CELL DIVISION

Test Yourself!

Test Yourself!

Cells

  • Mitosis is the process in which genetically identical cells are formed.
  • Mitosis is used for growth and to make replacement cells.
  • Meiosis creates gametes.
  • Gametes only contain one set of chromosomes.
  • Fertilisation is the process in which an egg and a sperm fuse together to form a zygote. This then divides by mitosis.
  • Alleles are different versions of the same gene.
  • An allele can be either recessive or dominant.
  • Gender is determined by two alleles: X and Y.
  • Due to the fact that everyone (apart from identical twins) has different DNA, DNA finger printing can be used to catch criminals.
  • Mendel put forward the idea of separately inherited factors.
  • Genetic diagrams show how alleles can create different characteristics.
  • Genetics disorders, like cystic fibrosis, are caused by genetic mutations.
  • Embryo screening can be used to check for genetic disorders.

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TEST IT!

1. Show dogs are bred for particular characteristics. Complete the sentences choosing from the words below.

characteristic / chromosomes / genes / gamete

a) The colour of dog’s fur is called a ____________________

b) The colour of its fur is controlled by ____________________

c) A pair of ___________________ is found in all cells apart from gametes.

2. In Mendel’s pea plant experiments:

From his experiments Mendel concluded that flower colour was inherited.

a) Which colour is dominant?

b) What are different versions of the same gene called?

c) How does each new generation inherit factors?

3. Sex chromosomes, X and Y, control whether a human is male or female.

a) Complete the Punnett square below which represents sex inheritance.

b) A couple already has two girls. What are the chances that their next child will be a boy?

ANSWERS

1.

a) …characteristic

b) …genes

c) …chromosomes

2.

a) Red

b) Alleles

c) Genetic information is passed on from two parent plants.

a)

X Eggs X

X

Sperm:

Y

XX

XX

XY

XY

b) 50%