Airdrie AcademyNational Biology

Unit 2 HomeworkName:__________________________

Class:__________________________Homewor

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Homework 1: Producing New Cells Marks /33

1. Name the process of cell division in multicellular organisms. 1 _______________________________________________________________

2. Complete the sentences by choosing the correct word from each bracket. 2

“Cells created by mitosis contain (the same/ different) genetic information as the original cell. They also have (the same/ different) number of chromosomes in their nucleus.”

3. Match the stages to their correct definition using a straight line. 2

4. A cell in the basal layer of skin divides by mitosis to produce new skin cells every 6 minutes. After 10 successive divisions, how many new cells will there be? 1

________________________________________________________________

5. The diagrams (A –F) below show the stages of mitosis but in the wrong order.

a) Put the stages into the correct order using the letters. 1 _______________________________________________________________b) How many pairs of chromatids are there in the cell? 1 _______________________________________________________________

c) What is the diploid number of chromosomes in these cells? 1 _______________________________________________________________

6a) Construct a bar chart to show the information in the table below: 3

Species Chromosome Complement

Kangaroo 12Cabbage 18Earthworm 36Rice 24Guppy 46Human 46

b) Calculate the simplest whole number ratio of chromosomes in:i) cabbage to kangaroo 1 _____________: ____________ ii) rice to earthworm 1

_____________: ___________

c) What is the average chromosome complement for the species listed in

the table? 1 ___________________________________________________________

d) What is the haploid number of chromosomes found in an earthworm? 1 ____________________________________________________________

7. Some bacterial cells multiply every 20 minutes. How many cells would be produced from a single bacterium in 2 hours? 1

____________________________________________________________

8. Below is a brief description of the stages of mitosis. 2

Describe what is happening during the missing stages 2 and 4.

______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________

9. Provide a definition for the term’ multicellular’. 1 ___________________________________________________________________

10. Name a multicellular organism. 1

____________________________________________________________________ 11. Explain how a tissue forms. 1 ___________________________________________________________________

12. Complete the table to describe the specialised cells and their functions. 5

Specialised Cell

Function

Red Blood Controls gas exchange by opening and closing stomata

Root Hair Moves towards egg cell for fertilisation

Xylem

13 a) State the function of a red blood cell and provide 3 ways in which it is specialised to effectively carry out its function.

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_______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________

b) State the function of a sperm cell and explain how it’s specialised structure enables it to perform its function. 2 ________________________________________________________________ ________________________________________________________________ ________________________________________________________________

14. Place the following structures in order of increasing complexity starting with cells: Organs, Tissues, Systems, Cells 1 ______________________________________________________________

[End of Homework 1]

Homework 2: Control & Communication Marks /30

1. Name the two parts of the human body which make up the CNS. 2 ________________________________________________________________

2. The brain is made up of three parts. Complete the table with the functions of each section of the brain.

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3. A scientist measured the reaction times of five students before and after drinking alcohol. Average reaction times were calculated for each student. The graph below shows their average reaction times before and after drinking alcohol.

a) What conclusion can be drawn about the results? 1 _______________________________________________________________

b) Why did the scientist calculate the average reaction times? 1 _______________________________________________________________

c) What was the percentage increase in the average reaction time for student 4 after drinking alcohol? 1

_________________________________

d) In this investigation, the students had to press a switch when a light flashed. Which part of the brain co-ordinates this movement? 1 _______________________________________________________________ 4. Name the 3 type of neurons in the human body. 3 _______________________________________________________________ _______________________________________________________________

5. There are tiny gaps between neurons. What are these gaps called and explain how information is passed between them? 3 _______________________________________________________________ _______________________________________________________________6. What is the purpose of a reflex response? Provide two examples of reflex responses in your answer. 3 _______________________________________________________________ _______________________________________________________________ _______________________________________________________________

7. The diagram represents the structures involved in a reflex arc in a human.

a) Complete the table below with the correct letters and functions. 4

Stage LetterStimulus detected by receptors

AInter neuron quickly passes information from sensory to motor neuron.

