S3 Biology - Extension – Unit 2

Cells, Tissues and Organs

Homework Exercise 1

Q.1. Cells within the human body can be described as ‘specialised’, explain what this term

means. (1)

Q.2. The diagrams below contain examples of specialised cells.

Match each of the diagrams to the correct description of their function.

(3)

Q.3. Explain why the heart is described as an organ and not as a tissue. (1)

Q.4. Organise the list of terms below into the table by placing them under the correct

headings.

Sperm Eye Muscular Red Blood Root

Nervous Egg Lung Liver

(3)

Q.5. Give an example of a specialised cell and describe how it is specialised to carry out

its function. (2)

Cell Tissue Organ

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1 2 3

a b c

S3 Biology - Extension – Unit 2

Stem cells and Meristems

Homework Exercise 1

Q1. Which of the following statements correctly describes properties of stem cells?

(2)

Q.2. The diagram to the right shows a root from a plant.

Which letter shows the position of a meristem? (1)

Q.3. Complete the sentences below by underlining the correct word.

Meristems are specialised/non-specialised cells found in animals/plants .

The cells which are produced can become one/many type(s) of cell. (3)

Q.4. Complete the following sentences using words from the word bank. (4)

Stem cells are body cells with the ability to develop into _____________ types of

_____________ that can be used in the body to treat disease or _____________. Scientists

hope that one day _____________ cells will be used to grow new _____________such as

_____________or spinal cords, as well as different types of tissues such as nerves and

______________. Stem cells can be taken from _____________which is very controversial;

adult stem cells are a preferred alternative.

1. They are found in animals

2. They produce non-specialised cells

3. They are involved in growth and repair

4. They are found in plants

5. They produce specialised cells

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embryos tissues muscles injury stem

cells kidneys many organs

Reproduction homework 1

1. a) Why must organisms reproduce?

_______________________________________________________________________________

1

b) Complete the table below to show the features of sexual and asexual reproduction. Place a tick to show whether the feature is true of asexual reproduction or sexual reproduction.

Feature Asexual Sexual

One parent is involved

Increases variation in the population

Offspring are the same as the parent

Involves sex cells such as sperm and egg

2

c) Give one example of asexual reproduction in plants.

_______________________________________________________________________________

1

2. The diagram below shows a cross section through a flower.

Complete the table below to show the letter, name and function of parts A, B and C.

2

3. a) Draw an X on the following diagram to show where the pollen tube reaches when its growth is completed.

1

b) Describe the function of the pollen tube.

_______________________________________________________________________________

_______________________________________________________________________________

1

c) The following statements refer to the stages that occur after pollination.

A Fertilisation takes place

B A pollen tube grows out from a pollen grain

C The ovules forms a seed and the ovary forms a fruit

D The pollen tube grows down through the stigma

E The male gamete moves towards the ovule

F The pollen tube grows through the ovary wall

Use the letters of the statements to complete the sequence of stages.

2

Reproduction homework 2

1. The diagrams below represent parts of the human male and female reproductive systems

Complete the table below by adding the correct letters, names and functions of the labelled

structures.

3

2. Use words from the list to complete the following sentences. Each word may be used once, more

than once or not at all.

List water nucleus membrane

ovary oviduct uterus

Fertilisation occurs when the ____________________ of a sperm fuses with the

____________________ of an egg cell. In mammals this happens inside the female body in the

_______________________. In most fish, sperm are deposited in the surrounding

____________________ close to the eggs.

2

3. a) Tick the boxes in the table to indicate whether each of the following statements is true for eggs,

sperm or both.

Statement Eggs Sperm

Contain a food store for developing fetus

Swim using a tail

Produced in the testes

In most fish, are deposited in the water

Are sex cells (gametes)

2

b) How many chromosomes are there in each human egg cell?

_______________

1

c) What term is used to describe the chromosome complement of sex cells?

____________________________

1

d) The following list contains descriptions of stages in the reproduction of a mammal.

A A sperm fertilises an egg

B The embryo develops in the uterus

C The embryo becomes attached to the uterus wall

D A fertilised egg passes down the oviduct

E The young animal is born

Arrange the stages into the correct order by writing the letters into the boxes.

1

Sexual and Asexual Reproduction Homework

1. The special word for a sex cell is a

a. Chromatid

b. Zygote

c. Chromosome

d. Gamete

2. The diagram shows the male sex organs in a mammal

a. Which letter represents the part that produces sperm cells?

b. How many sperm cells are needed to fertilise an egg cell?

