig. 4.1. [3]
more males smoked than females
decrease in percentage of males smoking is greater than in females
peak for percentage of men smoking occurred earlier
fig 4.2 Discuss the evidence for this statement:
‘The changes in the percentage of the population that smoke tobacco, and the deaths from lung cancer per 100000, follow the same trends in males and in females.’
Use the information for country A [4]
percentage of men and women that smoke increases and decreases ;
numbers of deaths from lung cancer in both groups increases and decreases ;
both show lag between peak smoking and peak deaths from lung cancer ;
country A shows, same time 40-year gap, between peaks for smoking and deaths from smoking ;
Discuss the evidence for this statement:
‘The changes in the percentage of the population that smoke tobacco, and the deaths from lung cancer per 100000, follow the same trends in males and in females.’
Use the information for country B in Fig. 4.2 in your answer
percentage of men and women who smoke has decreased (overall) ;
numbers of deaths from lung cancer in both groups increase ;
Discuss the evidence against this statement:
‘The changes in the percentage of the population that smoke tobacco, and the deaths from lung cancer per 100000, follow the same trends in males and in females.’
Use the information for country B in Fig. 4.2 in your answer [3]
against from B percentage female smokers, fluctuates but no fluctuation in men ;
numbers of deaths in men increase (continually), whereas deaths in females does not ;
country B may show the same but no data from before 1950 ;
Describe and explain how the features of the flower shown in Fig. 5.1 are adaptations for wind-pollination. 5
anthers / stamens / filaments / stigma, hang outside (the flower) ;
large, anthers, produce large quantities of pollen ;
idea that anthers, easily release pollen ; ‘
stigma has, feathery surface / large surface area, to catch pollen ;
bracts are, small inconspicuous ;
Fig. 5.1 what is A
Bracts
Fig. 5.1 what is B
stigma
Fig. 5.1 what is C
anthers
Fig. 5.1 what is D
filament
State one letter in Fig. 5.1 that identifies a structure where meiosis occurs.
C, anther
Wheat has flowers similar to those in Fig. 5.1, but reproduces by self-pollination. Explain the consequences of self-pollination for a population of plants. [6]
no agent of pollination needed ;
little wastage of pollen ;
reduced variation ;
increased competition between plants (bc they have the same adaptations) ;
little ability to adapt to changing conditions ;
an infectious disease can kill all of the population
Outline factors, other than plant diseases, that can cause famines. [6]
drought
flooding ;
fire ;
insect pests ;
unequal distribution of food ;
soil erosion / desertification
Fig. 5.2 Suggest how plant breeders make sure that the plants that they use for step 3 are rust-resistant. [3]
expose the plants to stem rust
find out if plants have DNA for rust resistance ;
only use those plants that show no symptoms
Fig. 5.2 Suggest why step 3 is repeated for many generations before the new rust-resistant variety is made available for farmers to grow. [5]
to increase the, numbers of plants / population ;
incorporate more genes from the high yield variety ;
check that the plants keep their resistance to rust ;
check the plants grow well in field conditions ;
make sure the plants are, pure-breeding / homozygous
State features of monocotyledons that can be used to distinguish them from dicotyledons. [5]
one cotyledon / embryonic leaf
parallel-veined leaves
petals in multiples of three
fibrous roots / adventitious roots
scattered vascular bundles in stem
Complete Table 6.1 by naming the processes labelled A in Fig. 6.1.
photosynthesis
Complete Table 6.1 by naming the processes labelled B in Fig. 6.1.
combustion
Complete Table 6.1 by naming the processes labelled C in Fig. 6.1.
respiration
Complete Table 6.1 by naming the processes labelled D in Fig. 6.1.
fossilisation
Carbon dioxide is a greenhouse gas. Greenhouse gases trap …………. in the atmosphere.
heat / infra-red radiation
……….is the most common greenhouse gas in the atmosphere.
Water vapour
Another greenhouse gas is methane which is released from [6]
decomposition
rice farming
livestock
landfill
faeces
forest fires
Carbon dioxide and methane released from human activities over the past 200 years have contributed to the
enhanced greenhouse effect
acid rain is caused by [3]
sulfur dioxide
sulfur trioxide
nitrogen oxide
One source of pollution in both aquatic and terrestrial ecosystems is
non-biodegradable plastics
Scientists think that the pattern on the bodies of the spiders is an adaptive feature. How could this feature be adaptive? 5
camouflage
warning signal
scares predators
lure for prey
sexual attractant
