Biology • Year 12 • Module 5 • Lesson 5
Manipulating Reproduction in Agriculture
Lock in the structures, terms and procedures behind selective breeding, artificial insemination, embryo transfer and controlled pollination.
1. Label the artificial insemination & embryo transfer diagram
The diagram below shows how dairy farmers manipulate reproduction in cattle. Write the missing labels into boxes A–H. Each label is taken from the lesson's Key Terms or Cards 1–2. 8 marks Band 3
- A — name of technique (sperm-side) _______________________
- B — material collected from sire _______________________
- C — how many recipient cows it can reach _______________________
- D — main advantage _______________________
- E — name of technique (egg-side) _______________________
- F — material flushed from donor _______________________
- G — role of recipient cow _______________________
- H — genes in the calf come from? _______________________
| Box | Your label |
|---|---|
| A | |
| B | |
| C | |
| D | |
| E | |
| F | |
| G | |
| H |
2. Term–definition match
The nine definitions below are shuffled. In the right-hand column write the matching term from this list: selective breeding, artificial insemination, embryo transfer, controlled mating, controlled pollination, gene pool, surrogate, elite sire, homozygosity. 9 marks Band 3
| # | Definition (shuffled) | Matching term |
|---|---|---|
| 2.1 | The deliberate transfer of pollen from a chosen donor plant to the stigma of a chosen recipient plant. | |
| 2.2 | Placing an embryo collected from one female into the uterus of a second female for gestation. | |
| 2.3 | The total variety of alleles present in a population. | |
| 2.4 | Introducing semen into the female reproductive tract using an instrument rather than by natural mating. | |
| 2.5 | The state of carrying two identical alleles at a gene locus, which rises in heavily inbred lines. | |
| 2.6 | A female that gestates an embryo to which it is not genetically related. | |
| 2.7 | A male of exceptional genetic merit whose semen is widely distributed across many females. | |
| 2.8 | Choosing parents with desirable inherited characteristics so those traits become more common in future generations. | |
| 2.9 | Managing which animals are allowed to reproduce together so that the offspring inherit chosen combinations of traits. |
3. True or false — with correction
Decide whether each statement is True or False. If it is false, rewrite it as a correct statement on the line below. 10 marks (2 per row) Band 3–4
3.1 Selective breeding creates entirely new alleles that did not previously exist in the population. (T / F)
If false, correction:
3.2 Artificial insemination allows a single high-merit bull to sire offspring in many herds without natural mating. (T / F)
If false, correction:
3.3 Embryo transfer changes the genotype of the embryo so that it inherits genes from the surrogate mother. (T / F)
If false, correction:
3.4 Controlled pollination is used to direct inheritance in plants, the way controlled mating is used in animals. (T / F)
If false, correction:
3.5 Heavy use of a small number of elite parents over many generations widens the gene pool. (T / F)
If false, correction:
4. Cloze paragraph — the trade-off summary
Fill each blank with the correct term from the word bank. Use each term once unless marked (×2). 8 marks Band 3–4
Word bank: selective breeding · artificial insemination · embryo transfer · controlled pollination · gene pool · disease · surrogate · uniformity
In animal agriculture, 4.1 __________________ uses semen from chosen sires across many females without natural mating, while 4.2 __________________ moves embryos from a genetically valuable cow into a 4.3 __________________ that carries the pregnancy to term. In plant agriculture, the equivalent technique is 4.4 __________________, which controls which pollen reaches the stigma. Over many generations, 4.5 __________________ deliberately concentrates favoured alleles, which improves productivity and 4.6 __________________ across the herd or crop. The cost of this approach is a narrower 4.7 __________________, which raises homozygosity and can leave the population vulnerable to a single 4.8 __________________ outbreak.
Q1 — Labelled diagram
A: artificial insemination. B: semen (collected from the bull and frozen in straws). C: many recipient cows (one sire serves many females). D: rapid, low-cost spread of elite genetics without natural mating. E: embryo transfer. F: embryo(s) flushed from the donor's uterus after superovulation. G: surrogate / recipient — gestates the embryo but contributes no genes. H: genes come from the elite donor cow and the chosen sire, NOT the surrogate.
Q2 — Term–definition matches
2.1 controlled pollination • 2.2 embryo transfer • 2.3 gene pool • 2.4 artificial insemination • 2.5 homozygosity • 2.6 surrogate • 2.7 elite sire • 2.8 selective breeding • 2.9 controlled mating.
Q3 — True / False with correction
3.1 False. Selective breeding does not create new alleles. It increases the frequency of existing alleles by choosing parents that already carry the desirable traits.
3.2 True. A single high-merit bull can sire offspring across many herds via frozen-semen AI.
3.3 False. The embryo's genotype is fixed at fertilisation by the donor cow and the sire. The surrogate provides only the uterine environment; she contributes no nuclear DNA to the offspring.
3.4 True. Both techniques direct inheritance by choosing which parents pass on alleles — pollination in plants, mating in animals.
3.5 False. Heavy reuse of a small number of elite parents narrows the gene pool, raising homozygosity and the chance of shared vulnerability (e.g. hip dysplasia in pedigree dogs, mastitis susceptibility in Holstein dairy lines).
Q4 — Cloze answers
4.1 artificial insemination • 4.2 embryo transfer • 4.3 surrogate • 4.4 controlled pollination • 4.5 selective breeding • 4.6 uniformity • 4.7 gene pool • 4.8 disease.