3. The diagram shows a section of a typical flower.

Copy and complete the table to show the names of the labelled parts and what they

produce.

Part Name of part What it produces

X

Y

4. The following table gives the diameter of a human fertilised egg at various stages in

the early development.

Stage Diameter (mm)

Fertilised Egg at fertilisation

Embryo at 4 days

Embryo at 10 days

Embryo at 24 days

0.2

0.2

0.5

2.2

On the graph paper, complete the graph by plotting a line graph to show this

information

5. Two samples of sperm from a human male were collected. The table gives the

volumes of the samples and the number of sperm cells contained within each.

a. Copy and complete the table to show the number of sperm cells per millilitre

for each sample.

Volume of sample (ml) Number of sperm cells

(millions)

Number of sperm cells

per ml (millions)

3.5 63

4.0 84

b. Calculate the average number of sperm cells produced per millilitre.

c. Describe an improvement to the procedure which would be needed if a more

reliable average number of sperm cells per millilitre is to be calculated for

this individual.

6. In a human population of 180 individuals, 100 were male and 80 were female.

Calculate the whole number ratio of males to females

7. The diagram shows a section through a flower with various structures labelled by

letters.

a. Copy and complete the table using letters from the diagram to identify the

sites of the processes.

b. What name is given to the cell formed by the fusion of the male and female

gamete.

c. What is the name given to the process that results in the production of this

cell.

8. The table below compares some of the aspects of reproduction in cod and wildcat.

a. Copy and complete the table below by filling in the blanks from the word bank

below.

Word Bank: Cod Wild Cat Internal External 3-7 million 4

Organism Number of eggs

or young

produced at a

time

Type of

fertilisation

Where

development takes

place

Water

Womb/Uterus

b. Give one reason why cod produce large numbers of eggs in order for this kind

of fish to survive.

c. Give one reason why the offspring of the wildcat have a high survival rate

after birth.

9. A team of scientists carried out a survey on caterpillars of the Large White

Butterfly. They looked what happened to a sample of 500 caterpillars between

hatching and turning into butterflies. Their results are in the table.

Cause of death Number % of caterpillar

Diseases of caterpillars 260

Parasites of caterpillars 150

Eaten by birds 50

Diseases of pupae 25

Parasites of pupae 10

a. Copy and complete the table by calculating the percentage of caterpillars for

each cause of death.

b. How many of the caterpillars that hatched survived to become butterflies?

c. What percentage of caterpillars became butterflies?

d. Draw a pie chart to show what happened to all the caterpillars.

Homework Exercise 1 Marks

1. (a)

The diagram below shows stages of asexual reproduction in a single-celled animal called Amoeba but not in the correct order.

(i) Name the type of asexual reproduction carried out by Amoeba. (1)

(ii) Using the letters of the diagrams of Amoeba above, show the stages of asexual reproduction in the correct order, starting with letter P.

(1)

(b) Why are the offspring produced by asexual reproduction called clones? (1)

2. Copy the table below. Tick () boxes in the table to indicate whether each of the following statements is true for eggs, sperm, or both.

Statement Eggs Sperm

Contain a food store for developing foetus

Swim using a tail

Produced in testes

In most fish, are deposited into the water

Are gametes

(2)

P

S R

Q

Marks

3. (a) The following line graph shows the growth of a trout during its first 10 years.

Answer the following questions from the information given in the graph.

(i) What length was the trout at 2½ years of age? (1)

(ii) During which year did the trout grow fastest? (1)

(iii) At what age was the trout fully grown? (1)

(iv) Express as a simple ratio, the length of the trout at 4 years of age compared to that at 1 year old. (If you need help with working out a ratio turn to page 8.)

(1)

(b) What is the name given to the part of a newly hatched trout fry that contains its food? (1)

(10)

Homework Exercise 2 Marks

1. The diagrams below show different stages in the development of a frog but not in the correct order. Write down the letters of the stages in the correct order starting with stage A.

(2)

2. The diagram below shows inside a bird’s egg with the developing embryo.

(a) Which two parts of the egg are sources of food for the bird embryo? (1)

(b) Why is it important that the shell of the egg is porous? (1)

(c) Give one way in which the parents can increase the chances of the survival of the developing bird embryo.

