1

Unit 2 Reproduction

Pages 106-221

2

Section 4-1 Function of the Nucleus Within the Cell

Pages 112-121

3

4.01 Recognize that the nucleus of a cell contains genetic information and determines cellular processes.

Nucleus is the organelle responsible for

1. Storing heredity information

2. Controlling functions of cells

4

4.01 continued…

3. Contains master set of instructions that determines

a. what each cell becomes

b. how it functions

c. when it will grow and divide

d. when it will die

5

4.01.1 Define traitsParticular feature that can vary in size

or form from individual to individual within a species

Passed on from one generation to another

Inherited from biological parents

6

4.01.1 continued…Examples of traits:

Dominant Traits Recessive Traits Finger hair No finger hair Freckles No freckles Attached ear lobes unattached lobes Widow’s peak No widow’s peak

7

4.01.2 Define heredity. Process through which patterns of

traits are passed on from an individual to its offspring

8

4.02 Explain the role of the nucleus and its contents in determining traits and controlling cell division.

Instructions in nucleus are carried in long, two stranded molecules called deoxyribonucleic acid.

Commonly referred to as DNA

9

4.02 continued…DNA informationCarries the instructions

in the nucleusLong, stranded double-

stranded moleculeForms a helix

structure (Greek word: to wrap)

10

4.02 continued…

11

4.02 continued…Sides of DNA are made up of sugar and

phosphateSteps are made up of four nitrogen bases:

1. adenine (A)

2. guanine (G)

3. cytosine (C)

4. thymine (T)

12

4.02 continued… Bases in a DNA molecule always join in a

specific way:

A always joins

with T

G always joins

with C

13

4.03 Explain the importance of using the terms gene and chromosome properly.

The terms gene and chromosomes are often used to mean the same thing but they have very different meanings.

Gene is a section of DNAChromosomes are made up of genes

14

4.03 continued… http://www.youtube.com/watch?v=GWpoBUi06xM&fea

ture=related

Diagram of THE CHROMOSOME EXPRESS train (page 118)

15

4.03 continued…When a cell is ready to divide, each strand

of loosely coiled DNA folds up further into a compact X-shaped structure called a Chromosome.

16

4.03 continued…Chromosomes within the nucleus are

always found pairsHumans…23 pairs (46) of chromosomesOne pair determines gender (M/F)

XX male

XY female

17

4.03 continued…Genes are found on chromosomesStores information needed to produce

proteins used by the body cellsVary in length from hundreds to thousands

of basesArrangement of bases determines the

protein produced

18

4.03 continued…Each chromosomes contains thousands of

genesProteins determine what body cells will

become and how they will functionSpecialize cells will becomes tissues;

tissues will form organs

19

4.03 continued…Specialized proteins called enzymes

speed up the hundreds of chemical reactions that occur within each cell

Example: Digestive enzymes

20

4.03 continued…

Some proteins act as chemical messengers called hormones

Examples: Growth hormone

21

4.03.1 Define gene. Small segments of DNA located on

specific places on a chromosome

22

4.03.2 Describe chromosomes as being composed of numerous genes.

23

4.04 Example of knowledge of cellular functions has resulted in the new technologies.

See wild, weird, wonderful

Text page 120

24

Section 4.2 Mutations

Pages 122-133

25

4.05 Discuss factors that may lead to changes in a cell’s genetic information.

See notes 4.05.1 to 4.05.3

26

4.05.1 Define mutation. A gene mutation is a change in the

specific order of the bases that make up a particular gene

Change in order of A, T, G, and CDNA sequence read in groups of

three bases.Example: CAT or GCC

27

4.05.1 continuedA base may be Added…an extra base is added

Deleted…one base is missing

Substituted…one base is substituted for another

Example: Added (Inserted)

28

Example: Deleted

29

Examples: Substitution

30

Video for genetics

http://www.teachersdomain.org/resource/tdc02.sci.life.repro.lp_inherit/

http://www.pbs.org/wgbh/aso/tryit/dna/index.html

31

32

4.05.1 continued…

Types of Mutation

1. Positive mutations

Benefits an individual

-Resistance to diseases

(see text page 124 for example of HIV resistant individuals)

33

4.05.1 continued…2. Negative Mutation

a. Harms the individual

b. Reduces the chance that an individual will produce offspring or survive in the environment

Examples: Sickle cell anemia

Cystic Fibrosis

34

4.05.1 continued…3. Neutral Mutation

Does not affect the individual

Example: Coat color of animals such as the Spirit Bear in British Columbia

35

4.05.2 Define mutagen. Substance or factors that can cause

mutations in the DNA of organisms.Examples:

– Cigarette smoke– X-rays– Pollutants

36

4.05.3 Give examples of causes mutations

1. Nature

-Solar radiation

-Radioactive gases

37

4.05.3 continued…2. Human Activity

-Chemicals such as chloroform and mustard gas

-Nuclear radiation