Summary questions 1. Copy and complete the following sentences using the words and numbers below: fertilisation
egg 23 sperm zygote
46
Every human body cell contains ____________ chromosomes, apart from gametes, which contain ____________ chromosomes each. The male gamete is called a ____________. The female gamete is called an ____________. The male and female gametes fuse during ____________ and a single cell called a ____________ is produced.
2. a. Identify the two forms of reproduction.
b. For each form of reproduction, name an example of an animal and a plant that is able to reproduce this way.
3. Copy and complete the following table: Asexual reproduction
Number of parents
Gametes Fertilisation Offspring
Variation introduced?
4. Explain the difference between the terms ‘characteristic’ and ‘trait’. Give an example to support your answer.
5. Genetic material is contained in chromosomes. a. Where in the cell are chromosomes located? b. What chemical do chromosomes contain? c. Name the three scientists who discovered that DNA is shaped like a spiral staircase.
No Characteristics from both parents Two Sexual reproduction
:Fig. 4.14
6. Identify whether the following characteristics are inherited or acquired: a. accent b. hair colour c. ability to drive a car d. eye colour
38 Elements of Science
e. blood type f. hair length g. colour blindness h. muscle definition