(1)

shell

amniotic fluid

albumen air space

yolk

embryo

A B C

D E F

Marks

3. The diagram below shows a human foetus in the womb at 5 months.

State two ways in which the placenta assists the developing foetus. (2)

4. The following table shows aspects of reproduction in two animals.

Number of eggs or young produced at a time

Type of fertilisation Where

development takes place

cod 3 – 7 million external water

wild cat 4 internal in uterus

(a) Give one reason why the cod must produce large numbers of eggs in order for this kind of fish to survive.

(1)

(b) Give one reason why the offspring of the wild cat have a high survival rate after birth. (1)

5. A female rabbit had 5 litters during one year; giving a total of 30 young. Of the young rabbits, 3 were still-born, 9 were eaten by predators and 6 died from disease. What percentage of the young survived to the end of the first year? (If you need help with working out a percentage turn to page 8.)

(1)

(10)

placenta

womb

Homework Exercise 3 Marks

1. (a)

Here are several statements about sperm.

1. Sperm contain the male nucleus. 2. Sperm are attracted to egg cells. 3. Sperm are larger than egg cells. 4. Sperm have a tail for swimming.

Which of the above statements are correct? Write down the correct letter from the choices given below. A All are correct

B 1, 2 and 3 only are correct

C 1 and 2 only are correct

D 1, 2 and 4 only are correct.

(1)

(b) Where are sperm produced in a mammal? (1)

2. Copy the key and the table. Complete the table correctly by inserting the appropriate key letter or letters beside each of the statements 1 to 6. Key: M for Scottish mammals F for fish O for neither Scottish mammals nor fish

Statement Key letter(s)

1. Fertilisation is always internal

2. Embryo gets most of its food from the yolk

3. Embryo develops in the uterus (womb)

4. Oxygen can be obtained by exchange from mother’s blood

5. Embryo develops in a shelled egg

6. Embryo develops in a watery medium

(3)

Marks

3. The diagram below shows the life cycle of the Atlantic Salmon. The salmon are able to swim between their breeding grounds in Scottish rivers and their feeding grounds in the Atlantic Ocean.

(a) From where do the young fry obtain their food? (1)

(b) Sea lice are a pest of adult salmon. Suggest, from the information given, why they never attack fry or parr.

(1)

(c) A female salmon lays 8000 eggs but only 5% of them hatch. How many fry will be produced?

(1)

(d) Give two ways in which birds increase the survival chances of their young compared to the trout.

(2)

(10)

HHeellpp wwiitthh RRaattiiooss

A ratio gives a measure of the relative size of two or more groups shown as a proportion.

Example

TThhee lleennggtthh ooff pprreeggnnaannccyy ffoorr aann eelleepphhaanntt iiss 8844 wweeeekkss wwhhiillee tthhaatt ooff aa mmoouussee iiss oonnllyy 33 wweeeekkss.. CCaallccuullaattee tthhee rraattiioo ooff tthhee

lleennggtthh ooff pprreeggnnaannccyy ooff tthhee eelleepphhaanntt ttoo tthhaatt ooff aa mmoouussee.. EExxpprreessss yyoouurr aannsswweerr aass aa ssiimmppllee wwhhoollee nnuummbbeerr rraattiioo..

SSoolluuttiioonn:: eelleepphhaanntt mmoouussee ((NNoottee:: oorrddeerr aass iinn qquueessttiioonn))

8844 :: 33

TThhiiss ccaann bbee ssiimmpplliiffiieedd bbyy ddiivviiddiinngg bbootthh ssiiddeess bbyy tthhee ssaammee ffaaccttoorr ((iinn tthhiiss ccaassee bbootthh ssiiddeess ccaann bbee eevveennllyy

ddiivviiddeedd bbyy 33))..

AAnnsswweerr == 2288 :: 11

HHeellpp wwiitthh PPeerrcceennttaaggeess

Percentages are fractions out of a hundred. When fractions are given as percentages (%) it makes it easier to compare the data. In Biology questions involving percentages often use data from a table or a graph.

Example

The table below shows the results of a study on birds.

Success in hatching of birds’ eggs

Number of eggs laid in a season 20

Number of eggs hatching 12

What is the percentage of birds’ eggs that hatch successfully?

Solution = number hatching 12

original number 18

=> % eggs hatching successfully = 0∙6 x 100 = 60%

= 0∙6 =

Commercial Uses of Plants Homework

1.

2.

The need for transport homework 1

1. a) Why is water an important resource for plants?

________________________________________________________________________________

1

b) Name the vessels which transport water throughout the plant.

_________________________________

1

c) As well as water, what other substances are transported in this vessel?

