Bio P4 Finals 2021
1(a) arthropods
(b) A - oval carapace / jagged edge of carapace / claws same length,
eyes on short stalk
B - Long antennae, abdomen not under carapace, shorter back legs,
hair on claws, eyes on stalks, body is long & coiled
(c) uneven length of chelipeds / claws ; square/rectangular carapace
(d) back hind legs, longer/wider back legs, jagged edge on claws, no
eye stalk
(c)(I) segments
Antennae
Projection over whole of the body
A head and a tail
(c)(ii) Genus (Nereis), diversicolor (species)
2(a) A - fungus
B - virus
C - bacteria
(b) Fungus (largest) , bacteria , virus (smallest) // ACB
(ii) A / fungus & C / bacteria
3(a) A
- cell wall, B - cytoplasm , C - vacuole
(b) produced by photosynthesis in leaves, glucose is converted into
sucrose, travels down in the phloem to the root hair cells
(c) Water - travel through osmosis from high water potential to low
water potential down the concentration gradient through a partially
permeable membrane, without the use of energy
Ions - active transport, moves from low concentration to high conc. Up
the concentration gradient , with the use of energy & carrier proteins
4(a)(I) A - cytoplasm, B - nucleus
(a) (ii) allow substances to go in and out of cell // keeps contents of cell
inside/ forms a barrier between the cell & its surroundings
(iii) irregular shape / rounded shape / not rectangular / no specific
shape
(b) provides a large surface area, more surface for respiration, allows
increased / faster / efficient respiration
(c) mitochondria is the site of aerobic respiration / production of ATP
energy. Liver cell / heart cell is very active and use lots of energy /
respire more, because liver cells are able to use the energy to detoxify
chemicals, heart cells needs energy to pump blood throughout the
whole body. Sperm cells are active / swim towards the egg cell. Sperm
cells have few mitochondria, as they are small. RBC has no
mitochondria, so that it has more space for oxygen, use less energy /
do not actively move