Year 10 Genetics Practice Quiz 5 Solution
1. Give the functions of the following parts of the male reproductive system.
urethra
carry semen
testes
produce sperm
seminal vesicle
produce seminal fluid that makes up part of semen
vas deferens
carry sperm cells
scrotum
hold the testes outside the body
prostate gland
excretes a fluid that makes up part of semen
2. Give the functions of the following parts of the female reproductive system.
ovaries
store eggs (doesn't produce the eggs)
vagina
stimulate the penis during intercourse and pass
the foetus during birth
cervix
allow the flow of menstrual blood from the uterus
into the vagina and direct the sperm into the
uterus
uterus (womb)
provide a place for the foetus to grow
fallopian tubes
carry ova
3. How is fertilisation defined?
a) One sperm cell penetrating the ovum and combining their DNA
b) The race between X and Y sperm to determine sex in humans in humans
c) The cell formed from the combination of the sperm and ovum implanting on the wall of the uterus
d) The production of sperm in the testes
4. What happens to the number of chromosomes in fertilisation?
a) It halves
b) It doubles
c) It stays the same
d) Nothing
5. Where is DNA found in humans?
In the nucleus of every cell except mature red blood cells.
6. Describe the structure of DNA.
DNA is a double helix. It is like a ladder that is twisted into a spring shape. The rungs of the ladder are
pairs of DNA bases. The sides of the ladder alternating phosphate and sugar units.
7. Define the word 'gene'.
A gene is a section of DNA that codes for a particular characteristic.
8. Define the word 'allele'.
A variety of a particular gene.
9. Define the word 'chromosome'.
Thread-like pieces of DNA.
10. Which of the following alleles are dominant?
a) The allele for brown eye colour (B) and the allele for haemophilia (Xh)
b) The allele for blue eye colour and the allele for haemophilia (Xh)
c) The allele for red coat colour in cows (R) and the allele for white coat colour in cows
d) The allele for the rheus factor (R) and the allele for brown eye colour (B)
11. Which condition is a recessive condition (needing two copies of an allele) to be expressed?
a) Rh negative blood type
b) Haemophilia in females
c) Brown eyes
d) Blood type A
12. What word is used to described a section of a DNA that codes for a particular characteristic?
gene
13. DNA must be replicated when cells reproduce because the daughter cell needs an identical copy of
the DNA. What are the three steps involved in DNA replication?
Step 1. Unwind and unzip the DNA. Step 2. Add the complementary nucleotides. Step 3. Rewind the
DNA.
14. What is a mutation?
a) A piece of DNA that has become cancerous
b) An X-man or X-woman
c) A change in the DNA sequence produced by a DNA copying error
d) A change in the DNA sequence that gives rise to a new species
15. Which of the following is true of mutations? Mutations:
a) are always dangerous
b) are generally negative but very occasionally beneficial
c) happen every time DNA replicates
d) mean automatic death
15. Which of the following is an example of a geneotype?
a) XHY
b) I^O
c) Y
d) Roan coat in cattle
16. Which of the following is an example of a phenotype?
a) XHY
b) IO
c) Y
d) Roan coat in cattle
17. Name four phenotypes did Gregor Mendel investigated in his experiments crossing pea plants.
seed shape (round or wrinkled)
seed colour (yellow or green)
pod shape (inflated or constricted)
pod colour (yellow or green)
flower colour (purple or white)
flower position (axil or terminal)
stem length (long or short)
18. What three things did Medel conclude from his experiments?
The inheritance of each trait is determined by "units" or "factors" (now called genes) that are passed
on to descendants unchanged.
An individual inherits one such unit from each parent for each trait.
A trait may not show up in an individual but can still be passed on to the next generation.
19. Where is DNA located?
a) In the nucleus of cells
b) In the nucleus of atoms
c) In the heart
d) In the blood
20. Which invention led to the discovery of the location of DNA, including the chromosomes?
microscope
21. Which scientists used X-ray crystallography to discover the structure of the DNA molecule?
Watson and Crick
22. Describe IVF.
IVF stands for in-vitro fertilisation. Sperm and eggs are donated then fertilised in a glass straw. The
fertilised eggs grow into an embryos. Several embryos are implanted into a woman's uterus.
23. Describe how Dolly the sheep was cloned.
An ovum and a somatic (regular body) cell were obtained from a sheep. The nucleus was removed
from the somatic cell. The nucleus was removed from ovum and then inserted into the ovum. The
ovum was electrically stimulated to make it start to divide to produce an embryo. The embryo was
then implanted into the uterus of another sheep.