_________________________________

1

2. An experiment was carried out to investigate the rate of water loss in a cherry laurel tree.

The average rate of water loss was measured every 10 days for 70 days. The results are shown in the table

below.

Time (days) Average rate of water loss (cm3 per hour per kg of tree)

0 5.0

10 4.7

20 4.6

30 3.2

40 2.4

50 3.8

60 2.3

70 2.0

a) Calculate the percentage decrease in rate of water loss between day 0 and day 70.

_____________ %

1

b) Express, as the simplest whole number ratio, the rates of water loss from day 20 and day 60.

__________ : __________

1

c) During which 10 day period was there the greatest decrease in rate of water loss? Tick the correct box.

Day 20-40 Day 30-40 Day 40-50 Day 50-60

1

3. The diagram below shows a plant transport tissue.

a) Name the plant transport tissue shown in the diagram and state the substance it transports.

Tissue_____________________________________________

Substance transported_______________________________

1

b) Name the pores found on the leaves of plants.

__________________________________________________

1

c) What is the function of these pores?

________________________________________________________________________________

1

d) Name the cells which control the opening and closing of the pores.

__________________________________________________

1

/10

The need for transport homework 2

1. a) Oxygen travels around the body in red blood cells. Name the substance found in red blood cells which

combines with oxygen.

_________________________________

1

b) Other than oxygen, name one substance which is carried in the blood.

_________________________________

1

2. The diagram below shows the human heart.

a) Name chamber C.

___________________________________________________

1

b) What is the function of the heart valves?

____________________________________________________________________________

1

c) Name the blood vessels which supply the heart with oxygen.

___________________________________________________

1

3. A student carried out an investigation into the relationship between running speed and heart rate.

She used a treadmill to run at a specific speed for 1 minute and measured her heart rate immediately after.

She rested for 2 minutes before running at the next speed.

The results of the investigation are shown below.

Running speed (km/hour)

Heart rate (beats per minute)

0 70

2 77

4 82

6 95

8 112

10 143

12 175

a) Why was it good experimental practice to rest for 2 minutes in between each test?

____________________________________________________________________________

____________________________________________________________________________

1

b) Draw a line graph to display the student’s results.

3

c) Describe the relationship between running speed and heart rate.

____________________________________________________________________________

____________________________________________________________________________

1

/10

The need for transport homework 3

1. a) Describe the movement of oxygen in the lungs.

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

2

b) Describe one feature of the alveoli and explain how it allows efficient gas exchange.

Feature______________________________________________________________________

1

Explanation__________________________________________________________________

____________________________________________________________________________

1

c) Decide if each of the following statements about the role of cilia and mucus is True or False, and tick

(✓) the appropriate box. If the statement is False write the correct word in the Correction box to replace

the word underlined in the statement.

Statement True False Correction

Mucus is a sticky substance which traps dirt and microorganisms.

Cilia beat downwards to remove the mucus from the lungs.

2

2. The villi which line the small intestine each contain a lacteal and blood capillaries.

Give a brief description of the function of each of these structures.

Lacteal______________________________________________________________________

____________________________________________________________________________

Blood capillaries______________________________________________________________

____________________________________________________________________________

2

3. Food is moved along the alimentary canal by the action of circular muscles.

a) What name is given to this movement of food?

________________________________

1

b) Describe the state of the muscles at positions A and B in the diagram

A______________________________________

B______________________________________

1

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Variation and Inheritance Homework 1

1. A horse and a donkey interbreed and produce a mule which is infertile. Do a horse and a donkey

belong to the same species? Explain your answer. (2)

2. State the two forms of variation and provide an example for each. (2)

3. Copy and complete the following table by inserting the characteristics under the correct heading.

(2)

Tongue rolling stem length attached ear lobes

blood type height tail length in mice eye colour

hand span

Discrete Continuous

4. Copy and complete

The ________ of an individual is the combination of genes that an organism inherited from the

_______. The __________ is the physical appearance that results from the genotype. If a person’s

genotype consists of two alleles that are the same they are said to be ________. If a person’s

genotype consists of two alleles that are _________ they are said to be heterozygous. (2)

5. In a study of variation, a group of pupils collected information on the heights found in the class.

The information on heights is shown below.

Height measurements (cm)

150

146

152

155

162

143

136

153

157

164

144

151

154

169

165

146

152

154

160

158

i) What is the range of heights in the class? (1)

ii) Calculate the average height. (1)

10