B13 Reproduction Flashcards
Asexual reproduction needs only one…
parent.
Asexual reproduction does not involve production of a…
gamete.
gamete = sex cell, e.g. sperm or egg
In asexual reproduction, the daughter plant is called a…
[Hint: begins with ‘c’]
clone.
A red flowered plant is bred with a white flowered plant. All the offspring are red flowered. This shows that the red colour is due to:
a) A dominant allele
b) A recessive allele
c) An environmental factor
a) A dominant allele
The red flowered parent must have been RR and the white flowered parent must have been rr. The offspring would all be Rr meaning the dominant R allele for red flowers is still expressed.
A red flowered plant is bred with a white flowered plant. All the offspring are red flowered. The offspring are then bred and the second generation offspring have a mixture of red and white flowered plants. This shows that the white colour is due to:
a) A dominant allele
b) A recessive allele
c) An environmental factor
b) A recessive allele
The red flowered parent must have been RR and the white flowered parent must have been rr. The offspring would all be Rr. When the offspring are bred their second generation offspring would have been a mixture of RR, Rr and rr, meaning the recessive r allele for white flowers is now expressed in the rr offspring.
How are genes from parents passed to their offspring in sexual reproduction?
The parents produce gametes (sex cells) that contain DNA from each parent (a half set of chromosomes). The gametes fuse to form a zygote containing DNA from both parents (a full set of chromosomes) which divides and grows to form the baby.
How many chromosomes does a human gamete (sex cell) contain?
23 chromosomes
How many chromosomes does a normal human cell contain?
46 chromosomes (23 pairs)
How many chromosomes does a human zygote (fertilised egg) contain?
46 chromosomes (23 pairs)
How many chromosomes does a diploid human cell contain?
46 chromosomes (23 pairs)
How many chromosomes does a haploid human cell contain?
23 chromosomes (half a diploid cell)
The sex chromosomes for a male are:
a) XX
b) XY
b) XY
The sex chromosomes for a female are:
a) XX
b) XY
a) XX
If a couple already have three sons, what is the probability their next child will be a girl?
a) 0%, b) 25%, c) 50%, d) 75%, e) 100%
c) 50%
A fertilised egg (zygote) has ____ of genetic information.
Complete the sentence with:
a) one set
b) two sets
c) half a set
b) two sets
A fertilised egg (zygote) divides to form an embryo by a process called…
mitosis.
Give one environmental factor and one other factor that might affect the number of peas in a pod on a pea plant.
Physical: e.g. light, temperature, rain, nutrients/minerals
Other: e.g. genes, disease
Are the sex chromosomes YY possible?
No.
The number of chromosomes in a gamete (sex cell) is ____ in body cells.
Complete the sentence with:
a) the same number as
b) half the number
c) twice the number
b) half the number
Gametes are produced by ____.
Complete the sentence with:
meiosis / mitosis / fertilisation
a) meiosis
Our understanding of how genes are inherited is mostly due to the work of ____.
a) Darwin
b) Lamarck
c) Mendel
d) Galileo
e) Bieber
c) Mendel
A tall plant is bred with a short plant of the same species. All the offspring are tall.
T = allele for tall (dominant) t = allele for short (recessive)
This shows that the original tall plant was
a) TT
b) Tt
c) tt
a) TT
T = allele for tall (dominant) t = allele for short (recessive)
Draw a punnet square for a Tt tall plant crossed with a tt short plant.
What is the ratio of tall to short offspring?
a) 1:1
b) 2:1
c) 3:1
d) 1:2
a) 1:1
T = allele for tall (dominant) t = allele for short (recessive)
Two short plants were crossed. This cross produced 100 offspring.
The expected offspring would be
a) 100 short plants
b) 50 tall plants and 50 short plants
c) 75 tall plants and 25 short plants
a) 100 short plants