DEffector muscle which carries out response F

b) Describe the response which would be expected in the above example. 1 ______________________________________________________________

7. What are ‘hormones’ and how are they transported around the body? 1 ______________________________________________________________

8. Complete the following sentences by underlining the correct option. 3

“Glucose is stored in the (pancreas/liver) as glycogen. If blood glucose levels fall the (pancreas/liver) releases (insulin/glucagon) to convert the stored

glycogen back into glucose for use in the body.”

9. Hormones are secreted by different glands in the body. What is the general name of these glands? 1 ______________________________________________________________10. Explain how hormones bring about a response at their target tissue. 2 ______________________________________________________________ ______________________________________________________________ ______________________________________________________________

[End of Homework 2]

Homework3: Reproduction Marks /30

1. The table below shows information on the number of eggs fertilised and the survival of offspring for four different animals.

Animal Average number of eggs fertilised at one time

Average number of surviving offspring

Percentage survival rate

Dog 5 4Human 1 1 100Bird 4 3 75Trout 1000 20 2

a) Calculate the percentage survival for the dog and complete the table with the result. 1

b) Draw a bar graph to show the percentage survival rates of the 4 animals. 3

2. Give the meaning of the following terms: 2a) haploid b) diploid______________________________________________________________________________________________________________________________________________________________________________________________________3. The diagram below shows the summary of events that occur during reproduction in a flowering plant.

Cell Division

Process Q

Process PProcess P

Embryo Cells

Cell R

PollenOvules

Anther cellsOvary cell

a) Complete the diagram by entering the name of cell type R. 1b) Which process from the diagram represents fertilisation? 1 _______________________________________________________________

c) Complete the table by crossing the appropriate box to show which cells are haploid and which are diploid. 2

Cell Type Haploid

Diploid

AntherOvuleCell REmbryo

3. Match the reproductive term to the correct definition. 3 Ovary Site of fertilisation Womb Site of egg production Oviduct Embryo implantation and development4. Choose the correct word from each bracket to make this sentence correct. 2

“ Pollination is the transfer of (pollen/ sperm) from the (anther/ ovary) to the stigma of a flower. This is an example of (asexual/ sexual) reproduction which (increases/ decreases) genetic variation.”

5. Read the passage then answer the questions that follow:“Reproduction for Emperor penguins involves extreme hardship. They start their

breeding cycle in March at the beginning of the Antarctic winter. At this time the fringe of ice that surrounds the Antarctic continent is at its narrowest. The penguins walk across it for several miles to the permanent ice which is their breeding ground. Up to 25000 penguins gather and mating takes place in April. As the temperature falls, the sea ice expands by 2 miles per day. In May the female produces one large egg which she places on top of her feet. The male takes the egg, juggles it onto the top of his feet and covers it with a fold of his densely feathered abdomen to keep it warm. Producing the egg has taken a significant proportion of the female’s body reserves. She needs to replenish them urgently and heads back to the sea to feed.

As the winter winds begin to blow, the temperature falls. The male Emperors huddle closer together for warmth and shelter. They use their tiny stump of a tail as a third leg of a tripod and rest on their heels. Their upwardly turned toes keep their precious egg off the ice. There is nothing to eat and for a month there is total darkness.

After 60 days the eggs hatch. The males, close to starvation, manage to produce a little milky secretion from their gullets for their chicks. At this critical moment he females reappear. They have had a long journey as the ice has extended considerably. The females regurgitate their chicks’ first real meal. The males now start the long trek to the sea to feed for the first time in four months.

