B5. Genes, inheritance and selection

Question 1

What is a phenotype?

Answer 1

The appearance of an organism

Question 2

What is variation?

Answer 2

Differences within species

Question 3

What are the two types of causes of variation?

Answer 3

Environmental
Genetic

Question 4

What is genetic variation?

Answer 4

The genetic material you inherit

Question 5

What is environmental variation?

Answer 5

The environment you live in

Question 6

What is discontinuous variation?

Answer 6

characteristics which fall into distinct groups

Question 7

What is continuous variation?

Answer 7

Characteristics which can be any value between a minimum and a maximum

Question 8

Is discontinuous variation caused by both genetic and environmental

Answer 8

No, only genetic

Question 9

Is continuous variation caused by both genetic and environmental

Answer 9

Yes

Question 10

Give two examples of continuous and discontinuous

Answer 10

Contin - Height, Leaf surface area, skin colour
Discon - Gender, eye colour

Question 11

What are diploid cells?

Answer 11

Normal body cells

Question 12

What are gametes?

Answer 12

Sex cells, sperm and ova

Question 13

What are haploid cells?

Answer 13

Contain half the genetic material of a normal cell

Question 14

When two haploid gametes join together, they form a diploid cell called a?

Answer 14

Zygote

Question 15

What is a genome?

Answer 15

The organisms entire genetic material

Question 16

How are gametes made?

Answer 16

Meiosis

Question 17

How does meiosis work?

Answer 17

It produces 4 haploid cells. ovaries produce ova and testes produce sperm

Question 18

What happens in the second stage of meiosis? ( first stage is the same as mitosis

Answer 18

Chromosomes line up along middle of both cells
Chromosome is pulled in half to opposite ends. Resulting in four haploid cells

Question 19

What is the genotype?

Answer 19

The alleles you have

Question 20

What is an Allele?

Answer 20

Different forms of a gene

Question 21

What are the 5 phases of mitosis?

Answer 21

Interphase
Prophase
Metaphase
Anaphase
Telophase

Question 22

What is homozygous?

Answer 22

Two copies of the same allele

Question 23

What is hetrozygous?

Answer 23

different alleles

Question 24

What is the difference between mitosis and meiosis?

Answer 24

Mitosis - 2 identical daughter cells
Meiosis - 4 haploid cells

Question 25

What is a mutation?

Answer 25

Sequence of DNA bases are altered

Question 26

What is sickle cell anaemia?

Answer 26

Causes red blood cells to form sickle shape which makes them smaller. This stops oxygen and blood reaching areas of the body because of blood clots

Question 27

What is cystic fibrosis?

Answer 27

Sticky mucus is released into trachea, bronchi and alveoli

Question 28

What is evolution?

Answer 28

Gradual change over time in a species

Question 29

How do organisms evolve?

Answer 29

Through natural selection. Genetic variation and mutations

Question 30

What is survival of the fittest?

Answer 30

Genetic variation causes a range of phenotypes so those organisms best suited to their environment will survive and reproduce passing on advantages characteristics to off spring. Less adapted die . This is repeated over a very long period of time

Question 31

What is a fossil?

Answer 31

Fossils are formed when animal and plant remains are preserved in rocks

Question 32

What is classification?

Answer 32

Sorting living organisms into groups

Question 33

Why do scientists classify organisms?

Answer 33

To identify species Predict characteristics Find or show evolutionary links