Life Sciences
Grade 12
June Exam_2025
Resources: DBE_EC/JUNE2022, @IMPAQ JUN 2022, @IMPAQ JUN 2021, Revision booklet _ Life Sciences Mind the Gap Study Guide, DBE Exam
Guideline 2021_ Self Study Guide 4.
This information/answers are from the memorandum (there are more possible answers).
Some information is repeated - I want to show you the different ways in which the same
information is asked. I encourage you to answer the calculation/illustration questions.
Good luck: Juffrou Ansie
CONTENT
1. DNA: THE CODE OF LIFE
2. MEIOSIS
3. HUMAN REPRODUCTION
4. GENETICS AND INHERITANCE
5. RESPONDING TO THE ENVIRONMENT (HUMANS)
6. HUMAN ENDOCRINE SYSTEM AND HOMEOSTASIS IN HUMANS
@Juffrou_Ansie
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SECTION A
The central nervous The central nervous system is made up of the brain and
system spinal cord.
Vivipary Vivipary involves the development of the young inside
the uterus of the mother and where it receives nutrients
through the placenta
Phenotype Physical appearance of an individual
Homologous Maternal and paternal chromosomes that have the same
shape and size are paired together but differ in genetic
material.
Stem cells Undifferentiated animal cells that have the ability to
change into any cell type.
Epididymis The sperm cells in humans temporarily stored here
Cerebrum A patient experiences slight visual and speech
disturbance after a serious head injury. This section of the
brain was possibly damaged.
The diagram shows the blood groups of individuals in a
family.
Both parents have the allele for blood group O.
Contraceptive pills Contraceptive pills which prevent pregnancy are likely to
contain high levels of only progesterone.
Increased heart rate An effect of the sympathetic nervous system
Internal fertilisation The type of fertilisation where the eggs are fertilised inside
the body of the animal
Allantois A structure involved in gaseous exchange in the amniotic
egg.
35 °C Healthy sperm are produced at a temperature of 35 °C
Umbilical vein A blood vessel in the umbilical cord that transports
nutrients to the foetus
Mitochondrion Organelle outside the nucleus of animal cells that contain
DNA
Pinna The part of the ear that directs sound waves into the
external auditory canal
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Acrosome The structure in the head of a sperm containing digestive
enzymes
Puberty The stage when secondary sexual characteristics
develop in males and females
Chromatin network The network of genetic material found in the nucleus
during interphase
Amniotic egg The type of egg produced by reptiles that has extra-
embryonic membranes
Watson and Crick Discovered the structure of the DNA molecule
Altricial Reproductive strategy in birds where hatchlings are
helpless and unable to move and feed themselves
Placenta The part of the female reproductive system that acts as a
micro filter during pregnancy
Precocial (development) The type of development strategy that refers to species
where the young that are hatched or born are almost
fully developed and are immediately mobile
Crista A receptor in the semi-circular channels of the ear that
observes the change in speed or movement of the head.
Ejaculation The release of sperm cells by the penis is called
ejaculation.
Testosterone The hormone produced by the testes.
Oxytocin The hormone released during the labour process that
helps with muscle contractions
Pituitary gland / The gland in the body which is also known as the ‘master
Hypophysis gland’.
Ribose sugar The sugar molecule found in RNA
Rod Photoreceptors in the eye that are stimulated at low
intensity, giving rise to white and black vision.
Astigmatism Visual defect due to the uneven curvature of
the cornea of the eye
Binocular vision The ability to focus on an object with both eyes
Stem cells Cells that divide and differentiate into almost any type of
tissue in the human body
Multiple sclerosis A progressive degenerative disease of the brain and
spinal cord
Autonomic nervous Nervous system controlling internal organs and glands
system
@Juffrou_Ansie
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DNA: THE CODE OF LIFE
The diagram below shows the process of protein synthesis. @IMPAQ JUN2021
Identify the following:
a) Structure Q
b) Molecule R
c) Nitrogenous base S
d) Structure W
a)
b)
c)
d)
The sequence of the anticodon V.
The table below shows the RNA codons that code for different amino acids.
@Juffrou_Ansie