3 weeks later, the males are back to take over the care of the chicks, allowing the females to return to the sea. As winter slackens its grip, the ice begins to break

up. The journey to the sea gets shorter and the parents can increase the frequency of feeding. In November the parents stop feeding the young and long processions of adults and young waddle down to the sea.” a) Why is it necessary for the females to leave their eggs and return to the sea? 1 _______________________________________________________________ _______________________________________________________________

b) By how much has the distance to the sea increased in the time between laying and hatching? 1 ________________________________________________________________

c) How long does a male keep his egg off the ice? 1 ________________________________________________________________

d)The following list describes events in the life of emperor penguins. 5 1 – Walk to breeding grounds.2 – Mating3 – Egg Laying4 – Eggs hatch and females return5 – Parents and chicks waddle to seaComplete the time line by placing the number of each event in the correct month.JAN FE

BMAR AP

RMAY JUN JUL AU

GSEP

OCT

NOV

DEC

e) How many months of the year are not spent breeding and rearing young? 1 ________________________________________________________________

6. Explain how a sperm cell is suited to its function. 2

________________________________________________________________ ________________________________________________________________

7. Name the structure in the male reproductive sstem that carries both sperm and urine out the body.

1 ________________________________________________________________

8. Where does fertilisation occur in mammals? 1 ________________________________________________________________ 9. How many eggs are fertilised for the production of identical twins? 1 _________________________________________________________________

10. Draw a diagram to show the 4 stages of fertilisation in plants. 1

Stage 1 Stage 2 Stage 3 Stage 4

[End of Homework 3]

Homework 4: Variation and Inheritance Marks /30

1. Provide the definition for the term ‘Allele’. 1 _______________________________________________________________

2. Candytuft is a plant with white or pink flowers. The two forms of the gene responsible for the flower colour are:

P = pink flowers and p = white flowers

a) A plant breeder crossed two pink flowered plants as shown below. 1 Parents Pp x Pp

What is the expected ratio of pink to white flowered plants in the offspring?

________________________________________________________________

b) If 48 offspring had been produced, how many white flowered plants would have been expected? 1 _______________________________________________________________ c) The offspring actually consisted of 24 pink flowered and 16 white flowered plants. What is the simplest whole number ratio of pink to white flowered plants in the offspring? 1 ________: ________ Pink White

3. Why is the expected ratio in any genetic cross different from the actual ratio? 1 _______________________________________________________________

4. Name the two types of variation. 2 ________________________________________________________________ ________________________________________________________________

5. What is meant by a recesive allele? 1

______________________________________________________________

6. Match the following terms to their definitions by placing the appropriate letter nexnext to the term in the box below. 15

Gene A -Second filial generation in a monohybrid cross2- Alleles B -Different forms of a gene3 – Genotype C -Allele which is masked by the dominant allele4 - Phenotype D -Genotype with the same alleles of a gene5 - Dominant E - Genotype with different alleles of a gene6 - Recessive F -Another term for homozygous where the same

alleles are present in the gene pair7 - Monohybrid cross G -Section of a chromosome which controls a characteristic8- Homozygous H -Type of variation shows clear-cut, distinct values9 - True breeding I -Cross involving two true breeding

parents who differ in the alleles of one gene

10 - Heterozygous J -Combination of genes in a gene pair11 - P K -Physical appearance of a characteristic12 - F1 L -First filial generation in a monohybrid cross 13 - F2 M -Allele which always shows in the phenotype14 - Continuous N -Parental generation in a monohybrid cross 15 - Discrete O -Type of variation which occurs over a wide range

7. State 2 human characteristics which show continuous variation. 2 ________________________________________________________________

8. In gerbils, agouti coat colour is dominant to white. Some heterozygous gerbils were allowed to interbreed and 56 offspring were produced. What would be the expected number of agouti gerbils?

1

_______________________________

9. Explain the term ‘ True- Breeding’ with reference to the alleles present. 1 _______________________________________________________________ _______________________________________________________________

10. Coat colour in labradors is an inherited chracteristic. Black coat colour (B) is dominant to chocolate coat colour (b).

a) A homozygous dominant black labrador was crossed with a chocolate coloured coat. What will the F1 phenotype be from this cross? 1 _______________________________________________________________

bi) Explain what is meant by ‘polygenic inheritance’. 1 _______________________________________________________________ _______________________________________________________________

ii) State the type of variation shown by polygenic inheritance. 1 ______________________________________________________________ _______________________________________________________________

