Chaoter 6.1

Question 1

Give an example of an visible genetic difference

Answer 1

-Coat colour of llama

Question 2

Give an example where the genetic difference isn’t visible

Answer 2

-Owls

Question 3

What is genetic diversity?

Answer 3

-variation or inherited genetic difference in a species

Question 4

Give 2 facts about genetic diversity.

Answer 4

• result of sexual reproduction

- randomly sorts, shuffles DNA

Question 5

What is diploid number?

Answer 5

-Body cell that has two sets of chromosomes

Question 6

What is the human diploid number?

Answer 6

46 (23x2)

Question 7

How does mitosis help diploids?

Answer 7

-Makes sure diploid number always stays the same and genetic information contained in body always remain the same unless mutation

Question 8

Why does genetic diversity within a species is more advantage than a species with no genetic diversity?

Answer 8

Organisms will have combinations of genes from parents, allow it to cope with changes in environment

Question 9

What is haploid number?

Answer 9

One set of 23 chromosomes from female parent and one set of 23 chromosomes from their male parent

Question 10

What are haploid chromosomes carried in

Answer 10

Gametes

Question 11

What are gametes?

Answer 11

Specialized cells necessary for reproduction

Question 12

What are male gametes called

Answer 12

Sperm

Question 13

What are female gametes called

Answer 13

Egg cells

Question 14

What is fertilization

Answer 14

The process which an egg cell is penetrated by a species cell and haploid genetic information from sperm and egg cells combine

Question 15

What is a zygote

Answer 15

New diploid cell formed by fertilization,

Half chromosomes from female half from male

Question 16

What is embryo

Answer 16

The stage of a multicellular organism following fertilization

Question 17

What is the difference between a zygote and embryo

Answer 17

Zygotes undergoes mitosis

Cell division developes into embryo

Question 18

What is meiosis

Answer 18

Process that produces sperms and eggs

Question 19

Name the steps of meiosis

Answer 19

Meiosis 1:

• Prophase 1
• Metaphase 1
• Anaphase 1
• Telophase 1
• interkinesis

Meiosis 2:

• Prophase 2
• Metaphase 2
• Anaphase 2
• Telophase 2
• Cytokinesis

Question 20

Why is meiosis important?

Answer 20

Without meiosis, joining of sperm and egg cell during fertilization would produce offspring with two times original number of chromosomes

Question 21

What are the homologous chromosomes

Answer 21

A pair of matching chromosomes

Question 22

Describe the steps of meiosis 1

Answer 22

Prophase 1: homologous chromosomes pair up, crossing over

Metaphase1: homologous chromosomes pair up at equator

Anaphase1: homologous chromosomes separated by SPINDLE
FIBRES, independent assortment

Telophase1: one chromosome from
homologous pair at each pole of cell

Interkinesis: stage between cell division, cell grows and makes protein NO REPLICATION OF DNA

Question 23

Describe the steps of meiosis 2

Answer 23

Prophase 2: one chromosome of homologous pair in each cell

Metaphase 2: chromosomes from single line across middle

Anaphase 2: sister chromatids move to opposites poles of cells

Telophase 2: spindle fibres begin to disappear, nuclear membrane forms around each set chromosomes

Cytokinesis: two daughter cells seperated

Question 24

What is the result of meiosis 1

Answer 24

-2 diploid cells, 46 chromosomes

Question 25

What is the result of meiosis

Answer 25

-4 diploids, 23 chromosomes

Question 26

What is crossing over?

Answer 26

Parts of non sister chromatids "cross over" each other and exchange segments of DNA

Question 27

What is the result of crossing over?

Answer 27

- Each chromosomes picks up new genetic information from the other - multiple crossovers can occur between 2 chromosomes, can creat infinite genetic possibilities

Question 28

What is independent assortment

Answer 28

-homologous pairs of chromosomes seperated and sort themselves into daughter cells; shuffling of genes

Question 29

What happens during independent assortment

Answer 29

-homologous pairs of chromosomes seperate at equator and move towards opposite poles of cell

Question 30

What is gamete formation in males

Answer 30

- Meiosis 1 occurs and produces 2 cells, followed by meiosis 2 if there's enough nutrients for cell division - 4 cells within cytoplasm and organelles equally divide among them

Question 31

What is the gamete formation in females

Answer 31

Meiosis 1 occurs and produces 2 egg cells, unequal division of cytoplasm and organelles After meiosis 2, threes egg cells disintegrate, one large egg cell remains most of cytoplasm, available for fertilization

Question 32

Describe chromosome mutations in meiosis

Answer 32

- parts of chromosome can be inverted, - parts of chromosome can be duplicated - parts of chromosome can be lost or deleted - parts of chromosome came move to a different region in the chromosome

Question 33

When do chromosome mutations occur?

Answer 33

-cells exposed to mutagens (radiations or chemicals)

Question 34

Describe mutations in meiosis 1 and meiosis 2

Answer 34

Meiosis 1: homologous chromosomes fail to seperate Meiosis 2: sister chromatids fail to seperate

Question 35

What is the result of mutations

Answer 35

-one gamete will have two copies of chromosomes, other will have no copy of that chromosome

Question 36

What is a karotype?

Answer 36

Photograph that shows number of chromosomes a person has, the size, shape

Question 37

What is karotypes for

Answer 37

Used to diagnose genetic disorders

Question 38

How are karotypes prepared?

Answer 38

Cutting and pasting chromosomes from body cells during mitosis

Question 39

How are homologous chromosomes identified (karotypes)

Answer 39

-paired by size, centromere location and banding patterns

Question 40

What is a syndrome and give an example.

Answer 40

Particular disease or disorder with a specific group of symptoms that occur together Down syndrome

Question 41

Describe people diagnosed with Down syndrome

Answer 41

- characteristic facial features, - - shortie stature - prone to develope heart defects and disease (Alzheimer's, leukaemia)

Question 42

What percent of people are caused by extra 21 chromosomes

Answer 42

95%

Question 43

What's is sexual reproduction

Answer 43

- Requires 2 parents | - produces offspring genetically different from parent or any member of the same species m