3b - Inheritance

Question 1

Define inheritance:

Answer 1

transmission of genetic information from generation to generation

Question 2

What is the genome?

Answer 2

the entire genetic material of an organism

Question 3

What is a gene?

Answer 3

a short length of DNA found on a chromosome that codes for a specific protein

Question 4

What is a chromosome?

Answer 4

made up of proteins and DNA organised into genes and are located in the nucleus of cells

Question 5

How many different chromosomes does each cell in a human have?

Answer 5

23 chromosomes

Question 6

Why are there 46 chromosomes in total?

Answer 6

because normal cells have 1 copy of each chromosome

Question 7

How many chromosomes do gametes have?

Answer 7

only 1, 23 in total

Question 8

What are alleles?

Answer 8

variations of the same gene

Question 9

What is the phenotype?

Answer 9

the actual characteristic expressed by the person’s genes (physical)

Question 10

What is the genotype?

Answer 10

the combination of alleles that a person has that codes for their specific phenotype (genetic)

Question 11

What is the dominant allele?

Answer 11

gene that is inherited from only 1 parent, shown in capital letter

Question 12

What is the recessive allele?

Answer 12

gene that is inherited from both parents, shown in lower case letter

Question 13

What does homozygous mean?

Answer 13

when the two alleles of a gene are the same (bb)

Question 14

What does heterozygous mean?

Answer 14

when the two alleles of a gene are different (Bb)

Question 15

What does polygenic mean?

Answer 15

characteristics that are controlled by more than one gene

Question 16

What is monohybrid inheritance?

Answer 16

inheritance of characteristics controlled by a single gene

Question 17

What is the male genotype of a human?

Answer 17

XY

Question 18

What is the female genotyoe of a human?

Answer 18

XX

Question 19

What are diploid cells?

Answer 19

all human cells that have 46 chromosomes

Question 20

What is mitosis?

Answer 20

• a diploid cell makes a copy of each chromosome
• chromosomes line up in the center where they are pulled apart
• the nucleus divides to produce 2 identical daughter cells

Question 21

Why is mitosis important?

Answer 21

• all cells in the body are produced by mitosis

- important for growth and replacing cells

Question 22

What are haploid cells?

Answer 22

• cells that have 23 chromosomes (gamete cells)

Question 23

What is meiosis?

Answer 23

• diploid cell makes a copy of each chromosome
• maternal and paternal chromosomes mix together
• first division: diploid cell divides to produce 2 new diploid cells with mixed chromosomes
• second division: the 2 new diploid cells divide to produce 4 haploid cells that are genetically different to each other

Question 24

Why is meiosis important?

Answer 24

• produces gametes

- increases genetic variation of offspring

Question 25

How many cells does mitosis produce?

Answer 25

2 cells

Question 26

How many cells does meiosis produce?

Answer 26

4 cells

Question 27

What type of cells does mitosis work with?

Answer 27

diploid cells (46 chromosomes)

Question 28

What type of cells does meiosis work with?

Answer 28

haploid cells (23 chromosomes)

Question 29

Mitosis produces genetically _________ cells

Answer 29

identical

Question 30

Meiosis produces genetically _________ cells

Answer 30

different

Question 31

What are some examples of genetic variations?

Answer 31

- blood type - eye colour - ability to roll tongue

Question 32

What are some examples of environmental variations?

Answer 32

- a plant in the shade will grow taller to reach more sunlight

Question 33

What are mutations?

Answer 33

mutations are random changes that occur in a gene or a chromosome and it can be inherited

Question 34

What is evolution?

Answer 34

the change in the frequency of a phenotype in a population over many generations

Question 35

What is an antibiotic?

Answer 35

a chemical that can kill or inhibit the growth and reproduction of bacteria

Question 36

What are the problems of overusing antibiotics?

Answer 36

this can lead to mutations and diseases being harder to control