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1. We ------- some features from our parents. (lesson 33a)
2. Other features are the effect of our -----------. (33a)
3. Give an example of variation that is clear-cut. (33a)
4. What sort of things vary gradually? (33a)
5. What are the thread-like structures found in the nucleus? (33b)
6. How many of these thread-like structures are there in most human cells? (33b)
7. What is it that controls features like our eye colour? (33b)
8. What chemical makes up the genes? (33b)
9. How many genes are there for each feature that is inherited? (33c)
10. If a brown gene is 'stronger' than a white gene, we say that it is --------. (33c)
11. Genes giving a 'weaker' message are called ---------. (33c)
12. What is meant by selective breeding? (33d)
13. How have new breeds of cattle 'improved' upon older breeds? (33d)
14. What is artificial insemination? (33d)
15. Eggs from the best cows can be fertilised with bull sperm in a test-tub. The fertilised eggs are put into another cow. What are these called? (33d)

ANSWERS

1. Inherit.
2. Environment.
3. Eyecolour/hair colour/tongue rolling/left-handed or right-handed.
4. Weight, height, length.
5. Chromosomes.
6. 46.
7. Genes.
8. DNA.
9. 2.
10. Dominant.
11. Recessive.
12. We breed in features that we want and breed out features that we don't want.
13. They produce more milk and more beef.
14. Sperm can be taken from the best bulls and injected by a vet into the best cows.
15. Embryo transplants.