[End of Homework 4]

Homework 5: Transport Systems; Plants Marks /15

1. Complete the table comparing the vessels: 4Vessel Substance

TransportedAdditional Structural Components

Xylem

Sugars

2. Explain with reference to processes and vessels, the ‘Transpiration Stream’. 3 _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________

3. Name the structures involved in the opening and closing of the stomata. 1 _________________________________________________________________

4. The following graph shows the rate of water gain and water loss by a plant during a 24 hour period in summer.

ai) How long after the time of maximum water loss did the plant show its maximum water gain? 1 __________________________________________________________________ii) At what time in the morning did the rate of water gain exactly balance the rate of water loss? 1 _____________________________________________________________________

bi) Name the plant tissue which transports water from the roots to the leaves. 1 ____________________________________________________________________

ii) Name the pores in plant leaves through which water vapour is lost. 1 _____________________________________________________________________6. The diagram below represents a tissue found in the stem of a plant.

(a)Name the tissue shown and state its function. 1Tissue: __________________Function: _____________________________________________________________________________________________________________________

(b)Name Structure A and Cell B. 2A: ____________________________________________________________B: ____________________________________________________________

[End of Homework 5]

Homework 6: Need for Transport; Animals Marks /30

1. Valves are present in the heart and in veins. What is their purpose? 1 ____________________________________________________________________2. Describe the pathway of blood through the heart beginning at the Vena Cava. 1

_____________________________________________________________________ _____________________________________________________________________ _________________________________________________________________3. Complete the table to compare the 3 main blood vessels in the body: 5

Vessel Channel Diameter

Pressure in Vessel

Artery HighWideNarrow

4. The diagram below represents a structure found in the small intestine. The arrows show the direction of the flow of fluids through the structure.

a) Name the structure shown. 1 ___________________________________________________________________b) Which letter identifies the position of the fluid with the highest fat content, after the absorption of digested food? 1 ______________________c) Which letter identifies the position of the fluid with the highest glucose content, after the absorption of digested food? 1 _____________________d) The process of diffusion is important in living organisms. Name 2 substances

which must be able to enter cells by diffusion. 2 ____________________________________________________________________ ____________________________________________________________________5. Complete the sentence by filling in the correct words. 4

“ The _________ artery carries blood away from the heart to the _______.

________ blood re-enters the heart through the pulmonary _____.”6. Name the 2 types of special white blood cells involved in immunity. 2 ____________________________________________________________________7. Explain the process of ‘Phagocytosis’ with reference to the immune system. 2 ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________8. The effect of changing the carbon dioxide concentration in inhaled air on a person’s breathing was investigated. The table below shows the average volume of air inhaled each minute at different concentrations of carbon dioxide.

CO2 conc. In inhaled air (%)

0 2 4 6 8

Avg volume of air inhaled (litres per minute)

8 12

16 24 60

a) Calculate the average volume of carbon dioxide entering the lungs each hour when the carbon dioxide concentration in the air is 4%. 1

_______________________

b) Calculate the increase in the average volume of air breathed per minute when the carbon dioxide concentration changes from 0% to 2% and from 6% to 8%.

Express these increases as a simple whole number ratio. 1

__________:___________

c) How many times greater is the average volume of inhaled air per minute when the carbon dioxide concentration is increased from 2% to 8%? 1

________________

9. The diagram below represents an alveolus in a human lung.

a) Suggest why the lining of the alveolus is thin. 1 ____________________________________________________________________ ____________________________________________________________________b) Name a substance which diffuses from the alveolus into the blood capillary. 1 ____________________________________________________________________c) Name a substance which diffuses from the blood capillary into the alveolus.

1 _____________________________________________________________________d) Describe what happens to oxygen when it enters a red blood cell, including the name of the compound produced. 2 _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________10. The following diagram shows a cross section of some villi in the small intestine.

Explain why the structure and number of villi make absorption an efficient process in the small intestine. 2_____________________________________________________________________________________________________________________________________________________________________________________________________________________ [End of Homework 6]