Inheritance and selection - mrhardy

Test yourself

Inheritance and selection

Unit A

1 Look at the pictures of the boys. On the picture, circle and label three differences between them.

2 The diagram shows what happens during fertilisation in humans and plants.

a Fill in the boxes using the following words. Each word may be used once, more than once or not at all. sperm cell

egg cell

pollen cell

epithelial cell

nerve cell

b Which part of each cell contains the genes? Continued 452 C

M Winterbottom, 2002, The Heinemann Science Scheme

Test yourself

Inheritance and selection continued

Unit A

3 Write true or false next to each of these sentences.

a Egg cells are large so they can store food. b Genes control the characteristics of a living thing. c Members of the same family are less similar to each other than they are to members of other families. d Fertilisation happens when the tail falls off the sperm. e Sisters look different because they inherit a different combination of genes from each parent. f Sperm cells have a tail to help them swim. 4 Draw arrows between the boxes to show how identical twins are formed.

egg released from the ovary

zygote divides into two separate cells

two cells divide and develop separately into two embryos

fertilisation happens

5 Write down whether these types of variation have been caused by inheritance, the environment or both.

a A scratch on the leg is caused by

.

b Eye colour is caused by

.

c Mass and height are caused by

.

d Blood group is caused by

.

e Intelligence is caused by

.

f Natural hair colour is caused by

. Continued 453 C

M Winterbottom, 2002, The Heinemann Science Scheme

Test yourself

Inheritance and selection continued

Unit A

6 Imagine you want to breed a Dalmatian with lots of spots. Write numbers next to these phrases to show the order in which you would carry them out.

Breed them together. Breed them together. Choose two Dalmatians with lots of spots. Choose two Dalmatians with lots of spots. Look at the offspring. Repeat the process several times. 7 Look at the pictures of the horses. Which of the horses would you breed together if you were involved in:

a horse-racing (where the horses need to have long legs and go fast)? b farming (where the horses need to be strong)?

and

and

c horse-riding for beginners (where the horses need to be small)?

A

D

and

B

C

E

F

Continued 454 C

M Winterbottom, 2002, The Heinemann Science Scheme

Test yourself

Inheritance and selection continued

Unit A

8 Tick the characteristics of an edible fruit that may be selected by plant breeders in selective breeding.

resistance to cold weather nice taste poisonous leaves resistance to rotting 9 Complete the flow chart showing the journey of a pollen cell from a plant being used in a selective breeding programme. Use the words below to fill the gaps. anther

ovary

ovule

stigma

style

paint brush

10 Complete the following sentences. Use the words below to fill the gaps. Each word may be used once, more than once or not at all. different

sexual identical stems asexual cuttings roots leaves

clone

a An identical copy of a living thing is called a

.

b Identical copies of living things are made by reproduction. c Gardeners make identical copies of living things when they take

.

d Spider plants grow new plants on the end of long e Living things made by

. reproduction are all

susceptible to the same diseases.

455 C

M Winterbottom, 2002, The Heinemann Science Scheme