BTEC APPLIED SCIENCE UNIT 1 BIOLOGY
EXAM WITH CORRECT ANSWERS.
Explain why palisade cells are closely packed together - correct Answers -
To form a continuous layer in the leaf
Explain why palisade cells have a large vacuole - correct Answers -To
maintain turgor (pushes against the cell wall to maintain rigid shape)
Describe the adaptations of a root hair cell - correct Answers -Root hair
shape
Large vacuole
Thin cellulose walls
Explain why root hair cells have an elongated section known as the root
hair - correct Answers -Increased surface area for maximum movement of
water into the cell
Explain why root hair cells have a large vacuole - correct Answers -
Contains cell sap with low water potential to encourage water into the cell
Explain why root hair cells have thin cellulose walls - correct Answers -
Encourage movement of water and minerals into the cell. Short distance for
osmosis and diffusion
Describe the adaptations of a sperm cell - correct Answers -Lots of
mitochondria
,Shaped head containing acrosome (with enzymes)
Haploid nucleus
Tail for movement
Explain why a sperm cell has an undulipodium (tail) - correct Answers -To
allow the sperm to move to the egg
Explain why sperm cells contain large numbers of mitochondria - correct
Answers -To produce the large amounts of energy needed for movement
Explain why sperm cells have a shaped head - correct Answers -To push
through the protective layer of the egg cell
Explain why sperm cells contain acrosome in the head - correct Answers -
To digest the zona pellucida to allow entry into the egg cell
Explain why sperm cells have a haploid nucleus - correct Answers -
Contains half the genetic material.
Describe the adaptations of egg cells - correct Answers -Contains a haploid
nucleus
Protective outer layer (zona pellucida)
Corona radiata
Explain why egg cells have a haploid nucleus - correct Answers -Contains
half the genetic material
, Explain why egg cells have a zona pellucida (protective layer) - correct
Answers -Protects the cell and only allows one sperm cell to enter.
Explain why egg cells have a corona radiata (two or three layers attached to
the zona pellucida) - correct Answers -Contains all of the proteins needed
to develop the fertilised cell
Describe the adaptations of red blood cells - correct Answers -No nucleus
(mammals only)
Biconcave shape
Haemoglobin
Flexible
Explain why red blood cells don't contain a nucleus - correct Answers -
Allows for more oxygen to be carried in the cell
Explain why red blood cells have a biconcave shape - correct Answers -
Increased surface area for gas exchange
Explain why red blood cells contain haemoglobin - correct Answers -To
bind with the oxygen in order for it to be carried around the body
Explain why red blood cells are flexible - correct Answers -To fit through
the tiny blood vessels such as capillaries
EXAM WITH CORRECT ANSWERS.
Explain why palisade cells are closely packed together - correct Answers -
To form a continuous layer in the leaf
Explain why palisade cells have a large vacuole - correct Answers -To
maintain turgor (pushes against the cell wall to maintain rigid shape)
Describe the adaptations of a root hair cell - correct Answers -Root hair
shape
Large vacuole
Thin cellulose walls
Explain why root hair cells have an elongated section known as the root
hair - correct Answers -Increased surface area for maximum movement of
water into the cell
Explain why root hair cells have a large vacuole - correct Answers -
Contains cell sap with low water potential to encourage water into the cell
Explain why root hair cells have thin cellulose walls - correct Answers -
Encourage movement of water and minerals into the cell. Short distance for
osmosis and diffusion
Describe the adaptations of a sperm cell - correct Answers -Lots of
mitochondria
,Shaped head containing acrosome (with enzymes)
Haploid nucleus
Tail for movement
Explain why a sperm cell has an undulipodium (tail) - correct Answers -To
allow the sperm to move to the egg
Explain why sperm cells contain large numbers of mitochondria - correct
Answers -To produce the large amounts of energy needed for movement
Explain why sperm cells have a shaped head - correct Answers -To push
through the protective layer of the egg cell
Explain why sperm cells contain acrosome in the head - correct Answers -
To digest the zona pellucida to allow entry into the egg cell
Explain why sperm cells have a haploid nucleus - correct Answers -
Contains half the genetic material.
Describe the adaptations of egg cells - correct Answers -Contains a haploid
nucleus
Protective outer layer (zona pellucida)
Corona radiata
Explain why egg cells have a haploid nucleus - correct Answers -Contains
half the genetic material
, Explain why egg cells have a zona pellucida (protective layer) - correct
Answers -Protects the cell and only allows one sperm cell to enter.
Explain why egg cells have a corona radiata (two or three layers attached to
the zona pellucida) - correct Answers -Contains all of the proteins needed
to develop the fertilised cell
Describe the adaptations of red blood cells - correct Answers -No nucleus
(mammals only)
Biconcave shape
Haemoglobin
Flexible
Explain why red blood cells don't contain a nucleus - correct Answers -
Allows for more oxygen to be carried in the cell
Explain why red blood cells have a biconcave shape - correct Answers -
Increased surface area for gas exchange
Explain why red blood cells contain haemoglobin - correct Answers -To
bind with the oxygen in order for it to be carried around the body
Explain why red blood cells are flexible - correct Answers -To fit through
the tiny blood vessels such as capillaries
